Thursday, June 30, 2011

Pre-Homo Sapiens Outside Africa

Science is making good progress at developing consensus story based upon multiple lines of evidence of the pre-history of modern humans outside Africa (e.g. DNA, archaeological artifact discoveries, megafauna extinctions).

The core story is that a small subset of the modern human African population (a group with a population of perhaps ten thousand or less) left Africa, rapidly expanded and are the ancestors of all ancestral non-African humans. The Out of Africa event or events took place at one or the other end of the Red Sea, no more recently than 50,000 years ago and quite possibly 100,000 years ago or even 200,000 years ago.

Evidence for the presence of modern humans outside Africa significantly more than 100,000 years ago, is pretty much limited to the isolated Dali remains in China discussed below, whose identification as at least partially modern human is not terribly solid. It would not be terribly surprising for later research to determine that either the classification or the dating of these remains was incorrect.  An older date (e.g. 300,000 years ago) would be suggestive of a pure homo erectus or Neanderthal-Homo Erectus hybrid whose similarities to modern humans were strictly a product of convergent evolution, and would heighten the possibility of a homo erectus extinction event before modern humans arrived outside some isolated refugia like the island of Java.  A younger date (e.g. 65,000 years ago) would suggest a modern human-Homo Erectus hybrid born at a time more consistent with other evidence for the appearance of modern humans in the area.  The date currently assigned to Dali is based on an Ox tooth found in the proximity of the remains and itsn't clearly inconsistent with the surrounding strata, but is hardly a rock solid direct dating of the remains either.  Redating ancient human remains findings isn't particularly unusual unless the original date was based on some virtually irrefutable evidence such as a direct carbon dating of bone material.

Recent discoveries have complicated this scenario slightly. Early modern human populations (either a single one, or each of a couple of them) co-existed and admixed with Neanderthals in small proportions before dispersing across Eurasia, leaving an average of 2.5% Neanderthal ancestry in a somewhat complex scenario that leaves no modern humans with a Neanderthal matriline or patriline ancestor. Proto-populations of Melanesians, and possibly some neighboring populations, co-existed and admixed in fairly substantial proportions (perhaps 7% of modern descendants) with a population genetically similar to an ancient Denisovian DNA sample recovered from an archaic hominin. Apart from these instances of admixture in the last 100,000 years or so, a common modern human ancestor probably split from the ancestors of Neanderthals and Denisovians 400,000 to 1,000,000 or more years ago.

The bulk of human evolution took place entirely in Africa there were a melange of archaic hominin species at many steps of an evolutionary tree whose exact relationship to each other and classification is disputed, even though the general trend is not. Our closest extant primate relative species are the Chimpanzee and Bonobos of Africa which diverged from a common ancestor with us at a time period on the order of 4 to 8 million years ago.

Modern humans were not, however, the first wave of hominins to leave Africa. The two most notable previous waves were Homo Erectus and the Neanderthals. There are also two isolated post-Out of Africa archaic human remain sites whose place in the overall picture of human evolution is unclear, one of which has yielded ancient DNA that appears to have introgressed into Asian populations, particularly Melanesians.

Homo Erectus

The first archaic hominin found outside of Africa, stating sometime between one and two million years ago is Homo Erectus. In Asia, we have Homo Erectus fossils on the island of Java in Indonesia (at three sites), in Vietnam (at one or two sites), in China (two sites) and in South Asia (at one site). With recent redatings, it now appears that all of these Asian specimens are apparently from the early Paleolithic (up to about 300,000 or 400,000 years ago). We also have Homo Erectus fossils in Europe and Africa from the early Paleolithic. Homo Erectus doesn't appear to have reached outer Oceania, Australia, Japan, the Andaman Islands, the Philippines or the Americas.


We have evidence for Neanderthals in Europe and probably the Near East and South Asia starting the the Middle Paleolithic (about 300,000 years ago) until about 30,000 years ago. Neanderthals appear to have rapidly replaced Homo Erectus within its range and there are numerous sites with Neanderthal remains over a wide time period and geographic range. There are something on the order of half a dozen Neanderthal ancient DNA samples that have been recovered.

Dali, Denisovians, Homo Florensis and Other Archaics

We have a single case, probably from 209,000 years ago in China, called Dali, that looks something like a hybrid Homo Erectus/modern human whose proper classification is uncertain. Dali is a couple of hundred thousand years, at least, after the next more recent Asian hominin, but, the next oldest modern human remains anywhere in Asia are more than a hundred thousand years older.

We have fragmentary remains at a single location of a late Middle Paleolithic robust archaic hominin, in the Altai Mountains of Siberia about 40,000 years ago, that is called Denisovian and has yielded ancient DNA samples. It may be a remote branch of Neanderthal, a hybrid of Neanderthal and Homo Erectus, or a branch of Homo Erectus from about 40,000 years ago. Genetic similarities with Melanesians suggest that they one had a much wider distribution.

We have an example at a single location, from perhaps as recent as 18,000 years ago in Flores, sometimes called hobbits, that could be from a relict population of dwarf Homo Erectus (or perhaps dwarf Denisovian).

We have eviendence very early archaic hominins in Europe and Africa in that region that could be called their own species, or could be lumped with Homo Erectus or the Neanderthals respectively, and a few that could be hybrids of Neanderthals and modern humans.

Do Modern Humans Populations Have DNA Traces Of Other Archaic Human Populations And If So, Where Would We Expect To Find Them?

It wouldn't be unthinkable, given the evidence of Neanderthal and Denisovian admixture with modern humans, that there may have been other archaic homininshominins in proportions of the same order of magnitude that was actually observed when ancient Neanderthal DNA was first described and compared to modern human DNA, was predicted a number of years before it was observed from these genetic patterns. Similar methods, looking for a residual of the archaic hominin admixture proportion after contributions to two know ancient DNA sources are backed out, should be able to put meaningful boundaries on how much of our DNA could be attributed to other kinds of ancient admixture.

The fossil record and our knowledge of modern human and archaic hominin population history puts some definite bound on how much more we should expect to find. While I wouldn't be surprised if we found new archaic admixture sources in one or more African subpopulations, I would be surprised if we found many more in non-African populations.

There is no evidence that modern humans and non-Neanderthal archaic hominins ever co-existed in Europe or the Near East. These appear to have been exclusive Neanderthal ranges when modern humans left Africa, and that range for very large geographically. There is also no evidence for Neanderthal populations in most of Asia at any time, and we know what to look for and where to look for it, when searching for Neanderthal traces from experience in Europe.

The fact that DNA from Denisovian remains found in the Altai Mountains is found at levels much more elevated in Melanesians than in other populations suggests several things.

First, the Denisovian population must have had a range as a fairly genetically uniform species that extended from Siberia to the coastal route taken to reach Melanesia in the late Middle Paleolithic era. Yet, typically, there is one one species in the kind of ecological niche that they held at one time, so there were unlikely to be other hominin species present at the same time as the Denisovians whom we know had the right timing, outside areas like islands or mountain valleys that would have been ecologically separated refugia from the rest of the pre-modern human hominin population.

Second, if there were Denisovian populations in mainland Asia that admixed with modern humans, it is likely that it had disappeared due to admixture and extinction not long after contact with the first wave of modern humans that they encountered like the Neanderthals. In the case of Melanesians, there were no subsequent waves of migration to dilute that contribution for something on the order of 40,000 years and the initial population might very well have reached a severe bottleneck at the time of first contact on the literal frontier of human settlement. But, in mainland Asia, subsequent waves of modern human populations, which appear to have replaced the original populations of mainland Asia to a great extent both in waves before and waves after the Neolithic revolution, probably tremendously diluted any archaic human admixture contribution to the first wave population.

Third, even if modern humans did admix with modern humans in ecologically isolated refugia like Flores island, it seems unlikely in the time frame of from modern human appearance to complete archaic hominin extinction that these refugia would have been sources for major population expansions of admixed modern humans. Population expansions would be expected to have their sources in large non-isolated areas, not ecological cul-de-sacs.

Thus, undisovered archaic populations seem most likely to have been present in Africa, where there was much more hominin diversity, and in places outside Africa, seem most likely to have been present in places outside the Neanderthal range that could have formed isolated refugia for archaic hominins like islands and mountain valleys that have not been profoundly diluted by subsequent post-archaic hominin extinction migrations into them.

Some instances of still undiscovered ancient admixture in the genome, even if they are out there, may be confined to single groups of African hunter-gatherers, for example, or people in a few villages in the Caucasus mountains, but seem far less likely to be discovered, for example, in the Han Chinese, or the Japanese, whose predominant ancestors probably didn't arrive anywhere close to their present territories at times when there were still archaic humans in the world.

Even if there are eight different species of archaic hominin that admixed with modern humans in Africa, it is unlikely that more than two or three of those species admixted with ancestors of the modern humans who left Africa or experienced major demographic expansions within Africa with the advent of food production. Archaic human ancestry that made its way into the ancestors of the Bantu population are probably detectable. Archaic human ancestry that made its way only into one or two out of many Khoisan tribes may not be possible to detect, and quite possible may have been culled from the gene pool as some Khoisan tribes survived and others did not over time.

There is also not much evidence for large, diversified populations of non-Neanderthal hominins outside Africa, in the post-Out of Africa era. Homo Erectus seem to have a fairly consistent physical form and not very rapidly evolving tool kit for most of the hundreds of millenia and multi-continental range where they are observed. The DNA admixture evidence seems to suggest something similar about the Denisovians. Like modern humans who left Africa, the Homo Erectus population that left Africa probably had only a small subset of the amount of genetic diversity found in the entire archaic hominin, or even Homo Erectus population of Africa at that time.

