Scientific Conference Shenanigans

The Pre-Columbian Pacific Coast

Here's a map of more than 6000 contact-era Native American Villages on the West Coast that were recorded from written accounts or oral traditions. 

A Global Map Of The Last Glacial Maximum (And Dingos)

The Last Glacial Maximum land bridge in Southeast Asia (ca. 18,000-20,000 years ago) was not the source of dingos in Australia, although this land bridge may have facilitated the migration of modern humans who led to the extinction of relict archaic hominins to the west of the Wallace Line in what is now island Southeast Asia.

The Sahul Shelf and the Sunda Shelf during the past 12,000 years: Tasmania separated from the mainland 12,000 ybp, and New Guinea separated from the mainland 6,500–8,500 ybp.

It also turns out that recent discoveries have estimated that the arrival of the dingo (Australia's native dogs) in Australia may have been much more recently than previously estimated, since the oldest dingo remains in Australia were previously misdated. The current dates are consistent with an arrival of dingos in Australia via Austronesian mariners. Wikipedia explains that:

The earliest known dingo remains, found in Western Australia, date to 3,450 years ago. Based on a comparison of modern dingoes with these early remains, dingo morphology has not changed over thousands of years. This suggests that no artificial selection has been applied over this period and that the dingo represents an early form of dog. They have lived, bred, and undergone natural selection in the wild, isolated from other dogs until the arrival of European settlers, resulting in a unique breed.

In 2020, an MDNA study of ancient dog remains from the Yellow River and Yangtze River basins of southern China showed that most of the ancient dogs fell within haplogroup A1b, as do the Australian dingoes and the pre-colonial dogs of the Pacific, but in low frequency in China today. The specimen from the Tianluoshan archaeological site, Zhejiang province dates to 7,000 YBP (years before present) and is basal to the entire haplogroup A1b lineage. The dogs belonging to this haplogroup were once widely distributed in southern China, then dispersed through Southeast Asia into New Guinea and Oceania, but were replaced in China by dogs of other lineages 2,000 YBP.

The oldest reliable date for dog remains found in mainland Southeast Asia is from Vietnam at 4,000 YBP, and in Island Southeast Asia from Timor-Leste at 3,000 YBP. In New Guinea, the earliest dog remains date to 2,500–2,300 YBP from Caution Bay near Port Moresby, but no ancient New Guinea singing dog remains have been found. The earliest dingo remains in the Torres Straits date to 2,100 YBP. 

The earliest dingo skeletal remains in Australia are estimated at 3,450 YBP from the Mandura Caves on the Nullarbor Plain, south-eastern Western Australia; 3,320 YBP from Woombah Midden near Woombah, New South Wales; and 3,170 YBP from Fromme's Landing on the Murray River near Mannum, South Australia. 

Dingo bone fragments were found in a rock shelter located at Mount Burr, South Australia, in a layer that was originally dated 7,000-8,500 YBP. Excavations later indicated that the levels had been disturbed, and the dingo remains "probably moved to an earlier level." 

The dating of these early Australian dingo fossils led to the widely held belief that dingoes first arrived in Australia 4,000 YBP and then took 500 years to disperse around the continent. However, the timing of these skeletal remains was based on the dating of the sediments in which they were discovered, and not the specimens themselves.

In 2018, the oldest skeletal bones from the Madura Caves were directly carbon dated between 3,348 and 3,081 YBP, providing firm evidence of the earliest dingo and that dingoes arrived later than had previously been proposed. The next-most reliable timing is based on desiccated flesh dated 2,200 YBP from Thylacine Hole, 110 km west of Eucla on the Nullarbor Plain, southeastern Western Australia. When dingoes first arrived, they would have been taken up by indigenous Australians, who then provided a network for their swift transfer around the continent. Based on the recorded distribution time for dogs across Tasmania and cats across Australia once indigenous Australians had acquired them, the dispersal of dingoes from their point of landing until they occupied continental Australia is proposed to have taken only 70 years. The red fox is estimated to have dispersed across the continent in only 60–80 years.

At the end of the last glacial maximum and the associated rise in sea levels, Tasmania became separated from the Australian mainland 12,000 YBP, and New Guinea 6,500–8,500 YBP by the inundation of the Sahul Shelf. Fossil remains in Australia date to around 3,500 YBP and no dingo remains have been uncovered in Tasmania, so the dingo is estimated to have arrived in Australia at a time between 3,500 and 12,000 YBP. To reach Australia through Island Southeast Asia even at the lowest sea level of the last glacial maximum, a journey of at least 50 kilometres (31 mi) over open sea between ancient Sunda and Sahul was necessary, so they must have accompanied humans on boats.

Some best estimates of Austronesian migration are as follows:

Suggested early migration route of early Austronesians into and out of Taiwan based on ancient and modern mtDNA data. This hypothesis assumes the Sino-Austronesian grouping, a minority view among linguists. (Ko et al., 2014).

Map showing the migration of the Austronesians from Taiwan. Indonesia is reached ca. 3500 years BP, and Papua New Guinea is reached ca. 3300 years BP.

There is no direct evidence of the involvement of Austronesian mariners bringing dingos to Australia, but they were the only sea faring people in the region at the time who could have made the trip beyond the line of sight over deep waters in that era, were engaged in seafaring in the region at just about the right time, had ties to Southern China where dingos probably originated, and dingos pretty much had to have arrived in Australia with people by boat, as opposed to without human intervention. 

The timing and location of the earliest Australian dingo remains also suggests an introduction from someplace in Indonesia to someplace west of Cape York in Australia, rather than from Papua New Guinea to Cape York, which would have involved the shortest overwater journey. This was a trip well within the maritime capabilities of the Austronesians of 3500 BP to 3300 BP.

An Old Specimen Of Homo Erectus

A new Homo Erectus specimen from Ethiopia confirms that this species of archaic hominin arose about 2 million years ago in Africa. This species went extinct around 100,000 years ago.

