Grapes Were Domesticated In West Asia And The Caucasus 11,000 Years Ago

Contrary to previous understandings, grapes for food and wine were among the first domesticated crops in the Fertile Crescent Neolithic package of crops, and were independently domesticated in two places (the Near East and the Caucasus) with European grapes derived from the Near Eastern domestication. These grapes were then crossed with local wild grape varieties.

A new study reveals that Vitis vinifera was first domesticated around 11,000 years ago, according to a March 2 journal article in Science. The new research, based on genetics data of over 3,500 grape types, suggests that grapevines were first domesticated around 3,000 years prior than previously believed.

Previous archaeological research suggested that Vitis vinifera was first cultivated in the Transcaucasian region around 6,000— to 8,000 years ago, according to the National Library of Medicine.

The study conducted by an international group of researchers also reveals surprising information about the origins of grape domestication. The first cultivated grapevines were traced back to Western Asia and the Caucasus some 11,000 years ago.

Researchers analyzed genetic data from 3,525 domesticated and wild grape varieties to pinpoint the origin of table and wine grapes. It’s believed that the grapevines cultivated in Western Asia traveled to Europe, sparking agricultural pursuits in the area. The data indicates that humans dispersed grapevines along migratory routes into Europe and subsequently created unique grapevines growing both domestically and in the wild.

From here. The journal article and its summary and abstract as well as some key figures from the Supplemental Materials are as follows:

Origins and domestication of grapevines

Humans have extensively shaped the organisms around us through domestication. Although wine and table grapes have been important culturally for thousands of years, their origin has been difficult to pinpoint because of uneven sampling of modern cultivars. Dong et al. analyzed genetic data from about 3500 cultivated and wild grape varieties from around the world. The results of their analysis reveal the effects of climate on historic population sizes, suggest concurrent domestications of wine and table grapes, and identify variants associated with domestication traits such as berry color and palatability. These results increase our understanding of how humans and the environment shaped this domesticated crop. —CNS

Abstract

We elucidate grapevine evolution and domestication histories with 3525 cultivated and wild accessions worldwide. 

In the Pleistocene, harsh climate drove the separation of wild grape ecotypes caused by continuous habitat fragmentation. Then, domestication occurred concurrently about 11,000 years ago in Western Asia and the Caucasus to yield table and wine grapevines. The Western Asia domesticates dispersed into Europe with early farmers, introgressed with ancient wild western ecotypes, and subsequently diversified along human migration trails into muscat and unique western wine grape ancestries by the late Neolithic. 

Analyses of domestication traits also reveal new insights into selection for berry palatability, hermaphroditism, muscat flavor, and berry skin color. These data demonstrate the role of the grapevines in the early inception of agriculture across Eurasia.

Yang Dong, et al., "Dual domestications and origin of traits in grapevine evolution" 379 (6635) Science 892-901 (MARCH 2, 2023). DOI: 10.1126/science.add8655. First Supplemental Materials file here.

The abstract of a related commentary article is as follows:

The domestication of plants that underpin the rise of human civilization is increasingly recognized as a complex interplay of processes across a culturally connected landscape. On page 892 of this issue, Dong et al. reveal more of this complexity by reporting the unraveling of the evolutionary events that led to grape (Vitis vinifera ssp. vinifera) domestication. 

By incorporating the effects of glacial oscillations on biogeographical distributions of the wild progenitor (Vitis vinifera ssp. sylvestris) across Eurasia, they resolved two separate domestication processes from two distinct populations of sylvestris in the Near East and South Caucasus that were separated during the last glacial advance. They found that although the South Caucasus domestication is associated with early winemaking, the origin of wine in Western Europe is associated with cross-fertilization (introgression) between Western Europe’s wild populations and domesticated grapes originating from the Near East that were initially used as food sources.

Surprising Genetic Diversity Among European Hunter-Gatherers

Given the relative homogeneity of Y-DNA haplogroups (predominantly one clade of Y-DNA I) and mtDNA haplogroups (predominantly a few kinds of mtDNA U) among European hunter-gatherers before the Neolithic Revolution arrived there, you might expect a similar lack of diversity in their autosomal DNA. This turns out not to be the reality.