Also, it is fair to guess that Homo Erectus, which was displaced by Neanderthals in West Eurasia when they competed and doesn't seem to have had much of an ecological impact, was probably a less effective hunter-gatherer and hence probably maintained a lower population density, than Neanderthals who appear to have had more sophisticated tools and form of social organization. Given how sparse we know the Neanderthal population to have been based on inferences from ancient DNA, i.e., on the order of the ten to twenty thousand for all of Europe in perhaps three only moderately overlapping regional subpopulations, the number of Homo Erectus out there that modern humans could have encounted outside the Neanderthal range may have been pretty modest and unimpressive as competition relative to the much more sophisticated hunter-gatherers who made up the modern human population. The likely very low population numbers for Homo Erectus, perhaps in the high single digit thousands for all of Asia when modern humans arrived on the scene, also would place significant limits on their mutation rates and ability to maintain diversified subtypes, and would also place significant limits on the extent to which they could impact a probably considerable higher population density modern human hunter-gatherer population.

Uniparental Genetic Evidence For An Out of Africa Scenario

All modern humans share a common ultimate maternal ancestor and a common ultimate paternal ancestor in a time frame generally consistent with the appearance of anatomically modern humans.

All non-African modern humans share one of two maternal ancestors who come from one branch of the tree of matrilineal ancestery found in Africa. All non-African modern human men share one of four paternal ancestors who come from branches of the tree of patrilineal ancestery ultimately rooted in Africa. The time frame in which these ancestors became distinct is generally consistent with the timing of an Out of Africa event.

Matrilineal descent

The matriline descendants of all modern human women outside Africa can be traced via mtDNA which passed from mother to child, sometimes with mutations, to two individuals (line "M" and "N"), and it is not clear if matriline descendants of both women were part of a single original Out of Africa group, or if their descendants represent two separate Out of Africa waves. All of the matrilineal descendants of these two individuals in Africa today (mostly in matrilines called "M1" and "U6" in North Africa and East Africa) appear to have been back migrants from Eurasia probably from sometime in the last 8,000 years. None of the other major African matrilines (labelled "L") left Africa until the historic era or not long before that era.

Both M and N are matriline descendants of the African matrilineal ancestors called "L3", with most Africans belonging to matrilines, L0, L1, L2 and L3 (additional matrilines in the L group have been named based on discoveries of small African populations). Currently, the members of matriline L3 most closely related to non-African matrilines are found in the highest frequencies in East Africa.

All of these African matrilines can be traced to a single female ancestor sometimes called mitchodrial eve.

Patrlineal descent

Patrilineal descendant is traced using the non-recombining part of the Y-chromosome which is passed from father to son and sometimes mutates before being passed on again.

Non-Africans likewise trace descendant from two patrilines, "CF" (with only the "F" part accounting for the patrline ancestry of almost all Europeans and the "C" part largely restricted to Asia, Oceania and the Americas) and "DE" (with "E" part of the latter patrline including a large share of all modern Africans, and a quite small share of all non-Africans geographically near Africa, who probably left Africa long after the Out of Africa event, and the "D" part having a curious distribution that includes Tibet and Japan but has big gaps in between areas of concentration). These patrilines can be traced to a common patrilineal ancestors shared with exclusively African patriline "B". All of these patrilines share a common ancestor with the paternal ancestor of all members of exclusive African patrline "A", sometimes called Y-DNA Adam.

The "C", "D" and "E" patrilines probably made their way out of Africa in migrations that did not overlap with each other. The "F" patriline (which probably emerged as a distinct line at least 45,000 years ago) probably had a population that did not overlap with the "D" patrline (which probably took place at least 30,000 years ago), and would have been much earlier than the migration "E" patrilines (which probably took place no more distantly in the past than the last 18,000 years). The "C" and "F" patrline probably became distinct from each other sometime after the Out of Africa population became distinct from the remaining African population. The "D" and "E" patrilines probably became distinct somewhere in Africa not long before ancestors of the lion's share of modern members of the "D" patriline left Africa. The break between the CF and DE patrilines is probably at least as ancient as the Out of Africa event and could reflect an even older population structure within Africa itself prior to the Out of Africa migration.

Tuesday, June 28, 2011

Experiments Constrain Theta 13

Neutrinos oscillate from one flavor (e.g. electron neutrino, muon neutrino, tau neutrino) via the weak force in consistent probabilities that are expressed in the Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrix, which can be expressed through a number of parameters, of which is Theta 13, an angle that influences among other things, the probability that a muon neutrino will turn into an electron neutrino, is among the least well established experimentally. (The equivalent matrix for quarks is called the CKM matrix).

According to Wikipedia, previous studies have suggested that the full range of constants involved if there are three flavors of neutrinos (the minimum number as three have been observed) have values as follows:

sin^2 2θ13 = 0.08. (If it turns out to be much smaller or zero, the small wiggles shown here will be much smaller or non-existent, respectively.)
sin^2 2θ23 = 0.95. (It may turn out to be exactly one.)
sin^2 2θ12 = 0.86.
δ = 0. (If it is actually large, these probabilities will be somewhat distorted and different for neutrinos and antineutrinos.)
(Delta mass)^2 12= 8 x 10^-5 eV^2
(Delta mass)^2 23 approximately equal to (Delta mass)^2 13 = 2.4 x 10^-3 eV^2

The mass differences between flavors are self-explanatory. The three thetas govern probabilities of conversion of one flavor to another. The sigma estimate to be zero is a charge-parity violating term (a phenomena not observed so far).

The MINOS experiment at Fermilab, has released new data that is consistent with, but constrains results earlier this year from the Tokai-to-Kamioka (T2K) experiment in Japan. Both experiements are measuring the theta 13 parameter, but the experiments use different methods to do so.

The results are usually expressed not in terms of the value of the variable itself, but in terms of the sine squared of double the theta 13 parameter. The result from MINOS is 0.04 with a range of values from 0 to 0.12 within the margin of error. The result from T2K is 0.11 with a range of values from 0.03 and 0.28 that would be statistically significant. The range of values consistent with both experiments are 0.03 to 0.12, with the average of the two central predictions being 0.075.

Neutrinos are an attractive place to look for new physics. We've recently confirmed contrary to some theoretical expectations and experiments that showed a mass consistent with zero, that neutrinos do have mass and have constrained the amount of difference between the masses of the different flavors, although the absolute mass of any given flavor of neutrino has not been determined.

At least a couple of experiments within the last year have also shown a best fit to a result with more than three flavors of neutrinos, which would imply at least one beyond the standard model particle, and also makes the possiblity that there are more than three generations of quarks and electrons seem more plausible.

Extra flavors of neutrinos could also help explain how neutrinos get their mass (there are competing theories regarding that point right now), and could provide a dark matter particle if they were stable and heavy enough.

Since SUSY, which is a class of grand unified theories (i.e. GUTs) which explain all of the laws of physics except gravity in a single unified theory and is necessarily a part of the theory of everything (i.e. TOE) which explains all of the laws of physics in a unified way called string theory or M theory, this could be huge deal. By some accounts, four generations of massive spin-1/2 particles are inconsistent with string theory and SUSY.

The comparable constants in the CKM matrix for quarks are known which much more precision than those for leptons and are as follows: θ12 = 13.04±0.05°, θ13 = 0.201±0.011°, θ23 = 2.38±0.06°, and δ13 = 1.20±0.08.

Footnote from the Economist:

Maybe nature is up to more than its usual tricks.

In light of the latest result, it remains unclear whether either the American or the Japanese experiment is precise enough to measure delta. In 2013, however, MINOS will be supplanted by NOvA, a fancier device located in another Minnesota mine 810km from Fermilab's muon-neutrino cannon. That ought to do the trick. Then again, nature has the habit of springing surprises.

And in more ways than one. Days after T2K's run was cut short by the earthquake that shook Japan in March, devastating the muon-neutrino source at J-PARC, the country's main particle-accelerator complex, MINOS had its own share of woe when the Soudan mine sustained significant flooding. Fortunately, the experiment itself escaped relatively unscathed. But the eerie coincidence spurred some boffins, not a particularly superstitious bunch, to speak of a neutrino curse. Fingers crossed that isn't the case.

Monday, June 27, 2011

Quantum Physics Still Necessary Absent Entanglement

Non-local phenomena associated with the entanglement of two particles cannot be interpreted with any classical physics theory and requires the non-deterministic, often non-intuitive, form of reasoning used by quantum mechanics. But, entanglement isn't the only place where it has been definitively shown by experiment that quantum mechanical reasoning is necessary. Even when entanglement is specifically excluded from the experiment, quantum mechanical methods are still necessary:

[A] team of quantum physicists led by Anton Zeilinger from the Faculty of Physics at the University of Vienna and from the IQOQI of the Austrian Academy of Sciences . . . used a "qutrit" -- a quantum system consisting of a single photon that can assume three distinguishable states. "We were able to demonstrate experimentally that quantum mechanical measurements cannot be interpreted in a classical way even when no entanglement is involved," Radek Lapkiewicz explains. The findings relate to the theoretical predictions by John Stewart Bell, Simon B. Kochen, and Ernst Specker.