With new paleomagnetic dating results and some description of recently excavated material, Mussi and coworkers show that levels D, E, and F are between 2.02 million and 1.95 million years old. Most interesting is that level D includes what is now the earliest Acheulean assemblage in the world, and level E has produced the partial jaw of a very young Homo erectus individual. The Garba IVE jaw is now one of two earliest H. erectus individuals known anywhere, in a virtual tie with the DNH 134 cranial vault from Drimolen, South Africa.

From John Hawks.

Modern Human Introgression Into Neanderthal DNA

Altai Neanderthals had significant (6%) modern human admixture from admixture events as much as 250,000 years ago (at the very dawn of the modern human species). Thus, gene flow went both ways between Neanderthals and modern humans. These genes mostly reduced the selective fitness of the hybrid Neanderthals.

Neanderthal admixture in sub-Saharan Africans, meanwhile, is due to Eurasian back migration to Africa.

Highlights 

• Anatomically modern human-to-Neanderthal introgression occurred ∼250,000 years ago

• ∼6% of the Altai Neanderthal genome was inherited from anatomically modern humans

• Recent non-African admixture brought Neanderthal ancestry to some African groups

• Modern human alleles were deleterious to Neanderthals

Summary

Comparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. 

All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear. 

To better understand how these regions are distributed across sub-Saharan Africa, the source of their origin, and what their distribution within the genome tells us about early AMH and Neanderthal evolution, we analyzed a dataset of high-coverage, whole-genome sequences from 180 individuals from 12 diverse sub-Saharan African populations. 

In sub-Saharan African populations with non-sub-Saharan African ancestry, as much as 1% of their genomes can be attributed to Neanderthal sequence introduced by recent migration, and subsequent admixture, of AMH populations originating from the Levant and North Africa. 

However, most Neanderthal homologous regions in sub-Saharan African populations originate from migration of AMH populations from Africa to Eurasia ∼250 kya, and subsequent admixture with Neanderthals, resulting in ∼6% AMH ancestry in Neanderthals. These results indicate that there have been multiple migration events of AMHs out of Africa and that Neanderthal and AMH gene flow has been bi-directional. 

Observing that genomic regions where AMHs show a depletion of Neanderthal introgression are also regions where Neanderthal genomes show a depletion of AMH introgression points to deleterious interactions between introgressed variants and background genomes in both groups—a hallmark of incipient speciation.

Daniel N. Harris, et al., "Diverse African genomes reveal selection on ancient modern human introgressions in Neanderthals" Current Biology (October 13, 2023). DOI:https://doi.org/10.1016/j.cub.2023.09.066

A popular media discussion of the paper explains that:

[T]hey compared the modern human genomes to a genome belonging to a Neanderthal who lived approximately 120,000 years ago. For this comparison, the team developed a novel statistical method that allowed them to determine the origins of the Neanderthal-like DNA in these modern sub-Saharan populations, whether they were regions that Neanderthals inherited from modern humans or regions that modern humans inherited from Neanderthals and then brought back to Africa.

They found that all of the sub-Saharan populations contained Neanderthal-like DNA, indicating that this phenomenon is widespread. In most cases, this Neanderthal-like DNA originated from an ancient lineage of modern humans that passed their DNA on to Neanderthals when they migrated from Africa to Eurasia around 250,000 years ago. As a result of this modern human-Neanderthal interbreeding, approximately 6% of the Neanderthal genome was inherited from modern humans.

In some specific sub-Saharan populations, the researchers also found evidence of Neanderthal ancestry that was introduced to these populations when humans bearing Neanderthal genes migrated back into Africa. Neanderthal ancestry in these sub-Saharan populations ranged from 0 to 1.5%, and the highest levels were observed in the Amhara from Ethiopia and Fulani from Cameroon.

Columbus Day Considered

Christopher Columbus was a pretty horrible person, so I have no problem ceasing to honor him with a national holiday. But he was also a uniquely important historical person whom everyone should know about, and the well attested date of his arrival, in 1492 CE, should also be something that every educated person knows.

Columbus was not the first person to make contact with the Americas after the arrival and dispersal of the predominant Founding populations of the indigenous people of South America, Mesoamerica, and most of North America around 14,000 years ago from Beringia where these populations had an extended sojourn in their migration to the Americas from Northeast Asia. They arrived with dogs, but no other domesticated animals.

There was at least one small progenitor wave of modern humans that reached at least as far as New Mexico before them about 21,000 or more years ago (as recent research has confirmed this year from earlier less definitive data), but unlike the Founding population of the Americas (itself derived from a genetically homogeneous population of less than a thousand Beringians), they left few traces and had little, if any, demographic impact on the Founding population that came after them, or had only the most minimal, if any, ecological impact on the Americas. 

Columbus also arrived after the later arrival of two waves of migration from Siberia, one of which brought the ancestors of the Na-Dene people during what was the Bronze Age in Europe, and the second of which brought the ancestors of the Inuits during the European Middle Ages, both of whom were mostly limited to the Arctic and sub-Arctic regions of North America, except for a Na-Dene migration to what is now the American Southwest around 1000 CE plus or minus (in part from pressure to move caused by the ancestors of the Inuit people). The Na-Dene ultimately heavily integrated themselves into the local population descended from the Founding population of the Americas. The Inuits admixed some, but much less, with the pre-existing population of the North American Arctic and largely replaced a population of "Paleo-Eskimos" who derived from the same wave of ancestors as the Na-Dene in the North American Arctic.

A few villages of Vikings settled for a generation or two in what is now Eastern Canada ca. 1000 CE before dying out or leaving (and leaving almost no genetic trace in people who continued to live in the Americas). And, the Polynesians (and perhaps others) probably made contact with the Pacific Coast of South America and Central America several times in the time frame (generously estimated) of ca. 3000 BCE to 1500 CE, again without a huge impact on the Americas or the rest of the world and with only slight amounts of admixture.