The role of the Italian refuge in during the Upper Paleolithic Ice Age and the repopulation of Europe that followed when it retreated has also been more or less completely upended. It was a dead end and completely replaced in the Mesolithic era.

New ancient DNA reported in an article in Nature reveals that there were great regional variation in the DNA and even phenotypes of European hunter-gatherers, despite the loss of diversity that it suffered during the Upper Paleolithic ice age there from which it was repopulated in the Mesolithic era from relict populations in what turn out to be basically two of three small communities in addition to migration from more distant parts of Southeast Europe and West Asia. 

According to the magazine Science at the link above:

[T]he Gravettians were not a single people. New DNA evidence, published today in Nature, shows Gravettians in France and Spain were genetically distinct from groups living in what is now the Czech Republic and Italy. “What we thought was one homogenous thing in Europe 30,000 years ago is actually two distinct groups,” says Mateja Hajdinjak, a molecular biologist at the Max Planck Institute for Evolutionary Anthropology who was not part of the new study.

The Gravettian data are part of a larger trove of ancient European DNA that reveals striking genetic diversity within apparently unified prehistoric cultures. The sweeping study analyzed 116 newly sequenced genomes and hundreds of previously published ones, ranging from about 45,000 years ago, when the first modern humans reached the continent, to about 6000 B.C.E., and from the Iberian Peninsula to the western steppes of modern-day Russia. . . .

Many of the samples were in poor condition and some came from unusual contexts, like the now-submerged landscape between the British Isles and the Netherlands known as Doggerland. New analytical methods and increasingly powerful DNA sequencing tools enabled researchers to squeeze information from extremely degraded bones and teeth, including some that contained just 1% of their original genetic material. . . .

The DNA also sheds light on what happened to these ancient Europeans when the climate worsened between 25,000 and 19,000 years ago, a time known as the last glacial maximum when much of Northern and central Europe was blanketed in ice more than 1 kilometer thick. Archaeologists had assumed people including the Gravettians retreated into ice-free areas in southern Europe beginning about 26,000 years ago, then filtered back north several thousand years later as the glaciers melted. That scenario appears to hold true in the Iberian Peninsula and the south of France: People living there before the ice reached its peak persist through the worst of the cold spell, then surge back north and east as the continent warms.

But the Italian Peninsula, long thought to have been a relatively secure refuge, showed something different. Despite what looked to archaeologists like evidence of continuous occupation during and after the glacial maximum, DNA reveals the refuge was actually a dead end. “We expected Italy to be a climate refugium, but there’s a sharp and complete turnover—it’s a big surprise,” Posth says. “The Gravettian population completely disappears.” Instead, after the glacial maximum, people in Italy show genetic links to the Near East, suggesting a new population arrived from the Balkans. . . .

About 14,000 years ago, when temperatures across the continent rose sharply in the space of a few centuries, archaeologists recognized cultural changes. But they thought the changes reflected an existing population adapting to hunt in warmer, more heavily forested landscapes. Instead, DNA shows an almost complete population replacement: The people who survived the glacial maximum, known as the Magdalenians, all but vanish and are replaced by populations moving north from postglacial Italy.

The study also looked at the final era of hunter-gatherers in Europe, beginning 10,000 years ago as warming continued to transform the open steppe to dense forests and rich wetlands. Here, again, the genes revealed a surprising wrinkle: Despite broadly similar hunting and gathering lifestyles, people in Western Europe remain genetically distinct from those east of the Baltic Sea.

They even looked different: Genetic data suggest that before the arrival of farmers in northern Europe around 6000 B.C.E., hunter-gatherers in Western Europe had dark skin and light eyes. People in Eastern Europe and Russia, meanwhile, had light skin and dark eyes. Most surprising, despite the lack of geographic barriers between modern-day Germany and Russia, the two groups spent millennia not mingling. “From 14,000 years ago to 8000 years ago, they do not mix at all,” Posth says. But he acknowledges that the team’s samples don’t cover the continent completely, and the likely contact zones—in Poland and Belarus, for example—lack samples. More genetic data from those areas might show the two populations mixing locally.

The source article and its abstract are as follows:

Modern humans have populated Europe for more than 45,000 years. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. 

We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe, but resembles that of preceding individuals associated with the Aurignacian culture. 