Underlying source: Radek Lapkiewicz, Peizhe Li, Christoph Schaeff, Nathan K. Langford, Sven Ramelow, Marcin Wieśniak, Anton Zeilinger. Experimental non-classicality of an indivisible quantum system. Nature, 2011; 474 (7352): 490 DOI: 10.1038/nature10119

While the experiment merely confirms what was widely believed to be true already, the more ways that a conclusion is confirmed, the less room there is for an alternative theoretical explanation.

Wednesday, June 22, 2011

The Case For Minoan As Greater Hurrian

On the island of Crete, not long before the Trojan War that was given a legendary and heroic character in Homer's epic poem, the Illiad, there was inhabited by a society we call the Minoans, which was conquered, or at least followed after its cultural collapse, by a linguistically and culturally distinct people whom we know as the Mycenaean Greeks around 1450 B.C.E., give or take a half a century.

Maritime trade has been documented between the Minoans and Egypt's Old Kingdom, copper-bearing Cyprus, Canaan and the Levantine coasts beyond, and Anatolia. Their high palace culture was one of the flashiest and most memorable of antiquity.

Some historians see the volcanic eruption on the island of Thera about 100 km distant from Crete, which took place not long before the demise of the Minoan society as a force that weakened them and made them vulnerable to Mycenaean invaders, and also associate this erruption with the Atlantis myth recounted by Plato, which may have been received by him in a somewhat distorted version through Egyptian historical records of the event.

The Myceneans spoke an early verision of the Indo-European Greek language that is still spoken in Crete today and was written on Crete in a writing system called Linear B until they adopted a simpler writing system, ultimately descended from the Phoenician alphabet, now used by mathematicians, fraternities, sororities, classical literature scholars, Greek people, and in a modified form, called Cyrillic, by most of the nations of Eastern Europe that were historically Orthodox Christian, as opposed to Roman Catholic.

The Minoan language was recorded in writing too, in a script called Linear A , in use from about 1625 B.C.E. until the fall of Minoan civilization, which then formed the basis for the recording of Mycenaean Greek in Linear B.

The Mycenean Linear B script is essentially the same as the (somewhat earlier) Linear A one. The only important differences are (apart from rounding or simplification of some signs) the emergence of a handful of "new" syllabary signs, that cannot be found in any Linear A document (almost all Linear A signs continued to see some use in Linear B, but the reverse is not true).

Linear A may also have been used by the Trojans who were contemporaries of the Minoans.

The Linear A script, however, was used by a far smaller number of scribes, probably numbering in the dozens for the entire period for which we have Linear A texts, for a far narrower range of tasks, mostly related to bureaucratic record keeping for matters like ration entitlements and shipments of goods that would be the province of lawyers and accountants today.

When the Myceneans adopted the Greek alphabet, a small number of documents used it to transcribe statements in a non-Greek language of Crete that was very likely Minoan, those texts are called Eteocretian.

There are other sources for the Minoan language as well.

A small number of Egyptian medical texts, in a form of hieroglyphics that we can translate, phonetically recount Minoan incantations to heal illnesses. There are also ancient Egyptian style guides to explaining to scribes how to write Minoan proper names, as the Egyptians had trade relations with them and a small ex-patriot community of Minoans.

Structurally, these words look and sound a great deal like words in Hattic or Hurrian, which were non-Indo-European languages of Anatolian kingdoms immediately prior to the linguistically Indo-European Hittites (in the case of Hattic) and parallel to them (in the case of the Hurrian language of the Mittani empire), which remained a liturgical language (a bit like pre-Vatican II church Latin or Hebrew prior to its restoration as a living language in Israel) until some time after Bronze Age collapse, a series of major political upheavals in the Mediterrean area including the Trojan War and the collapse of the Hittite empire around 1200 BCE. Hattic and Hurrian are understood today by scholars of ancient languages to a reasonable extent because it was attested in writing by the Hittites and there were some bilingual texts prepared that have assisted the process of deciphering them.

[B]ased on toponyms and personal names, [Hattic] may have been related to the otherwise unattested Kaskian language. Certain similarities between Hattic and both Northwest (e.g., Abkhaz) and South Caucasian (Kartvelian) languages have led to assumptions by some scholars about the possibility of a linguistic block stretching from central Anatolia to the Caucasus.

Today, the closest living language to Hurrian is probably found among the Northeast Caucasian languages, "spoken in the Russian republics of Dagestan, Chechnya, Ingushetia, northern Azerbaijan, and in northeastern Georgia, as well as in diaspora populations in Russia, Turkey, and the Middle East."

We can derive considerable insight into the non-Indo-European languages of the Aegean from a non-Indo-European substrate in Greek, consisting of something on the order of a thousand words with atypical for Indo-European language sound combinations and grammatical forms that seem to show affinity with the non-Indo-European languages of Anatolia. Proper place names of pre-Mycenean origins show continuity with pre-Hittite language proper place names across the Aegean into Western Anatolia, suggesting a common linguistic community, as far as the ancient province of Cilicia, which was approximately as far east as the current coastal border of Syria and Turkey.

Pre-Greek words often show variations which are not found in inherited words. . . . [T]hese variations show certain patterns, so that they can be used to recognize Pre-Greek elements. . . . we have a large corpus of material. . . . it contains some 1000 Pre-Greek etyma. . . .

It is generally accepted, on the basis of the place names, that the same language was once spoken in Greece and in (western) Asia Minor. . . . such forms are found in the south as far as Cilicia . . . . But it is mostly impossible to distinguish between substratum words and - (mostly) later -
loans from Asia Minor. A word may have been taken over through commerce etc., as happens between two neighbouring countries, or since the time when Greeks settled in Asia Minor, which happened probably as early as in the 14th century. . . . from a methodological point, it is better to consider such words as Pre-Greek, and only to take them as - normal - loan words when there is reason to do so, but it is clear that here we may often make mistakes. A good example is . . . `clew, ball of wool ready for spinning'. The word is clearly related with Luw., Hitt. talupa/i- `lump, clod'. The Greek word is typical for Pre-Greek words: CaC-up- (with a = o before u); there is no IE etymology (Melchert, Orpheus 8 (1998) 47-51 does not convince). So it is Pre-Greek / Anatolian. Also, `clew...' is not a word that you bring home from overseas; it is an everyday word, which the Greeks took up at home. . . . the word was brought to Greece by the settlers from Anatolia who brought their language, which, from another perspective, we call Pre-Greek to Greece. So it is a loan fron an Anatolian language, but from the one that was also spoken in Greece before the Indo-European speaking Greeks arrived there. The essential point is that it should be recognized that substratum words are a frequent phenomenon. . . . in this way we can learn something about the old languages of Anatolia, and of the role of Anatolia in early history. And, of course, it is part of the oldest
history of Greece. As to `Pelasgian' and related theories which assume an Indo-European substratum in Greece, these theories have failed . . . `Pelasgian' has done much harm, and it is time to definitely reject it. The latest attempt was Heubeck's `Minoisch-Mykenische' . . . where the material was reduced to some ten words; the theory has been tacitly abandoned[.]

Finally, there is good reason to believe that Minoan was part of the same language family as several other now dead languages of the region that are grouped in the Tyhrrhenian language family that consists of Etruscan, Raetic, and Lemnian. We have a number of fragments of writing in the Lemnian and Rhaetic languages, and considerable volumes of texts that are partially understood, some bilingual or discernable from translations by ancient Romans, of the non-Indo-European Etruscan language once spoken in the general vicinity of what is now Tuscanny, Italy. These languages seem to have strong linguistic affiliations with each other and probably have linguistic affiliations with Minoan as well.

What About The Indo-European Anatolian Languages?

There were several Indo-European languages in Anatolia other than Hittite. Specifically:

Luwian (luwili), a close relative of Hittite spoken in adjoining regions sometimes under Hittite control. Cuneiform Luwian, glosses and short passages in Hittite texts written in Cuneiform script.

Hieroglyphic Luwian, written in Anatolian hieroglyphs on seals and in rock inscriptions.

Lycian (Lycian A; standard Lycian), spoken in Lycia (possibly Lukka) in the Iron Age, a descendant of Luwian, extinct in ca. the 1st century BC, fragmentary. Milyan, also called Lycian B, a dialect of Lycian, known from a single inscription.

Carian, spoken in Caria (possibly Karkija), fragmentarily attested from graffiti by Carian mercenaries in Egypt from ca. the 7th century BC, extinct ca. in the 3rd century BC.

Pisidian and Sidetic (Pamphylian), fragmentary.

Palaic, spoken in the north-central Anatolian region of Pala, extinct around the 13th century BC, known only fragmentarily from quoted prayers in Hittite texts.

Lydian, spoken in Lydia, extinct in ca. the 1st century BC, fragmentary.

There were likely other languages of the family that have left no written records, such as the languages of Lycaonia and Isauria, as well as languages such as Lutescan which are too poorly attested to be sure they are Anatolian.

All of the Anatolian languages ceased to be living languages no later than the 1st century B.C. when Alexander the Great and his successors imposed the Greek language on his Anatolian subjects.

These Anatolian Indo-European languages are particularly well attested in Western Anatolia in the Iron Age, after Bronze Age collapse, and appear to be largely folk languages or simply strong regional dialects of Hittite that grow distinct when there is no longer an empire to standardize them (much as the Romance languages did following the demise of the Roman Empire), rather than languages in which official business is conducted, for the most part, during the reign of the Hittite empire. A few are attested to some degree in Western Anatolia (mostly by references from people writing in other languages, rather than in written form themselves) before the rise of the Hittite empire ca. 1800 B.C.E., such as Luwian and Palaic, but there is little influence that they were dominant and widespread in the region at that time.