But the contact that Christopher Columbus made with the Americas persisted and profoundly changed both the Americas and the rest of the world. He returned to Europe and then came back with more Europeans who aimed to conquer the New World (including many covert Sephardic Jews seeking a more hospitable future than they had in Iberia). 

Christopher Columbus's first contact led to a chain of events that resulted in the deaths of perhaps 90% of the indigenous population of the Americas (mostly due to the spread of European diseases like small pox and E. Coli, to which the people of the Americas had no immunity, at a time prior to the germ theory of disease, and only secondarily due to more concerted hostile actions taken by the European colonists towards the indigenous populations), led to the collapse of the Aztec and Inca civilizations at the hands of Spanish Conquistadors, brought syphilis to the Old World (especially Europe), brought horses to the Americas, led to the deforestation of much of North America, and brought crops native to the Americas including potatoes, maize, tomatoes, and hot chilis to the Old World (both Europe and Asia). Indirectly, this chain of events even led fairly directly to the Irish potato famine more than three centuries later.

His arrival started the chain of events that caused Spanish and Portuguese to become the dominant languages of South American, Central America, Mexico, and much of the Caribbean, in heavily admixed populations with mostly Iberian European male ancestry, and caused what became the United States and Canada to become mostly English and French speaking, where a policy of population replacement became the norm. Thousands of indigenous languages went extinct in this process. All but a few hundred of the rest of are now moribund or nearly so an declining. Those few hundred indigenous American languages that do survive are mostly minor secondary languages in their homelands now: only thirty-five have more than 100,000 speakers and just six have more than 1,000,000 speakers. 

In the U.S., Canada, and Greenland, the twelve most widely spoken are Navajo in the U.S. with about 170,000 speakers, followed by Cree in Canada with 96,000 speakers, Kalaallisut in Greenland with 57,000 speakers, Ojibwe in the U.S. and Canada with 48,000 speakers, Inuktituk in Canada with 39,475 speakers, Blackfoot in the U.S. and Canada with 34,394 speakers, Sioux in the United States with 25,000 speakers, O'odham in the U.S. and Mexico with 23,313 speakers, Yup'ik in the U.S. with 18,626 speakers, Western Apache in the U.S. with 14,012 speakers, Keresan in the U.S. with 13,073 speakers, and Chipewyan in the Canada with 11,325 speakers. Twenty-one more indigenous languages in this region have more than 1,000 speakers but less than 10,000. All twenty-three of the indigenous languages of the Americas with more speakers than Navajo are spoken outside this region (i.e., in Latin America).

But for Christopher Columbus's initiative to mount his expedition, similar events would have taken place eventually, anyway, but they might have taken place decades or even a century later in global history in different ways. A North America colonized along the Iberian model, for example, as much of the Western United States was at first, could have led to a very different human geography than what we see today. The eventual first lasting Old World contact might have even happened in a Trans-Pacific voyage from Asia, instead of across the Atlantic Ocean.

Linguistic Terminology

One of the big issues in classification, mostly a terminology question, is where to draw the line between two ways of speaking and writing being dialects v. different languages, in part, because it often has political connotations.

"language" has two meanings: a generalized, abstract sense that comprises all human speech and writing, and the officially recognized speech and writing of a nation / country / gens — a politically united group of people.

A topolect is the speech / writing of the people living in a certain place or area. It is geographically determined.

A dialect is a distinctive form / style / pronunciation / accent shared by two or more people. To qualify as the speaker of a particular dialect, one must possess a pattern of speech, a lect, that is intelligible to others who speak the same dialect. As we say in Mandarin, it's a question of whether what you speak is jiǎng dé tōng 講得通 ("mutually intelligible") or jiǎng bùtōng 講不通 ("mutually unintelligible"). If what two people are speaking is jiǎng bùtōng 講不通 ("mutually unintelligible"), then they're not speaking the same dialect.

Naturally, the dividing line between one dialect and another is not sharp. There is a blending, a gradation, a blurring between them. The same if true of languages on a larger scale. For example, I can understand close to a 100% of the speech of natives of Stark County, Ohio, but maybe only 75-80% of rapid speech from Vinton County in the south.

An idiolect is spoken by only one person. . . .

"Dialect" means so many radically different things, but also so many things that somewhat resemble each other, but are not really the same, that it is essentially useless for scientific purposes.

From Language Log.

Antimatter Falls Down

This shouldn't be a surprise to anyone, but experiments have now confirmed, at the ALPHA Experiment at CERN, that anti-matter does indeed fall down, which is to say that its mass-energy has the same gravitational "charge" as all other mass-energy, rather than "falling up" and having a repulsive gravitational reaction to ordinary mass-energy. A link to the peer reviewed paper in Nature, and it abstract can be found here. The abstract states:

Einstein’s general theory of relativity (GR), from 1915, remains the most successful description of gravitation. From the 1919 solar eclipse to the observation of gravitational waves, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the GR theory and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac’s theory appeared in 1928; the positron was observed in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter. In GR, the Weak Equivalence Principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive ‘antigravity’ is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

The WEP has recently been tested for matter in Earth orbit with a precision of order 10-15. Antimatter has hitherto resisted direct, ballistic tests of the WEP due to the lack of a stable, electrically neutral, test particle. Electromagnetic forces on charged antiparticles make direct measurements in the Earth’s gravitational field extremely challenging . The gravitational force on a proton at the Earth’s surface is equivalent to that from an electric field of about 10-7 Vm-1. The situation with magnetic fields is even more dire: a cryogenic antiproton at 10 K would experience gravity-level forces in a magnetic field of order 10-10 T. Controlling stray fields to this level to unmask gravity is daunting. Experiments have, however, shown that confined, oscillating, charged antimatter particles behave as expected when considered as clocks in a gravitational field. The abilities to produce and confine antihydrogen now allow us to employ stable, neutral anti-atoms in dynamic experiments where gravity should play a role. Early considerations and a more recent proof-of-principle experiment in 2013 illustrated this potential. We describe here the initial results of a purpose-built experiment designed to observe the direction and the magnitude of the gravitational force on neutral antimatter.