This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. 

Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. 

After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants. 

Posth, C., Yu, H., Ghalichi, A. et al. Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers. 615 Nature 117–126 (March 1, 2023) (open access). https://doi.org/10.1038/s41586-023-05726-0

The paper also notes that:

A companion paper describes genome-wide data of a 23,000-year-old Solutrean-associated individual from southern Iberia that extend the evidence of genetic continuity across the LGM in southwestern Europe.

The reference to this paper is as follows:

Villalba-Mouco, V. et al. A 23,000-year-old southern-Iberian individual links human groups that lived in Western Europe before and after the Last Glacial Maximum. Nat. Ecol. Evol., https://doi.org/10.1038/s41559-023-01987-0 (2023).

The abstract to that open access paper states:

Human populations underwent range contractions during the Last Glacial Maximum (LGM) which had lasting and dramatic effects on their genetic variation. The genetic ancestry of individuals associated with the post-LGM Magdalenian technocomplex has been interpreted as being derived from groups associated with the pre-LGM Aurignacian. However, both these ancestries differ from that of central European individuals associated with the chronologically intermediate Gravettian. Thus, the genomic transition from pre- to post-LGM remains unclear also in western Europe, where we lack genomic data associated with the intermediate Solutrean, which spans the height of the LGM. Here we present genome-wide data from sites in Andalusia in southern Spain, including from a Solutrean-associated individual from Cueva del Malalmuerzo, directly dated to ~23,000 cal yr BP. The Malalmuerzo individual carried genetic ancestry that directly connects earlier Aurignacian-associated individuals with post-LGM Magdalenian-associated ancestry in western Europe. This scenario differs from Italy, where individuals associated with the transition from pre- and post-LGM carry different genetic ancestries. This suggests different dynamics in the proposed southern refugia of Ice Age Europe and posits Iberia as a potential refugium for western European pre-LGM ancestry. More, individuals from Cueva Ardales, which were thought to be of Palaeolithic origin, date younger than expected and, together with individuals from the Andalusian sites Caserones and Aguilillas, fall within the genetic variation of the Neolithic, Chalcolithic and Bronze Age individuals from southern Iberia.

Impossible Early Galaxies Firmly Established

The New Paper In Nature

A new paper in Nature (and its abstract) are as follows (footnotes in the abstract omitted):

Galaxies with stellar masses as high as ~ 10^11 solar masses have been identified out to redshifts z ~ 6, approximately one billion years after the Big Bang. It has been difficult to find massive galaxies at even earlier times, as the Balmer break region, which is needed for accurate mass estimates, is redshifted to wavelengths beyond 2.5 μm. Here we make use of the 1-5 μm coverage of the JWST early release observations to search for intrinsically red galaxies in the first ≈ 750 million years of cosmic history. In the survey area, we find six candidate massive galaxies (stellar mass > 10^10 solar masses) at 7.4 ≤ z ≤ 9.1, 500–700 Myr after the Big Bang, including one galaxy with a possible stellar mass of ~10^11 solar masses. If verified with spectroscopy, the stellar mass density in massive galaxies would be much higher than anticipated from previous studies based on rest-frame ultraviolet-selected samples.

Labbé, I., van Dokkum, P., Nelson, E. et al. "A population of red candidate massive galaxies ~600 Myr after the Big Bang." Nature (February 22, 2023). https://doi.org/10.1038/s41586-023-05786-2 (Open access version available at https://arxiv.org/abs/2207.12446).

Why Is This Paper Important?

The Bottom Line

The paper is notable because it is the most extreme and definitive example of astronomy observations that give rise to the "impossible early galaxy problem" of the LamdaCDM model which is often described as the "Standard Model of Cosmology."

Simply put, the LambdaCDM model predicts that the formation of galaxies of this size should take place far later after the Big Bang than the time frames in which they have been observed by astronomers to exist.

Previous LambdaCDM Galaxy Formation Predictions Compared

One widely accepted prediction was made by astrophysicist Carlos Frenk at a scientific conference in October of 1998 based upon LambdaCDM simulations had been that there would be no galaxies before redshift z=7. This corresponds to a look back time of 13.01 billion years, which is about 770 million years after the Big Bang, which implies that galaxies start forming about 55% to 10% more slowly in the LambdaCDM model than the earliest galaxies must start to form given what has been observed to form so far by the JWST. And, new observations of earlier galaxies over the lifetime of the JWST's mission can only make that gap worse, not weaker, if even earlier galaxies are located.