In any case, these Indo-European Anatolian languages seem to be implausible linguistic relatives of Minoan which follows a strongly non-Indo-European pattern and has non-Indo-European traits, and which is similar to attested non-Indo-European Anatolian languages. To the extent that there are similarities, they are likely to be substrate influences in these geographically compact, less influential Indo-European Anatolian languages.

Instead, it is reasonable to suppose that the same migration wave, probably driven by climate fluctuations causing widespread regional political distruptions around 2000 B.C.E. that brought the proto-Hittites to Anatolia also swept other bands of somewhat related Indo-Europeans subject to similar non-Indo-European substrate influences into the region and that each of these groups were small recent arrivals just establishing themselves locally in the pre-Hittite era which were not present, or where not a significant political and economic and population force, during the era in which an Anatolian population conquered or filled a political vacuum in Crete around 3100 B.C.E. The Hittites expanded from a single city sometime around 2000 B.C.E. to 1700 B.C.E. to rule almost all of Anatolia and most of the Northern Levant in a few hundred years, and it seems plausible that other newly arrived Indo-European communities were similarly small in scale at that time, if one accepts the very substantial evidence for Indo-European origins outside of Anatolia.

One scholarly 2008 analysis concluded based on PIE verbs rejected "an early separation of Anatolian languages altogether and yield results that place a genealogical split of Anatolian (and Tocharian) within a more recent grouping together with Greek, Albanian and Armenian, in a single branch together with Indo-Iranian, though at distance from the genealogical splits of Balto-Slavic, Italo-Celtic and Germanic that are harboured within another branch, thus supporting proponents of an IE expansion that roughly parallels the adoption of the bronze metallurgy." In my view, this is in accord, at least in the Anatolian case, with the evidence from historical records and archaeology, although it is somewhat more of a stretch in the Tocharian case.

The Big Picture

One does not have to be a particularly zealous "lumper" or make any geographically implausible assumptions to observe that the three main language families of the Caucasus (Northwestern, Northeastern and Southern), Hattic, Hurrian, Minoan and the Tyrrenean language family are probably more closely related to each other in linguistic origins than they are to languages in any other language family.

While beyond the scope of this post to explore in depth, it is also not implausible, in my mind, that these languages, in turn, may also be part of the same macro-language family as the now dead non-Indo-European languages including Sumerian, Kassite, Elamite and Harappan languages. Sumerian was spoken in Mesopotamia (i.e. Iraq). Kassite was spoken in the mountains to the east of Mesopotamia in present day Iran for most of its existence (overlapping Hurrian linguistic territory), but became the language of Sumeria for a while when the Akkadian empire collapsed, in what was viewed as something of a restoration of traditional Sumerian culture. The Elamite language spoken in most of present day Iran (then Persia) had a number of general grammatical similarities with the other non-Indo-European languages of this region, engaged in vigorous trade with Sumeria, and derived its agricultural technologies from Mesopotamia. The Harappan civilization of the Indus River Valley, now mostly in Pakistan, appears to have received its agricultural technology from Mesopotamia, had vigorous maritime trade with and an expatriot community in Sumeria, and appears to have been settled in a single cohesive event that created a polity that was never strained by ethnic or regional divides strong enough to lead to political division or war.

Modern scholarship tends to show that the Harappan cultural area didn't not extend further into India aside from a couple of frontier trade outposts on India's Southeastern coast, probably in part because the Fertile Crescent agriculture package was a poor fit for its climate in some areas, and because it had to compete with early rice agriculture from the east, whose legacy are the Munda language speakers of Northeast India further north.

There is no evidence that any languages or cultures of this broad, non-Semitic, non-Indo-European linguistic grouping ever managed to have a lasting, permanent community in the Levant anywhere but in its very northernmost reaches practically into Anatolia, nor is there any evidence that this linguistic grouping ever penetrated Africa or even Southern Arabia. Even if that happened, all traces of it are probably lost forever to history.

What Is The Time Depth Of The Greater Hurrian Language Family?

There are limits to how far back these languages can be comfortable known to have been present. The Bronze Age Minoan culture appeared in Crete starting around 3100 B.C.E. and seems to represent a pretty major break with the preceding Neolithic cultures of the region which prevailed from about 6000 B.C.E. until asbout 3200 B.C.E. So, there may have been a language shift and a demic shift, at least among the elites, when the Minoan culture emerges in Crete. The language shift brought about by the Mycenaeans may also have been more of an elite phenomena than full fledged demographic replacement.

To the extent that Hurrian and Hattic have affinities to different language families of the Caucasus mountains, these divisions probably date to sometime in the Neolithic era.

"A comparative study of DNA haplogroups of modern Cretan men showed that a male founder group from Anatolia or the Levant, is shared with the Greeks," according to R.J. King, S.S. Ozcan et al., "Differential Y-chromosome Anatolian influences on the Greek and Cretan Neolithic," via Wikipedia.

The Villanovan Etruscans culture arose in the Iron Age as a sharp break from preceding Bronze Age Terramare culture of the area, with the proto-Villanovan culture appearing around the 11th century B.C.E. and recognizably Etruscan cities emerging starting from approximately the 8th century B.C.E. until the 1st century C.E. when it succumbed to the overwhelming influence of the Roman empire. This timing is close in time to the period when Italic language colonies were established in Italy and the Villanovan culture had some similar religious innovations (like cremation) and technological innovations to the Romans. But for the contemporaneous historical accounts in Roman documents and the inscriptions that they left behind, archaeologists would probably have assumed that the Etruscans were a somewhat culturally innovative Celtic or Italic culture, rather than a non-Indo-European one. Etruscan artifacts and cultural features are suggestive of an origin to the north of Italy somewhere between it and the Central European origin of the Urnfield culture which is widely presumed to have been Indo-European linguistically (as a source for both Celtic and Italic languages), but Etruscan origin myths as recounted by the Romans suggest a Lydian origin for them (i.e. near the West coast of Anatolia). Still others suggest that the Etruscan civilization was a cultural innovation of the indigeneous peoples of the region or that their origins were among the "sea peoples" of the Bronze Age collapse era (a population that is increasingly looking like a Mycenaean led, rather than a non-Indo-European population migration). Their origins were controversial even in classical times. The Etruscan language has also been demonstrated to have a significant number of loan words from Afro-Asiatic languages that were probably either proto-Berber or Punic, presumably as a result of maritime trade with North Africa.

Genetic studies attempting to identify the origins of the Etruscans or at least people in the region today, have pointed various to Anatolians, the people of Caucasus, and the Near East, at sometime after farming was invented, and ancient DNA studies have noted significant population replacement at least among Etruscan elites between the Villanovan era and the Roman era, but any number of scenarios from early Neolithic arrival of an indigenous population to migration from these regions via Central Europe to a direct maritime arrival of the Etruscans when their civilization appeared would be consistent with the genetic evidence. An Upper Paleolithic origin for the Etruscans can be ruled out, but the genetics in this case are generally less informative than the archaeology and linguistic evidence.

The Hittites did not have a written language until they adopted the Akkadian writing cuniform writing system not long after their empire started to emerge around 18000 BCE (and there earliest records concerning them are written in the Semitic Akkadian language of the Mesopotamian traders of that time from a century or two earlier), and the Hurrians did not have written language or receive much notice in Akkadian, Sumerian or Egyptian records of that time, so the Hurrian culture has to be dated mostly based on continuities and discontinuities in archaeological cultures, a particularly hard task in Anatolia where some of the first plant and animal domestications of the Neolithic era took place around 8000 B.C.E. and which has been more or less continuously inhabited by some food producing civiliazation or another since then.

Taken as a whole, it seems more likely than not, albeit not a matter of scholarly certainty, that from at least the Copper Age onwards there was a non-Indo-European Greater Hurrian language family (quite a bit broader, in actuality than the more widely recognized and more narrow Hurro-Uratian language family) that extended at its greatest extent from Tuscany to Anatolia (not necessarily without pockets of other languages) and included essentially all of the pre-Indo-European inhabitants of the Aegean. Minoan was likely a linguistic relative of Hurrian, or more likely, the geographically closer Hattic language.

What About Old Europe?

There have been some suggestions that the closet known living lingustic relative of the Basque language is Northeast Caucasian, (a link shared with Hurrian), although this is not a particularly solid claim and the inquiry into the antecedents of the Basque culture and language is a matter beyond the scope of this post, other than to identify some basic boundaries on those speculations. Its geographic remoteness from other dead non-Indo-European languages that are historically attested, and a long history of inconclusive or even absurd efforts to link Basque to any other language family or language isolate in the world past and present, because it does not fit neatly into a language category box bespeaks caution against making inferences based on flimsy evidence when considering the issue.

Separate, although not entirely unrelated to the origins of the Basque culture and language, is the question of what pre-Indo-European languages were spoken in Neolithic Europe. Assuming the general correctness of the Kurgan hypothesis for Indo-European origins, which, at least in broad outline, if not in every specific detail, is the leading theory on the question with good reason, the language of pre-Bronze Age Europeans, for which we have no historical evidence (other than the Vinca script of the greater Balkans, which may be a proto-language that can never tell us much about the spoken language of the first farmers of Europe), we must rely heavily on inference to discern plausible answers.