This Year's Nobel Prize In Physics

The 2023 Nobel Prize in physics has been awarded to a team of scientists who created a ground-breaking technique using lasers to understand the extremely rapid movements of electrons, which were previously thought impossible to follow.

Pierre Agostini, Ferenc Krausz and Anne L’Huillier “demonstrated a way to create extremely short pulses of light that can be used to measure the rapid processes in which electrons move or change energy,” the Nobel committee said when the prize was announced in Stockholm on Tuesday.

From CNN.

Usually, the Nobel Prize in Physics goes to someone who made a major theoretical advance. This year, however, the prize went to winners who developed a new experimental measurement technique.

This is fair. Experimentalists deserve their day in the sun and are absolutely critical to scientific advances in physics which are often under appreciated.

I wonder, however, if this choice doesn't also reflect ambivalence about which paths in the theoretical development of physics by physicists who are still alive and haven't yet received the prize, will turn out to be the right ones.

A New Anatolian Language, Called Kalasma, Is Discovered

Ancient Hittite records have revealed a previously unknown Anatolian language. It was probably spoken in or near the region indicated in red above. As the linked Language Log quotation of a press release from the researchers' institution explains:

An excavation in Turkey has brought to light an unknown Indo-European language. Professor Daniel Schwemer, an expert for the ancient near east from Würzburg, is involved in investigating the discovery.

The new language was discovered in the UNESCO World Heritage Site Boğazköy-Hattusha in north-central Turkey. This was once the capital of the Hittite Empire, one of the great powers of Western Asia during the Late Bronze Age (1650 to 1200 BC).

Excavations in Boğazköy-Hattusha have been going on for more than 100 years under the direction of the German Archaeological Institute. The site has been a UNESCO World Heritage Site since 1986; almost 30,000 clay tablets with cuneiform writing have been found there so far. These tablets, which were included in the UNESCO World Documentary Heritage in 2001, provide rich information about the history, society, economy and religious traditions of the Hittites and their neighbours.

Yearly archaeological campaigns led by current site director Professor Andreas Schachner of the Istanbul Department of the German Archaeological Institute continue to add to the cuneiform finds. Most of the texts are written in Hittite, the oldest attested Indo-European language and the dominant language at the site. Yet the excavations of this year yielded a surprise. Hidden in a cultic ritual text written in Hittite is a recitation in a hitherto unknown language.

Professor Daniel Schwemer, head of the Chair of Ancient Near Eastern Studies at Julius-Maximilians-Universität (JMU) Würzburg in Germany, is working on the cuneiform finds from the excavation. He reports that the Hittite ritual text refers to the new idiom as the language of the land of Kalašma. This is an area on the north-western edge of the Hittite heartland, probably in the area of present-day Bolu or Gerede.

The discovery of another language in the Boğazköy-Hattusha archives is not entirely unexpected, as Daniel Schwemer explains: "The Hittites were uniquely interested in recording rituals in foreign languages."

Such ritual texts, written by scribes of the Hittite king reflect various Anatolian, Syrian, and Mesopotamian traditions and linguistic milieus. The rituals provide valuable glimpses into the little known linguistic landscapes of Late Bronze Age Anatolia, where not just Hittite was spoken. Thus cuneiform texts from Boğazköy-Hattusha include passages in Luwian and Palaic, two other Anatolian-Indo-European languages closely related to Hittite, as well as Hattic, a non-Indo-European language. Now the language of Kalasma can be added to these.

Being written in a newly discovered language the Kalasmaic text is as yet largely incomprehensible. Daniel Schwemer’s colleague, Professor Elisabeth Rieken (Philipps-Universität Marburg), a specialist in ancient Anatolian languages, has confirmed that the idiom belongs to the family of Anatolian-Indo-European languages.

According to Rieken, despite its geographic proximity to the area where Palaic was spoken, the text seems to share more features with Luwian. How closely the language of Kalasma is related to the other Luwian dialects of Late Bronze Age Anatolia will be the subject of further investigation.

The Anatolian languages in the Indo-European language family are the least similar to other Indo-European language, which many linguists have interpreted as evidence of their deep time depth in the Indo-European language family. Some linguists have even suggested that the Indo-European languages have their origins in Anatolia and that their expansion from the Pontic Caspian steppe was a secondary migration. 

The linguists who take these positions are wrong. None of the other evidence is consistent with an old Indo-Anatolian languages hypothesis.

Instead, the Anatolian languages arrived in Anatolia from migrants ultimately derived from the Pontic Caspian steppe like Indo-European populations elsewhere. But they are relatively diverged from other Indo-European languages because the Copper Age Hattic society which the Hittites conquered and ultimately ruled, had far more staying power than the other societies were the Indo-European languages replaced Neolithic languages and Copper Age languages. The Hattic language survived as a liturgical language for many centuries after its speakers were conquered by the Hittites and it has far more substrate influence than other Neolithic substrate languages that Indo-European language experienced.

Also, the Hattic substrate language was itself greatly diverged from substrate languages descended from Western Anatolian Neolithic languages found in Europe (Basque is probably the sole living language descendant of this family of languages), whose more limited influence on the Indo-European languages of the people who conquered them was similar because the substrate languages had a common origin about two to three thousand years earlier. The early metal age Hattic people's language replaced the Neolithic languages of Anatolia when then migrated to this area from the highlands to its east.

Based on toponyms and personal names, however, it may have been related to the otherwise-unattested Kaskian language. Certain similarities between Hattic and both Abkhazo-Adyghean and Kartvelian languages have led to proposals by some scholars about the possibility of a linguistic bloc from central Anatolia to the Caucasus.