The first stage of this inference would be to break European pre-history into chunks with apparent culture continuity and interaction prior to the arrival of Indo-European languages that could support a common linguistic family and that might be reflected in Europe's current geography through substrated influences that have shaped Europe's various Indo-European language families.

One obvious chunk involves pre-Neolithic European, Near Eastern and North African hunter-gatherers, who were predominantly replaced by a new population of farmers and herders, and whose languages almost surely died when the remaining populations were assimilated into farming and herding populations or when they entered into intense trading relationships with farming and herding populations of Europe at their fringes. There is no way that these languages, which probably had little impact on the languages of the new arrivals (by way of comparison, Ainu words account for just 1% of modern Japanese words and none of its writing or grammar, and Native American words and grammar have had only trival impact on the European languages spoken in the Americas) - perhaps a few place names or proper names survive, but it is unlikely that there is much more of a linguistic legacy from them. There are good reasons to suspect that the Berber and Saami populations of Europe experienced language shifts (probably around 1000 B.C.E. in the case of the Saami), since their likely genetic origins do not coincide with the likely places of origin of their languages. Efforts to identify hunter-gatherer substrates in these languages have not been very fruitful.

All of the other populations of Europe (including a majority of the genetic origins of the Basques), with the possible exception of some populations of the Baltics who may have epipaleolithic origins as fishing based subsistance populations and may have spoken a Uralic language from the start, probably trace their European ancestors to some time after 6500 B.C.E. and are associated with Neolithic populations. The only attested languages that could even plausible have roots in the hunter-gatherer languages of Europe other than Uralic (which is disfavored for a variety of reasons itself), are the Paleo-Siberian languages such as the Yenesian Ket language.

The next chunk of relative cultural continuity is the first wave of Neolithic populations until at least the Enolithic age -- Danubian farmers and kindred populations in the East, Cardial Pottery non-dairy farmers on Europe's Southern Coast, and megalithic populations in coastal Atlantic regions. Their linguistic affiliations can probably never be known with certainty, but linguistic substrate evidence, ancient proper names, and the linguistic trajectories of the places of origin of these populations may offer some strong inferences on this point.

Those inferences largely point to remote linguistic relationships of these populations to the linguistic group that I have identified as Greater Hurrian, but are not terribly compelling and make sense mostly because there is no real evidence pointing strongly to any other interpretation. There are also other possibilities such as a now lost Afro-Asiatic, pre-Semitic language speaking population of Levantine farmers who might have been part of this wave (and have left a legacy of low levels of Y-DNA haplgroup E and haplogroup T types), the possibility of totally lost language famillies, and the lingering question of what strange brew of circumstances and linguistic creolizations could have given rise to the Proto-Indo-European language which seems to have arisen more or less in the vicinity where Danubian farmers and Uralic populations were interacting at the time.

Modern genetic and linguistic and archaeological evidence largely rule out any significant eastbound linguistic influence on the Persians or Europeans, with the possible exception of the Uralic languages (a matter of considerably scholarly disagreement), until the historic era. Likewise, there is really no evidence to suggest that any of the Altic languages, East Asian languages, Tibetan-Burmese languages, or Southeast Asian languages have origins in the West. A more remote possibility, that doesn't really cross the East-West linguistic line, is that a Harappan presence in the B.M.A.C. area may have influenced the Indo-European or Uralic or some of the Caucuasian languages. The Dravidian languages, whose South Asian origins around 2500 B.C.E. are obscure and contested, and the Na-Dene languages of the Americas which have linguistic ties to the Yenesian languages (presumably from 14,000 or more years ago), are the only notable exceptions in which Eastern languages may have plausible strong pre-historic roots in the West.

The Basque, whose extremely high levels of lactose tolerance not found in the ancient DNA of megalithic farmers (that persists today in populations such as the Gascons of Southern France), who did not really participate in the megalithic culture, probably had significant genetic origins in dairy farmers, who probably arrived on the scene later than the megalithic farmers, but clearly were present before the earliest Indo-European Celts arrived in Iberia. Basque DNA, as indicated by mtDNA signatures like haplogroups V and certain ancient U haplogroups like Ub5, probably assimiliated, as did other French and Iberian populations near the Franco-Cantabrian refugia, largers share of hunter-gather populations (particularly maternally) than other populations of Europe. But, I find it doubtful that the language or culture have pre-Neolithic Iberian roots. How they got there is even less clear than when they probably arrived as a cultural entity (even if they an ancesteral component with significant deeper genetic roots). The Vasconic substrate clearly once had a larger geographic range than the Basque language does today, and may have even extended to Sardina, but its exact geographic extent is unclear.

Unless place names associated with a Vasconic substrate, which in its original formulation encompasses more or less the entire megalithic cultural region, were actually megalithic culture place names, the lack of identity between the Basque culture and the megalithic one may imply that the geographic extent of the Vasconic substrate may have been fairly narrow, or that Basque language family languages are recipients, rather than sources of Vasconic place names (i.e. toponymy and hydronymy) and substrate characteristics (such as base twenty number systems) from the prior megalithic culture of the larger region. Alternately, the features could have separate common origins in an Anatolian proto-language shared by the Greater Hurrian languages or some of the unattested major European branches of them. (Any megalithic culture, for example, may have had a language remotely derivative of a Cardial pottery culture.) The apparent regional substrate influences seem to be real, but German linguist Theo Vennemann's attribution of them to an originally Basque source, and his alternate somewhat more plausible hypothesis that the Atlantic megalithic culture substrate may have been para-Semitic, perhaps through the Phoenicians, have not received wide acceptance and are a stretch, at best. An alternative to either of these hypotheses would be that the linguistic commonalities have roots in ideosyncratic elements of a Celtic substrate which also coincides fairly closely with the region he identified (but fails to explain how these traits could end up in Basque regions as well).

There is definitely an Indo-European layer, and possible two or three in some places, representing Celts, Romans and Germanic populations, for example, in parts of Northern Europe, and pre-Slavic and Slavic populatios in Eastern Europe. These layers have considerable archaeology, strong remnants in existing linguistic populations as they are the "top" or "near top" layer of ethnogenesis, and often, some degree of written history to elucidate them.

There is an "indigineous" Northern European fishing population associated with the Comb Ceramic peoples (possible from the epipaleolithic era, which is, of course, later after the Last Glacial Maximum of 20,000 years ago) associated with the Uralic linguistic group admixed somewhat with possible repopulating Southern refugia populations and circumpolar elements at the Northeastern fringe of Europe. Realistically, Uralic is probably closer in age as a language to Indo-European, perhaps six thousand years give or take.

There are probably some places in Europe, in addition to Basque country and Tuscanny and the Aegean basin, where there was probably at least one Enolithic or Bronze Age non-Indo-European population between the first wave Neolithic farmers and the Indo-Europeans that was not strongly in continuity with either, such as the Minoans and possibly the entire Aegean basin, but it isn't entirely clear where this happened. We must look mostly to archaeology for these answers and seem to be the exception rather than the rule outside the Mediterrean basin.

Finally, of course, there are population and linguistic movements that are historically documented in the last two thousand years, such as the Jewish diaspora, the Gypsies, the Moors in Iberia, and the 20th century immigrant populations of Europe, mostly from former colonies of European powers.

Magnetic Moment Of Proton Small, Not Known With Much Accuracy

[T]he magnetic moment of the proton is 660 times smaller than that of the electron, which means that it is considerably harder to detect. . . . The magnetic moment of the anti-proton is currently only known to three decimal places.

From here.

A five year old experiment in Germany has just managed, for the first time, to directly measure the spin of a single proton, and provides a mechanism to measure the magnetic moment of individual protons and anti-protons with much greater precision in the near future at a tiny fraction of the cost of big budget experiments like the LHC. These experiments allow more accurate comparisons of the proton and anti-proton constants, to determine if they truly observe CP symmetry and offer a different methodology than prior experiments which have relied on statistical analysis of the behavior of large groups of protons or anti-protons.

Nobody really expects any surprises in these measurements. There is every reason to believe that the magnetic moments of the proton and anti-proton will be identical, and the values currently known to three significant digits are unlikely to be seriously nudged. But, greater precision in a measurement of one of the most common parts of the background that must be subtracted away to determine what more interesting quantum physics are going on in experiments will make it easier to observe new physics elsewhere with the same experiments (or even when looking at past experimental results). These constants help to set constants of QCD that have wide applicability, and the inaccuracies in these measurements limit the accuracy of theoretical QCD predictions generally.

More accurate measurements may also narrow the range of beyond the Standard Model physics, because a great many otherwise plausible extensions of the Standard Model incorrectly model proton behavior. The most obvious defect in these theories is that a large class of them generically predict proton decay, something that has never been observed, at rates far greater than are consistent with experimental limits on its frequency which are consistent with a half-life with an order of magnitude that is approaching the fourteen billion year age of the universe. But, if precision magnetic moment data were available, that would provide another way to identify extensions of the Standard Model that must be incorrect because they incorrectly model the proton, which is the most common form of baryonic matter, for which it is usually relatively easy to derive a prediction directly from the theory.

Tuesday, June 21, 2011

Coming Attractions in Physics

There have been several "false alarms" this year with data showing beyond the Standard Model results from experiments only to be promptly contradicted with additional data or other experiments.

Make or break point for Higgs should be in time for Oscars

But, at the rate the Large Hadron Collider is going, we can expect the big event of big events for high energy physics within the next six months. The Standard Model Higgs boson should be either discovered or ruled out by then. We should know if there is a Higgs before we learn who the best actor was for 2011. Finding a Standard Model Higgs boson would complete the Standard Model's predictions, while not finding it would open up a whole new can of worms as theorists scramble to find the most plausible alternative.

The Higgs, recall, is a theoretical particle that imparts mass to the massive particles in the Standard Model (and also has some W particle-like transformative effects that blend different quantum components of ordinary particles), with zero intrinsic spin, a significant vaccuum expection value (something that is zero for almost all other particles in almost all places), has no charge, interacts via the weak force, and has a mass on the order of 120 GeV/c^2 (the exact potential mass range varies from month to month).

Key experiment driving SUSY particle mass predictions may be wrong

Another interesting paper makes an contribution to the long standing effort to confirm or deny the extension of the Standard Model called supersymmetry (SUSY for short) which is a necessary component of any string theory.

There are lots of moving parts in SUSY, but most versions of it have predicted at least one particle (the "lightest supersymmetric particle") to have a mass of 1 TeV or less, which is bad news for SUSY fans because LHC has largely ruled this out for all but one candidate particle and has ruled out that candidate particle for masses of less than 750 GeV and closing. But, the theoretical "preference of the global fits for light superparticle masses is driven by one measurement: the long standing 3 sigma excess in the muon anomalous magnetic moment." (See, e.g., here (2008), here (2007), here (2003), and with an early version that seems to impose mass limits long since exceeded here (2001).)

This gap between the Standard Model prediction and the experimental result was big news in 2001. The new paper suggests that the apparent excess of the experimental value of the muon anomalous magnetic moment ("muon g-2") over the theoretically predicted value in the Standard Model is a product of inaccurate theoretical calculations, which, when calculated properly confirm the Standard Model prediction. If you look at the raw data this is less surprising, it doesn't take a huge nudge in the theoretical value (which in turn depends upon other experimentally measured quantities) to make a big difference in the discrepency, which is on the order of one part per million.

The experimental result from 2001 is aμ+ = 11659202(14)(6)×10^-10 (1.3 ppm).

The current theoretical value from the standard model from 2001 is aμ(SM) = 11659159.6(6.7)×10^-10 (0.57 ppm).

The difference, aμ(exp)-aμ(SM) = 43(16)×10^-10.

A 2006 experiment found a discrepency of 2.2 to 2.7 standard deviations and included theoretical uncertainty of about the same order of magnitude at the experimental uncertainty. Concerns that inaccuricies theoretical estimate were the source of the discrepency were already being raised in 2004 and repeated with more force indicating that the discrepency could be as small as one sigma with certain experiments used to set Standard Model constants in a 2009 publication. On the other hand, the Standard Model prediction is one of ongoing research with a 2007 estimate of it arguing that the discrepency was actually understated, and a 2009 paper came to a similar conclusion.

If the new calculation by a novel method is correct, the gap between the theoretical prediction of the Standard Model and the experiment result would be roughly 1% of the previous estimate - bringing it from a 2-3 sigma gap to a 0.02 to 0.03 sigma gap, which would normally be treated as an extremely clear confirmation of the theory by the experiment.

The good news for SUSY fans is that such an error would make higher masses for the lighter supersymmetric particles plausible, thereby preventing SUSY (and with it string theory) from being ruled out by LHC experiments in the near future due to an absence of light supersymmetric particles (concerns that a large muon g-2 were inconsistent with SUSY were being raised years before the LHC came online).

The bad news for SUSY fans is that the fewer deviations from the Standard Model we observe, the less we have an empirical data driven need for any kind of Standard Model extension. While a value for muon g-2 that is too high implies that SUSY particles are too light to be consistent with experiment, a value for muon g-2 that is extremely low suggests that SUSY particles may be predicted to be too heavy to make sense given other experimental constraints on the model.

Low energy QCD calculations close to confirmation

Preliminary results from the RHIC experiment tend to confirm a "phase change" in low energy quark behavior as a result of the strong force equations at a critical boundary that is a function of temperature and baryon chemical potential. Up until you hit the critical boundary, you expect norm "hadrons" made of quarks collected together in lumps like protons, and neutrons and mesons. Beyond it, you expect a quark-gluon plasma which should look different in the experiment (or perhaps a "color superconductor" in a special part of the beyond the boundary region of parameter space found in places like neutron stars that isn't within the scope of these experiements).

But, the preliminary experimental results from RHIC have an error bar too wide to confirm the results because there is too much statistical uncertainty in the small data set collected to date. Enough data to confirm or deny the QCD equation predictions should be available from this experiment by year end. If the predicted results are still observed when the data are all in, it will be a major confirmation that the QCD equations are experimentally accurate, and that the two camps of people doing the insanely difficult math that the QCD equations imply (the discrete mathematicians who use a lattice approximation to exactly calculate the full equations at discrete points, and the perturbative mathematicians who start with simplified QCD equations and then estimate how much different the real results are from the predicted ones used advanced calculus methods that are continuous) are on the right track. Both camps predicted essentially the same critical point in recent theoretical work.

Now, "experiments confirm that forty year old equations still work" won't make the same kind of headlines that the Higgs will, but, it still matters quite a bit because QCD has some of the biggest holes in the program of experimental confirmation of the Standard Model, in part, because it is so hard to figure out what the Standard Model predicts because the math is so difficult and in part because the experiments themselves aren't easy to devise or cheap to conduct.

Proving a theoretical result like this is a bit like flying completely blind from New York to Los Angeles and coming to a safe landing anyway. There is a very long chain of mathematical reasoning that goes from the experiments that caused us to propose the QCD equations of the Standard Model (which govern the forces that hold atomic nuclei together) to this experimental confirm of those equations where almost none of the experimental conditions that the equations were designed in are similar.

Even more importantly, the phase change that RHIC seems to be observing and that is predicted is the first real evidence of chiral symmetry breaking in QCD. There are natural terms in the QCD equations that were used to make these predictions that suggest that the strong force distinguishes between particles with left handed spin, and particles with right handed spin, something that has so far been observed only in weak force interactions. But, so far, no distinction has been observed and instead we have seen "chiral symmetry" in the strong force. This has cast doubt on whether the chiral symmetry breaking term should even be in the Standard Model QCD equations.

But, if this experiment's implications are correct, the chiral term does belong in the QCD equations and hasn't been observed to date because we haven't observed quarks and gluons in conditions where term has the effect of breaking the chiral symmetry. Also, if chiral symmetry breaking is observed, it may shed light on the "strong CP problem," one of the big unsolved questions in fundamental physics (the absence of CP violations in the strong force).

This result are also important because they establish that theoretical physicists are finally reaching a point where they are able to solve equations that have to date been a question mark. Accurate QCD calculations are the background against which all other high energy physics phenomena are calculated, and the more confidence that we can have in their accuracy, there more statistical significance experimental results, past and present, have in relation to the theoretical predictions.

The muon g-2 reanalysis mentioned above is just one example of the kind of result that we can expect to appear over and over again in the entire range of quantum physics phenomenology as the theoretical prediction calculations grow more precise and reliable. Old results that seemed to show a discrepency between experiment and theory may be reconciled in some cases, and anomalous results that weren't statistically significant enough given the undercertainty in the underlying theoretical prediction in the past may rise to statistically significant levels that call for further investigation in other cases.

Thursday, June 16, 2011

Replacement As A Human Population Norm

The genetics of Andaman Islanders (off the coast of Burma), together with paleoclimate data, pretty strongly suggest that they were isolated from other human populations for about 20,000 years and fit more or less within a range of genetic variation that still exists today in Northeast India. Only a handful of human populations have been isolated that long, and most have seen massive waves of population replacement, sometimes multiple times, since the introduction of agriculture.

The observation that the only population in Europe that doesn't speak an Indo-European or Uralic language, the Basque, are the most lactose tolerant population in the world (suggesting their ethnogenesis probably took place sometime after a selective effect that arose after the development of dairy farming allowed the trait to reach fixation in this population), likewise dispells the notion that any large current population of Europe draws much of its ancestry from Upper Paleolithic Europeans.

Only a handful of modern populations have a strong likelihood of having more or less uninterrupted descent from the pre-Last Glacial Maximum populations of the places that they live today. For example, pre-LGM (ca. 20,000 years ago), the Americas and much of Oceania were uninhabited. Most, but probably not all, Tibetans have genetic origins in East Asia at sometime since the LGM.

The Bantu populations of Southern and Eastern Africa are more recent arrivals, as is the population of Madagascar. Before then, Southern Africans looked like modern Bushmen, they weren't racially the same as what we now call "black" Africans. And, Africa's West Africans and Nilo-Saharans are likewise populations that are probably predominantly products of migrations and population expansions within the last 20,000 years.

There are very strong indications from multiple lines of evidence that all modern humans have common origins in a single human community within the last 250,000 years or so somewhere in Africa, and the similarly strong indications that all non-Africans probably have origins in one (or at most two or three) main migration events sometime in the last 100,000 years. But, we can draw only weak conclusions about the first 80,000 years of our existence as Eurasian hunters and gatherers from the genetic landscape of today. Indeed, it is extremly challenging simply to discern the outlines of the first 7,500 years of our pre-history from the time that agriculture and domesticated animals other than dogs arose until written records began to recount events with any regularity.