It seems likely that Minoan was also part of a linguistic macro-family that included Hattic, other Caucasian language families, and possibly other now extinct ergative languages of the region. 

Archaeological evidence, early historical written records from a Mesopotamian trading outpost at the south central fringe of Anatolia, and genetic evidence all support a late arrival of Anatolian languages to Anatolia (ca. 2000 BCE), followed by an adoption of the Anatolian languages there through language shift due to elite dominance of Hittite and other Anatolian language speakers, in part, due to their early superiority in metallurgy. They didn't leave much of a demic impact on the population of Anatolia, in stark contrast to the large scale male dominated demic near replacement seen in other areas where Indo-Europeans conquered territories whose Neolithic civilizations had collapsed due to serious climate events and soil exhaustion from their primitive agricultural methods.

The attested Indo-European language that was probably closest to proto-Indo-European (i.e.  the most basal attested Indo-European language) is Tocharian, which was spoken in the Tarim Basin for centuries by phenotypically and genetically West Eurasian peoples.

Proto-Indo-European languages probably originate in the Sredny Stog culture (ca. 4500 BCE to 3500 BCE), possibly fusing, on a more or less equal basis early herder languages of the Pontic Caspian steppe based upon Eastern hunter-gatherer languages of the region (possibly with some borrowing from Caucasian hunter-gather languages from whom they may have acquired some wives in a contact zone near the northern slope of the Caucasian mountains), with early Neolithic farmers on the frontier of farming at the time speaking a language derived from a Western Anatolian Neolithic language. The Khvalynsk culture of Western steppe herders (in the middle Volga region) and the Neolithic first farmers from the Cucuteni-Trypillia culture (centered in modern day Moldova and Western Ukraine) probably both contributed to the hybrid Sredny Stog culture that emerged in their contact zone. The nearby and roughly contemporaneous Cernavodă culture may have been another of the very earliest linguistically Indo-European societies. There are strong hints that the Sredny Stog culture was either the first to have domesticated the horse, or was one of the first cultures to have domesticated horses which were domesticated nearby.

More On Wide Binary Stars

This somewhat mixed result is the latest episode in the wide binary star dynamics debate. It shows strong signs of non-Newtonian behavior, although not necessarily MOND-like. This is important because dark matter particle models shouldn't produce non-Newtonian dynamics in wide binary stars.

It is found that Gaia DR3 binary stars selected with stringent requirements on astrometric measurements and radial velocities naturally satisfy Newtonian dynamics without hidden close companions when projected separation s>2 kau, showing that pure binaries can be selected. It is then found that pure binaries selected with the same criteria show a systematic deviation from the Newtonian expectation when s<2 kau. 

When both proper motions and parallaxes are required to have precision better than 0.003 and radial velocities better than 0.2, I obtain 1558 statistically pure binaries within a 'clean' G-band absolute magnitude range. From this sample, I obtain an observed to Newtonian predicted kinematic acceleration ratio of γ(g)=g(obs)/g(pred)=1.43+0.23−0.19 for acceleration <10^−10 m s^−2, in excellent agreement with a recent finding 1.43±0.06 for a much larger general sample with the amount of hidden close companions self-calibrated. I also investigate the radial profile of stacked sky-projected relative velocities without a deprojection to the 3D space. The observed profile matches the Newtonian predicted profile for s<2 kau without any free parameters but shows a clear deviation at a larger separation with a significance of 4.6σ. The projected velocity boost factor for s>8 kau is measured to be γ(v(p))=1.18±0.06 matching γ(g)‾‾√. 

Finally, for a small sample of 23 binaries with exceptionally precise radial velocities (precision <0.0043) the directly measured relative velocities in the 3D space also show a boost at larger separations. These results robustly confirm the recently reported gravitational anomaly at low acceleration for a general sample.

Kyu-Hyun Chae, "Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions" arXiv:2309.10404 (September 19, 2023) (submitted to ApJ (this new work complements the paper ApJ, 952, 128 (arXiv:2305.04613) in an important way).

CP Violation In The Standard Model Quantified And More

There are two components of the Standard Model of Particle Physics that violate charge parity (CP) conversation, which is to say that the laws of physics are asymmetric between interactions going forward in time and interactions going backward in time. One is the CP violation parameter of the four parameter CKM matrix, which is called beta (β), and applies to W boson mediated changes in quark flavor. The other is the CP violation parameter of the PMNS matrix which governs neutrino flavor oscillations, which has been measured only crudely but is very likely to be non-zero given current measurements to date.

A new measurement of the CKM matrix CP violation parameter using the decays of electromagnetically neutral B mesons has been made by the LHCb experiment  at the Large Hadron Collider (LHC). This is "the most precise single measurement of the CKM angle β to date and is more precise than the current world average." The status quo leading up to this new measurement was as follows:

Measurements of CP violation in neutral meson decays to charmonium final states have thus resulted in a high degree of precision for the angle β of the CKM matrix: sin(2β) = 0.699 ± 0.017. The first observation of CP violation in the B-meson system was reported in the B0→J/ψK0 S channel by the BaBar andBelle collaborations. The measurement of the CP-violation parameters in (2β) has been updated several times by these experiments, and more recently by the LHCb andBelleII collaborations.

The new paper, regrettably, doesn't actually report its measured value of β but does provide a formula to convert a parameter that it does measure to β. Assuming no beyond the Standard Model physics:

The parameter S can be related to the CKM angle β as S = sin(2β+∆ϕd+ . . . ). . . . Contributions from penguin topologies to the decay amplitude that cause an additional phase shift ∆ϕd are CKM suppressed, hence deviations of S from sin(2β) are expected to be small in the Standard Model.

The bottom line value, simultaneously fitting data from three different decay modes for S is S = 0.717 ± 0.013(stat) ± 0.008(syst).