The latest discoveries from ancient DNA and archaeology and population genetics increasingly suggest that in Europe, at least, there isn't even all that much genetic continuity between the early Neolithic era and the present. In most of Europe, there have been at least one or two major waves of population near replacement since then. Large swaths of Europe have their genetic roots predominantly in Indo-European migrations and expansions that have taken place since the Bronze Age (in other words, since about 2,500 BCE).

Of course, in some places, the current population traces its roots where it lives now much less far in the past. The vast majority of North Americans predominantly have ancestors who arrived in the North America within the last five hundred years, and the median ancestor of a contemporary North American probably arrived within the last century and a half or so. Northern Thailand experience a major population replacement in the 13th century. Northern Japan experienced a major demographic shift in the last thousand years, with Hokkaido experiencing that shift in the last few hundred years. New Zealand has only been inhabited for about a thousand years and has experienced 80% to 90% population replacement in the last couple of centuries. Population replacement was even more complete in the last couple of centuries in Australia. Texas, California and much of the rest of the Western United States have gone from being populated almost entirely by people of Iberian and Native American descent in 1800, to being populated predominantly by people descended from neither of those populations today. Jews were a tiny proportion of the population of Israel a century ago. Most of the Han Chinese people in Western China have roots there only in the last seventy years, and most of the Caucasians in Eastern Russia have roots there within the last two centuries. The white and colored populations of Southern Africa didn't exist when Columbus sailed across the Atlantic. Large shares of the population in Kuwait and Saudi Arabia and the United Arab Emirates are non-citizen foreign workers. The vast majority of Alaskans have roots there only in the last seventy years.

While Young Earth Creationists are profoundly wrong about the age of our world, of our species and our life on earth, most of our cultural legacies can be traced to the Holocene era, which starts roughly when the Young Earth Creationists claim that the world came into being. The most widely accepted estimate for the origin of the Indo-European language family that includes languages from Gaelic to English to Greek to Persian to Hindi is about 6,000 years give or take a few centuries. Sumerian, the most widely spoken language of Iraq and the first to be recorded in writing, is a dead language, as are all other languages that can be definitely said to belong to the same language family. The pygmy languages probably died sometime in the Bantu expansion. The languages spoken in Pakistan's civilization for thousands of years prior to the arrival of Indo-European languages are probably lost and completely dead now. The Afro-Asiatic languages that are still spoken today probably have a common origin no older than farming, and Arabic, the overwhelmingly dominant member of the linguistic macro-family was spoken by no one but some minor tribes of herders in the Arabian desert as recently as sixteen hundred years ago. Twenty-five hundred years ago, no one in Japan spoke Japanese. Two thousand years ago, no one in Turkey spoke any language even remotely related to Turkish.

The oldest of the world's major organized religions that is still practiced today, Hinduism, is probably about 4,500 years old. Polytheistic religions that were dominant from England to Egypt to Finland just two thousand years ago have only a tiny number of practioners and most of those practitioners are neo-pagans are who resurrected those faiths after more than a millenium in which those faiths had vanished from old myths and images starting in the 18th or 19th century.

Foods that now define nations, like potatoes in Ireland, spicy kim-chee in Korea, and black tea in England were never consumed in those respective countries five hundred years ago. Bananas never found their way into the diet of African monkeys until human mariners brought them there around the time of the Bantu expansion or later. The Kumara that is central to the Maori diet in New Zealand and in much of the rest of Oceania somehow made its way from South America (probably in a single sea voyage) in roughly the last millenium.

While we have approximately 5500 years of written history for at least parts of the world, mass produced books are only 500 years old.

Modern political and economic institutions are even younger. There is no place on earth that has been continously a democracy for a thousand years. All but a few of the world's democracies were democratic two hundred and fifty years ago, and even in those places the franchise was much narrower than it is today. Two hundred years ago there was almost no where in the world that women were allowed to vote. When I was born, about 95% of law students were men, now it is just over 50%. All but a few of the current regimes in Europe have been interrupted in the last seventy years. Slavery has gone from being an international norm to an abberation in two hundred years. The use of the death penalty has declined dramatically in the last two or three generations. Marriages that aren't arranged have been the norm for less than a couple of centuries in most of the world, and in many places less than a century.

We are becoming aware of our most ancient roots just as the last traces of them are vanishing.

You Get More From Your Parents Than Parenting

Lots of people are raised for substantial parts of their lives by people whom they are not genetically related to, and a new study of Korean adoptees from the 1950s and 1960s has revealed once again that a rather surprisingly large share of the way that kids turn out is congenital rather than a product of the way that they were raised.

Having a college educated mother increases an adoptee’s probability of graduating from college by 7 percentage points, but raises a biological child’s probability of graduating from college by 26 percentage points. In contrast, transmission of drinking and smoking behavior from parents to children is as strong for adoptees as for non-adoptees. For height, obesity, and income, transmission coefficients are significantly higher for non-adoptees than for adoptees. In this sample, sibling gender composition does not appear to affect adoptee outcomes nor does the mix of adoptee siblings versus biological siblings.

Factors like religious affiliation and linguistic accent are also very strongly cultural. Nobody is born Christian or Buddhist, or speaking Spanish or English. Genetics may influence you attitude towards religion, or your likelihood of having a learning disability related to reading, but it won't determine the content of your religious beliefs or the language that you will learn.

But, parental income at the time of adoption has virtually no effect on adopted child income. Parental education does have a modest effect on adopted child educational level (parents who went to graduate school have adopted kids with half a year more of education than those who merely graduated from high school), but the effect is really strong only for parents who don't have at least a high school diploma (those kids get dragged down). In contrast, parental income and education have a rather pronounced effect on the the incomes and educational levels of biological children suggesting that these outcomes are mediated by factors like hereditary IQ and personality effects.

This doesn't necessarily mean that your parents alone are your destiny. Quite extensive studies have shown that there is a fairly wide range of stable differences in all sorts of traits between even full blooded siblings on factors from IQ to personality and that those differences impact life outcomes. Almost no intelligence or personality or mental health traits are 100% hereditary or even much more than 85% hereditary, and most hover at the 50% level or less.

There is also a fair amount of evidence to show that really bad parenting and early childhood deprivations or physical traumas can screw anyone up no matter how much potential that person may have had at birth. Genuine poverty, malnutrition, lead poisoning, prolonged isolation, and abuse are all bad for kids no matter how promising they are (although there are even genes that govern how well kids can cope with some of these adversities, a trait sometimes described as resilience).

But, given the intense amount of effort the parents put into deciding precisely how to raise our children, parenting choices make less of a difference than one would intuitively expect. Princes raised by peasants really do generally grow up to be princes, royal bastard are going to tend to outperform their ordinary siblings, and kids raised in circumstances far more favorable than those they were born in because they are adopted generally underachieve relative to the biological children of their adoptive parents and have less in common with their siblings than you would expect from a shared upbringing. It may have a ring to the monarchist propaganda that Disney likes to produce, but there is truth to it. The myth of Achilles, who was a prince raised by farmer parents as their own who rises to prominence, is closer to real life than the Prince and the Pauper.

Indeed, there are at least one or two studies out there that show that decent parenting from just about anyone is fine. A good step-parent or adoptive parent or extended family member in lieu of a parent can raise you well enough to reach essentially the same potential you could have if raised by a biological parent - or better if a biological parent's exceptionally bad parenting was factor that could have dragged you down.

It is hardly surprising that assortive mating should strength social class divides. If people who have what society rewards have kids with other people who have the same traits, and people who lack that have kids with other people who lack that, we expect that there kids are more likely to reproduce their status than in a society where couples form at random or are deliberately unequal in traits that society rewards, which will tend to produce more variability between siblings and more averaging out.

More paradoxically, each generation that society is meritocratic should strength class divideds in future generations. Some people from modest beginnings will always be more talented than their parents, and some people with talented parents will always have less of what made their talents successful. Regression towards the mean is to be expected, and the less talent matters the less talent will be associated with social class and the more vulnerable the social class system will be to being upset by talented people born in a lower socio-economic class usurping less talented people born to privilege.

By all accounts, American marriages are more assortive than they used to be, and we have had roughly two full successive generations of a relatively meritocratic society. The longer this continues, the more stark social class divisions can be expected to become, with really no obvious limits. A few centuries of carefully preserved meritocracy and assortive mating should paradoxically greatly reduce social class mobility and make the gradations within social classes more fine, to the extent that social class divisions are a product of individual personal traits rather than the nature of the slots the arise from our current technology and economic system. A hunter-gather society, for example, can support only so much social class stratification.

Monday, June 13, 2011

Fundamental Physics: The Medium Term View

There is a lot that we know in fundamental physics - which is to say the scientific endeavor of determining the most basic sets of laws of physics from which all other scientific phenomena can be derived, at least in principal, if not in practice. Most of that is captures in two basic theoretical constructs: Einstein's law of general relativity, and the Standard Model. General relativity has emerged remarkably in tact after about a century. The Standard Model has undergone some minor renovations over the last half century, most recently imparting mass to neutrinos, but has also been remarkably robust in the face of precision tests.

For all of that, most physicists do not believe that we have learned all that there is to learn, and that there are theories of fundamental physics yet to be discovered.

General relativity and the Standard Model are not perfectly compatible at a theoretical level, even though their inconsistencies generally arise in unobservable contexts. There is not yet a widely accepted and empirically supported theory of quantum gravity.