Another new paper recaps the latest and greatest measurements of the masses of the five hadronizing Standard Model quarks and the strong force coupling constant:

When And Why Was The Sahara Green?

We've made lots of progress in understanding African Paleoclimates. 

The two images above are from the paper cited below. The image below is from Wikipedia (see also a list of notable climate events here and here).

There is widespread evidence that the Sahara was periodically vegetated in the past, with the proliferation of rivers, lakes and water-dependent animals such as hippos, before it became what is now desert. These North African Humid Periods may have been crucial in providing vegetated corridors out of Africa, allowing the dispersal of various species, including early humans, around the world.

The so-called ‘greenings’ are thought to have been driven by changes in Earth’s orbital conditions, specifically Earth’s orbital precession. Precession refers to how Earth wobbles on its axis, which influences seasonality (i.e. the seasonal contrast) over an approximate 21,000-year cycle. These changes in precession determine the amount of energy received by the Earth in different seasons, which in turn controls the strength of the African Monsoon and the spread of vegetation across this vast region.

A major barrier to understanding these events is that the majority of climate models have been unable to simulate the amplitude of these humid periods, so the specific mechanisms driving them have remained uncertain.

This study deployed a recently-developed climate model to simulate the North African Humid periods to greatly advance understanding of their driving mechanisms.

The results confirm the North African Humid Periods occurred every 21,000 years and were determined by changes in Earth’s orbital precession. This caused warmer summers in the Northern Hemisphere, which intensified the strength of the West African Monsoon system and increased Saharan precipitation, resulting in the spread of savannah-type vegetation across the desert.

The findings also show the humid periods did not occur during the ice ages, when there were large glacial ice sheets covering much of the high latitudes. This is because these vast ice sheets cooled the atmosphere and suppressed the tendency for the African monsoon system to expand. This highlights a major teleconnection between these distant regions, which may have restricted the dispersal of species, including humans, out of Africa during the glacial periods of the last 800,000 years.

From a Science Daily press release. 

The paper and its abstract are as follows:

The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most climate models cannot reconcile the magnitude of these events and so the driving mechanisms remain poorly constrained. Here, we utilise a recently developed version of the HadCM3B coupled climate model that simulates 20 NAHPs over the past 800 kyr which have good agreement with NAHPs identified in proxy data. 

Our results show that precession determines NAHP pacing, but we identify that their amplitude is strongly linked to eccentricity via its control over ice sheet extent. During glacial periods, enhanced ice-albedo driven cooling suppresses NAHP amplitude at precession minima, when humid conditions would otherwise be expected. 

This highlights the importance of both precession and eccentricity, and the role of high latitude processes in determining the timing and amplitude of the NAHPs. This may have implications for the out of Africa dispersal of plants and animals throughout the Quaternary.

Edward Armstrong, Miikka Tallavaara, Peter O. Hopcroft, Paul J. Valdes, "North African humid periods over the past 800,000 years." 14(1) Nature Communications (2023) (open access) DOI: 10.1038/s41467-023-41219-4

The Evolutionary Biology Of The Uncanny Valley

The obvious candidates giving rise to an evolutionary biology source for the uncanny valley effect in reality would be other archaic hominin species like Neanderthals, Denisovans, Homo erectus, and Homo floresiensis (a.k.a. "Hobbits"). And, this reaction may have evolved at the time of our pre-modern human ancestors because there were many species of the genus Homo in existence at that time, some of whom would have interacted with each other in Africa.

Less obviously, it could be something the developed to recognize when other people were suffering from diseases, physical and/or mental, or to trigger you not to trust what you see when you are under the influence of a hallucinogen.

It could also be a side effect our cognitive abilities developed for recognizing and evaluating other people, e.g., distinguishing people from another race or region, whose mechanism produces weird results when you are at the fringe of its domain of applicability.

Wikipedia notes at least nine theories to explain the psychological quirk, none of which is really dominant explanations in the academic community. They are:

Mate selection: Automatic, stimulus-driven appraisals of uncanny stimuli elicit aversion by activating an evolved cognitive mechanism for the avoidance of selecting mates with low fertility, poor hormonal health, or ineffective immune systems based on visible features of the face and body that are predictive of those traits.

Mortality salience: Viewing an "uncanny" robot elicits an innate fear of death and culturally supported defenses for coping with death's inevitability.... [P]artially disassembled androids...play on subconscious fears of reduction, replacement, and annihilation: (1) A mechanism with a human façade and a mechanical interior plays on our subconscious fear that we are all just soulless machines. (2) Androids in various states of mutilation, decapitation, or disassembly are reminiscent of a battlefield after a conflict and, as such, serve as a reminder of our mortality. (3) Since most androids are copies of actual people, they are doppelgängers and may elicit a fear of being replaced, on the job, in a relationship, and so on. (4) The jerkiness of an android's movements could be unsettling because it elicits a fear of losing bodily control.

Pathogen avoidance: Uncanny stimuli may activate a cognitive mechanism that originally evolved to motivate the avoidance of potential sources of pathogens by eliciting a disgust response. "The more human an organism looks, the stronger the aversion to its defects, because (1) defects indicate disease, (2) more human-looking organisms are more closely related to human beings genetically, and (3) the probability of contracting disease-causing bacteria, viruses, and other parasites increases with genetic similarity." The visual anomalies of androids, robots, and other animated human characters cause reactions of alarm and revulsion, similar to corpses and visibly diseased individuals.

Sorites paradoxes: Stimuli with human and nonhuman traits undermine our sense of human identity by linking qualitatively different categories, human and nonhuman, by a quantitative metric: degree of human likeness.

Violation of human norms: If an entity looks sufficiently nonhuman, its human characteristics are noticeable, generating empathy. However, if the entity looks almost human, it elicits our model of a human other and its detailed normative expectations. The nonhuman characteristics are noticeable, giving the human viewer a sense of strangeness. In other words, a robot stuck inside the uncanny valley is no longer judged by the standards of a robot doing a passable job at pretending to be human, but is instead judged by the standards of a human doing a terrible job at acting like a normal person. This has been linked to perceptual uncertainty and the theory of predictive coding.

Conflicting perceptual cues: The negative effect associated with uncanny stimuli is produced by the activation of conflicting cognitive representations. Perceptual tension occurs when an individual perceives conflicting cues to category membership, such as when a humanoid figure moves like a robot, or has other visible robot features. This cognitive conflict is experienced as psychological discomfort (i.e., "eeriness"), much like the discomfort that is experienced with cognitive dissonance. Several studies support this possibility. Mathur and Reichling found that the time subjects took to gauge a robot face's human- or mechanical-resemblance peaked for faces deepest in the uncanny valley, suggesting that perceptually classifying these faces as "human" or "robot" posed a greater cognitive challenge. However, they found that while perceptual confusion coincided with the uncanny valley, it did not mediate the effect of the uncanny valley on subjects' social and emotional reactions—suggesting that perceptual confusion may not be the mechanism behind the uncanny valley effect. Burleigh and colleagues demonstrated that faces at the midpoint between human and non-human stimuli produced a level of reported eeriness that diverged from an otherwise linear model relating human-likeness to affect. Yamada et al. found that cognitive difficulty was associated with negative affect at the midpoint of a morphed continuum (e.g., a series of stimuli morphing between a cartoon dog and a real dog). Ferrey et al. demonstrated that the midpoint between images on a continuum anchored by two stimulus categories produced a maximum of negative affect, and found this with both human and non-human entities. Schoenherr and Burleigh provide examples from history and culture that evidence an aversion to hybrid entities, such as the aversion to genetically modified organisms ("Frankenfoods"). Finally, Moore developed a Bayesian mathematical model that provides a quantitative account of perceptual conflict. There has been some debate as to the precise mechanisms that are responsible. It has been argued that the effect is driven by categorization difficulty, configural processing, perceptual mismatch, frequency-based sensitization, and inhibitory devaluation. 

Threat to humans' distinctiveness and identity: Negative reactions toward very humanlike robots can be related to the challenge that this kind of robot leads to the categorical human – non-human distinction. Kaplan stated that these new machines challenge human uniqueness, pushing for a redefinition of humanness. Ferrari, Paladino and Jetten found that the increase of anthropomorphic appearance of a robot leads to an enhancement of threat to the human distinctiveness and identity. The more a robot resembles a real person, the more it represents a challenge to our social identity as human beings.

Religious definition of human identity: The existence of artificial but humanlike entities is viewed by some as a threat to the concept of human identity. An example can be found in the theoretical framework of psychiatrist Irvin Yalom. Yalom explains that humans construct psychological defenses to avoid existential anxiety stemming from death. One of these defenses is 'specialness', the irrational belief that aging and death as central premises of life apply to all others but oneself. The experience of the very humanlike "living" robot can be so rich and compelling that it challenges humans' notions of "specialness" and existential defenses, eliciting existential anxiety. In folklore, the creation of human-like, but soulless, beings is often shown to be unwise, as with the golem in Judaism, whose absence of human empathy and spirit can lead to disaster, however good the intentions of its creator.

Uncanny valley of the mind or AI: Due to rapid advancements in the areas of artificial intelligence and affective computing, cognitive scientists have also suggested the possibility of an "uncanny valley of mind". Accordingly, people might experience strong feelings of aversion if they encounter highly advanced, emotion-sensitive technology. Among the possible explanations for this phenomenon, both a perceived loss of human uniqueness and expectations of immediate physical harm are discussed by contemporary research.

What Does A Theoretical Physicist's Office Look Like?

 

From 4gravitons.

The Imjin Wars In Korea

Incredibly destructive wars are nothing new.

[T]he most significant destruction on the Korean Peninsula was wrought by the Japanese invasions of the late sixteenth century. Nearly two million Koreans, a staggering 20 percent of the population, perished during the Imjin Wars, Toyotomi Hideyoshi’s campaigns of 1592-1598 to subjugate the Korean Peninsula. Hideyoshi’s object was the conquest of Ming China (1368-1644) but the result was to turn Korea into a ruined land.

From Sheila Miyoshi Jager, "The Other Great Game: The Opening of Korea and the Birth of Modern East Asia" (2023).

Strengthening Evidence Of Another Predicted Higgs Boson Decay Channel

This is now reasonably strong (3.4 sigma) evidence from the LHC of Higgs boson decays to a Z boson and a photon at a rate consistent with the Standard Model predicted branching fraction for decays of this kind.

This was first hinted at in April of 2022, and this report reiterates results announced in May of this year. 

The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision data sets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb−1 for each experiment, at a center-of-mass energy of 13 TeV. The measured signal yield is 2.2±0.7 times the Standard Model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.

ATLAS, CMS Collaborations, "Evidence for the Higgs boson decay to a Z boson and a photon at the LHC" arXiv:2309.03501 (September 7, 2023).

Evidence Of Warm Dark Matter Annihilation Undermined

A new study fails to replicate the findings of five out of six papers that claim to have seen a 3.5 keV radiation line which arguably is the footprint of dark matter annihilation, using the same underlying data. 

The new study, with multiple authors, argues that the backgrounds were not correctly modeled and also identifies other methodological flaws in those papers. This greatly weakens on line of evidence in support of particle dark matter that can annihilate into ordinary matter or photons through collisions with other dark matter particles, which if the data were more solid would support a popular version of a warm dark matter particle model.

At least at face value, this is a rather stunning refutation of the work of the authors of the previous papers.