We have equations for quantum chromodynamics (strong force interactions between quarks), but are still somewhat fuzzy about what those equations imply. Numerical models based upon these equations currently surpass our ability to confirm their predictions experimentally and there is not complete consensus regarding how to go about making numerical predictions from these equations (which are too hard mathematically to computer exactly and directly from the equations).

Our theories regarding dark matter and dark energy phenomena are still works in progress.

The weak force shows greater charge-parity violations than we would expect, while the strong force shows none experimentally despite equation terms that could naturally provide for them.

We observe differences in properties between muonic hydrogen spectrums and ordinary hydrogen spectrums, but it isn't really clear why these occur.

One Standard Model particle, the Higgs boson (there may be more than one kind of them), has not yet been discovered (although a definitive determination regarding its existence is very likely within the next couple of years).

We haven't definitely ruled out a whole menagerie of theoretically proposed particles, and if dark matter is a result of some kind of matter not yet directly observed we need at least one more than we've observed to make the laws of the universe complete.

Efforts to come up with any more profound reason for the many constants in the Standard Model are so far without a clear winner.

With the large hadron collider, and a number of lower profile fundamental physics experiments, up and running, we are receiving an immense amount of new data. But, we have failed to see anything that strongly favors extensions of the Standard Model such as supersymmetry, string theory, technicolor, preon theories, or loop quantum gravity. Neutrino experiments are hinting that there may be more than three flavors of neutrinos. There are perhaps half a dozen unexplained results from high energy physics experiments, but none definitive or well understood theoretically.

False alarms seem to be common, mostly because error estimates in physics experiments ignore "unknown unknowns" that turn out to be pretty important sometimes.

While it seems more and more clear that somewhere in all the smoke of phenomena that don't quite match theoretical expectations there must be fire, the constraints on any extensions of the Standard Model or General Relativity are tightening each year with new results. We don't have the exact laws of the universe on the books, but we are close. The Standard Model needs tweaking, but not much, even in highly eosteric circumstances. General Relativity is at least a very good classical approximation of how the universe behaves. The flaws in these theories are in domains that are hard to measure and hence don't necessarily have much practical application.

My own intuition is that we will find less, rather than more, in the next few years. Far more theories for extensions of the Standard Model will be ruled out than established. The possibility that we will empirically rule out all Standard Model Higgs boson possibilities is real. The possibility that we will still see no supersymmetric particles or phenomena is great.

Tuesday, June 7, 2011

What Will Faith Look Like In The Late 21st Century?

Surveys show that 40% of Americans claim to be young earth creationists. But, it is increasingly obvious that viewing the Bible, particularly Genesis, as a literally accurate account is untenable. It is possible to reconcile the two by describing the parts of the Bible that scientifically inaccurate, particularly in Genesis, as figurative language and by recognizing that the cosmology and origins story of the Bible don't have to be central to the "Good News" of Christian theology. One can have original sin, for example, in a theology that describes the story of Adam and Eve as a mere heuristic to help people understand how deep seeded man's sinfulness is rather than as a specific event that happened and metaphysically tainted humanity. Indeed, Biblical literalism is largely a doctrine of a subset of American Christians and the Christians who have their religious roots in American missionary efforts.

The deeper problem, however, is that science and rational enlightenment more generally, is eating away at the larger premise of a Christian worldview. We don't have the same needs that 1st century Levantines and Romans did. Rather than looking for faith healers who exorcise demons and lay on hands to bring about miraculous cures, we more timidly hope for some supernatural force to tilt the balance of fate in our favor amidst the uncertainties that come even with modern medicine. We no longer need an origins story. We have other ways of evaluating what makes the most sensible diet. Our society cares a lot about how secular authorities define marriage and family, while we are almost indifferent to religious pronouncements about it - if we don't like them, we'll find another prophet to follow. The notion that avenging angels sent by God wreck havoc on wrong doers seems absurd to a typical modern person.

It isn't that we are a society without spiritual need. We still must cope with grief, failure, heartbreak and defeat. We still must make sense of affluence and obligation, our obligations to our parents and our obligations to children. We still need a sense of right and wrong, a way of making something in life sacred, community ways of celebrating important moments and bonding ourselves to each other, ways of uniting for social justice and the common good, leadership that is accountable to something less transient than the latest opinion polls and campaign contributors. We need to make sense of our marriages, of our moral struggles, of the meaning of life and of our place in the world.

It just isn't clear than any of the currently well established religions can provide convincing answers to these questions any more. Nature abhors a vacuum. Particularly in Europe, where secularism has gone far to supplanting a historical establishment Christianity, will some new organized system of faith that is at least para-religious step in to fill the void?

Friday, June 3, 2011

How are simple root words invented?

There are multiple means by which languages acquire new words, a process called "word formation." We borrow words from other languages (for example, "amok" from Indonesian or "manga" from Japanese). We combine words and sometimes then streamline the resulting combination (for example, "Internet" and ultimately "the Net"). We turn acronyms into words (for example, "FUBAR", from "Fucked Up Beyond All Repair."). We attach new meanings to old words (for example, "gay" to mean homosexual, "hacking" to mean computer mischief, or "frag" to mean killing a superior office (derived from fragmentation grenade, a tool used at the time the term was coined to carry out the deed of killing a superior officer to which it refers)).

Sometimes we create new words entirely from whole cloth, as subtype of neologism. Heinlein introduced "grok" meaning "to intuitively and fully understand" in one of his books. The Battlestar Galactic screenwriters invented "frak", a swear word comparable in meaning to "fuck" (although arguably derive of it in much the way that "dang" is derivative of "damn"). The term "robots" was "introduced to the public by Czech writer Karel Čapek in his play R.U.R. (Rossum's Universal Robots), which premiered in 1921." Lewis Carroll also created many natural sounding words of this kind, although few have entered general usage. J.K. Rawling brought "muggle" into the lexicon and the term is now used in a more general sense than it was in her books in a sense comparable to "layman" or "unenlightened" or "ordinary people". But, the simple, created out of whole cloth new root words are a pretty small part of the total additions to the lexicon in any given decade. Under what conditions does this happen?

The examples I've provided were creations of fiction authors whose works had loyal followings and who were intentionally trying to create an exotic feel of mild foreigness. They also followed linguistic rules of English related to joining phonemes into words (i.e. they are initially logatomes). They sound like natural simple Anglo-Saxon words.

Most new words also seem to arise in subcultures where they can be used in conversation among a smaller group of people more likely to know the novel word and with a social incentive to identify themselves with the group of people who know and use the word, before being disseminated into the larger culture, rather than arising diffusely.

Of course, there are other ways that words arive. "Googol" was a number named "in 1938 by 9-year-old Milton Sirotta (1929–1981), nephew of American mathematician Edward Kasner. Kasner popularized the concept in his book Mathematics and the Imagination (1940)." Quark was a nonce word used by James Joyce in Finnegan's Wake before it was adopted by Murray Gell-Mann is a physics term. The term meme was coined by Richard Dawkins (in analogy to "gene" from the ancient Greek mimeme) in his book, The Selfish Gene. Indeed, the sciences may be a particularly fruitful area for new word creation.

How often do these kinds of words enter the general lexicon in absolute terms and relative to other kinds of words? Do they arise in situations other than intentional speculative fiction, and if so when? Do they have any more or less staying power in the language than other new words? How long does it take for the people who use these words to cease to know their origins? Do these words generally refer to concepts that could previously be described only with multiple words or not at all, or do they generally replicate the meaning of single words that already exist? Is there anything inherent in the word itself that distinguishes those that enter general use after an attempt is made to introduce them from those that don't?

A related issue is how often new concepts that aren't expressed by any single word in our language (also known as lexical gaps) arise, and how common are they?

There are certainly cases where this is possible, even a mature language. New things are invented that must have nouns to describe them. French has the word "chez" which means "the home of" and has parallels in other romance languages (e.g. Spanish "casa", that is absent in simple one word form from English. English has stumbles over a gender neutral term third person singular pronoun referring to a human being equivalent to "him" or "her" although there are competing proposals for ways of dealing with it (using the word "one" for that purpose has been proposed at least since 1770 by Robert Baker, but has never gained universal acceptance in day to day language since it comes across as too formal, while using the word "they" in the singular has fairly wide acceptance in casual speech but is usually considered a grammatical error in formal speech), and also lacks a consensus way across dialects to distinguish between the second person singular ("you") and the second person plural ("you guys" or "y'all"). English lacks a single word that captures in a gender neutral way the phrase "significant other" although "partner" is increasingly being appropriated for that purpose. Why don't new words swiftly get invented and widely adopted even when the need for them is widely known? How many concepts are there out there that are longing for simple root words to describe them that instead linger like high school girls hoping to be asked out to the prom? While the "no word to describe it" in this language myth is greatly overused by journalists, certainly there are cases when it is true.

And, sometimes, elegance of expression does matter. People who know short, logical Chinese number words are better at memorizing and manipulating long numbers than people who know the English equivalents. It is easier to keep accounts with Arabic numerals than Roman numerals. If physicists had been forced to use Newton's notation to do calculus instead of the notation of Leibniz, man would probably never have made it to the moon. People with larger vocabularies are more successful in life, in part, perhaps because they can better match words to the meaning that they intend.

Also interesting is the question of why some languages, for example, Yiddish, have produced many words that have been comfortably borrowed into ideomatic English, while other languages that have many people familiar with them do not, or do not sound as natural. For example, Yiddish words (perhaps because they are fit to a Germanic language) tend to sound more natural in English than words borrowed from Greek.