The 3.5 keV line is a purported emission line observed in galaxies, galaxy clusters, and the Milky Way whose origin is inconsistent with known atomic transitions and has previously been suggested to arise from dark matter decay. We systematically re-examine the bulk of the evidence for the 3.5 keV line, attempting to reproduce six previous analyses that found evidence for the line. Surprisingly, we only reproduce one of the analyses; in the other five we find no significant evidence for a 3.5 keV line when following the described analysis procedures on the original data sets. For example, previous results claimed 4σ

evidence for a 3.5 keV line from the Perseus cluster; we dispute this claim, finding no evidence for a 3.5 keV line. We find evidence for background mismodeling in multiple analyses. We show that analyzing these data in narrower energy windows diminishes the effects of mismodeling but returns no evidence for a 3.5 keV line. We conclude that there is little robust evidence for the existence of the 3.5 keV line. Some of the discrepancy of our results from those of the original works may be due to the earlier reliance on local optimizers, which we demonstrate can lead to incorrect results. For ease of reproducibility, all code and data are publicly available.  

Christopher Dessert, Joshua W. Foster, Yujin Park, Benjamin R. Safdi, "Was There a 3.5 keV Line?" arXiv:2309.03254 (September 6, 2023).

Near Hominin Extinction About 870,000 Years Ago?

I have no doubt that there was a serious bottleneck in hominin populations at roughly the time claimed. But effective population size is a tricky statistic that is further from what people think it means than most people realize, so don't take the absolute magnitude of the bottleneck, or the naive assumptions about the census population of these archaic hominins at this time, too literally. As the New York Times explains:

[O]utside experts said they were skeptical of the novel statistical methods that the researchers used for the study. “It is a bit like inferring the size of a stone that falls into the middle of the large lake from only the ripples that arrive at the shore some minutes later,” said Stephan Schiffels, a population geneticist at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

The researchers also put too much faith in a model that assumes a single universal mutation rate for genetic evolution, when there is good research to suggest that some parts of the genome evolve at faster rates than other parts of the genome. On the scale of several tens of thousands of generations, those fine points could become important.

Modern humans evolved around 300,000 years ago, and the speciation event that the authors suggests might coincide with this population bottleneck would have given rise to the common ancestor of modern humans, Neanderthals, and Denisovans.

The circumstances driving this 117,000 year period in which hominins may have come close to extinction aren't entirely clear. The editor's summary states:

The model detected a reduction in the population size of our ancestors from about 100,000 to about 1000 individuals, which persisted for about 100,000 years. The decline appears to have coincided with both major climate change and subsequent speciation events.

The paper and its abstract are as follows:

Population size history is essential for studying human evolution. However, ancient population size history during the Pleistocene is notoriously difficult to unravel. 

In this study, we developed a fast infinitesimal time coalescent process (FitCoal) to circumvent this difficulty and calculated the composite likelihood for present-day human genomic sequences of 3154 individuals. 

Results showed that human ancestors went through a severe population bottleneck with about 1280 breeding individuals between around 930,000 and 813,000 years ago. The bottleneck lasted for about 117,000 years and brought human ancestors close to extinction. 

This bottleneck is congruent with a substantial chronological gap in the available African and Eurasian fossil record. Our results provide new insights into our ancestry and suggest a coincident speciation event.

Wangjie Hu et al., "Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition" Science 979-984 (September 1, 2023).

One very basic methodological issue with the speculation that hominins went nearly extinct around 870,000 years ago made by this study, for example, is that genetic information from currently living modern humans showing a population bottleneck only tells us about our direct ancestors. 

As of 870,000 years ago, there was at least one species of the genus Homo, Homo erectus which had already dispersed from Africa to Eurasia. There is good reason to believe that there may have actually been more than one at that point, because the most plausible characterization of Homo floresiensis on the island of Flores in Indonesia and similar archaic hominins in the Philippines, is that this is a more archaic hominin species than Homo erectus.

Therefore, it is possible that these archaic hominin species suffered less severe bottleneck effects somewhere in Eurasia or Oceania that was outside of Africa, which subsequent events, such as the expansion of modern humans, Neanderthals, and Denisovans into Eurasia or later climate catastrophes, or a combination of causes, led to the complete extinction of them at some later time, even though these archaic hominins had weathered the circumstances of 870,000 years ago better than our direct ancestors did.

One can imagine a narrative, for example, in which Homo erectus in Southeast Asia wasn't hit nearly so hard as African Homo erectus around 870,000 years ago, but then was driven to extinction there by the one two punch of the Toba eruption and modern human expansion into Southeast Asia in the wake of that eruption around 70,000 years ago. But, if hominins had gone extinct in Africa, the second prong of this one two punch would have never wiped out Southeast Asian Homo erectus and events might have played out differently. Southeast Asian Homo erectus might have back migrated to Africa 120,000 year or so after Africa experienced the conditions that drove hominins to near extinctions, when those conditions abated.

Further New York Times discussion of the new study (at the same link) notes that:

After decades of fossil hunting, the record of ancient human relatives remains relatively scarce in Africa in the period between 950,000 and 650,000 years ago. The new study offers a potential explanation: there just weren’t enough people to leave behind many remains, Dr. Hu said.

Brenna Henn, a geneticist at the University of California, Davis, who was not involved in the new study, said that a bottleneck was “one plausible interpretation.” But today’s genetic diversity might have been produced by a different evolutionary history, she added.

For example, humans might have diverged into separate populations then come together again. “It would be more powerful to test alternative models,” Dr. Henn said. 

Dr. Hu and his colleagues propose that a global climate shift produced the population crash 930,000 years ago. They point to geological evidence that the planet became colder and drier right around the time of their proposed bottleneck. Those conditions may have made it harder for our human ancestors to find food. 

But Nick Ashton, an archaeologist at the British Museum, noted that a number of remains of ancient human relatives dating to the time of the bottleneck have been found outside Africa. 

If a worldwide disaster caused the human population in Africa to collapse, he said, then it should have made human relatives rarer elsewhere in the world. 

“The number of sites in Africa and Eurasia that date to this period suggests that it only affected a limited population, who may have been ancestors of modern humans,” he said.