Like most things in astronomy and cosmology, this LambdaCDM prediction for the time period in which galaxies start to form had a margin of error, but it wasn't a big one and had largely been confirmed by later calculations and simulations made in using the bare LambdaCDM model over the next quarter of a century. And, the LambdaCDM model was so admirable, in part, because it had so few complications and parameters to leave wiggle room in its predictions, and yet was still a good fit to the data for decades.

But now, the new paper in Nature is reporting six reasonably large galaxies at redshifts of z=7.4 ≤ z ≤ 9.1, which at the high end, is much earlier in time than Frenk's LambdaCDM model prediction of z=7. Frenck's 1998 prediction has been only slightly tweaked over the next quarter century and is a precise enough prediction to be significantly different, statistically, from the results announce in the new paper in Nature.

The Impossible Early Galaxies Problem

A published paper from 2016 articulated the "impossible early galaxies" problem as follows:

The current hierarchical merging paradigm and ΛCDM predict that the z∼ 4-8 universe should be a time in which the most massive galaxies are transitioning from their initial halo assembly to the later baryonic evolution seen in star-forming galaxies and quasars. However, no evidence of this transition has been found in many high-redshift galaxy surveys including CFHTLS, Cosmic Assembly Near-infrared Deep Extragalactic Survey (CANDELS), and Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH), which were the first studies to probe the high-mass end at these redshifts. Indeed, if halo mass to stellar mass ratios estimated at lower-redshift continue to z∼ 6-8, CANDELS and SPLASH report several orders of magnitude more M∼ 10^12-13M⊙ halos than is possible to have been formed by those redshifts, implying that these massive galaxies formed impossibly early.

We consider various systematics in the stellar synthesis models used to estimate physical parameters and possible galaxy formation scenarios in an effort to reconcile observation with theory. Although known uncertainties can greatly reduce the disparity between recent observations and cold dark matter merger simulations, there remains considerable tension with current theory even if taking the most conservative view of the observations.

Steinhardt, Charles. L. ; Capak, Peter; Masters, Dan; Speagle, Josh S., "The Impossible Early Galaxies Problem" 824(1) The Astrophysical Journal, article id. 21, 9 pp. (June 2016). DOI: 10.3847/0004-637X/824/1/21 (open access copy available at arXiv:1506.01377).

Thus, there were strong observational hints that there might be an "impossible early galaxy problem", for example, from the Hubble space telescope's observations and other "telescopes" (using the term loosely to describe a variety of astronomy instruments) that can probe highly redshifted objects long before the paper above published yesterday in Nature based upon JWST observations was released.

But, since the James Webb Space Telescope is so much more powerful than any earlier telescope when it comes to probing high redshift objects, what were previously strong hints that there might be big galaxies very soon after the Big Bang turned almost immediately after the JWST came online into multiple clear and unequivocal examples of galaxies of given sizes long before LambdaCDM said that they should exist. The JWST has also seen more galaxies at higher redshifts (i.e. more recently after the Big Bang) than any other "telescopes" before it has (even though it has been on line only briefly). This paper discusses the oldest galaxies seen to date, just 500-700 million years after the Big Bang, that look far more like modern galaxies than the LambdaCDM model should have made possible at this early time period in the universe.

To oversimplify the narrative somewhat, LambdaCDM assumes that in the early universe clumps of dark matter start to accumulate from random differences in matter density, which make it possible for ordinary matter to become concentrated enough to form stars, which in turn end up in clumps of proto-galaxies. These clumps undergoing a "hierarchal" process of repeated mergers and the collide into each other, until they eventually form modern sized galaxies.

The LambdaCDM model, once its six parameters are fitted to astronomy observations, provides data that makes it possible to make reasonable estimates of the rate at which dark matter becomes clumpy, the rate at which stars form, and the rate at which mergers occur, from which it is possible to make reasonable estimates of when galaxies of a certain size ought to appear.

But evidence provided by the JWST, exemplified by this paper with the earliest examples of early galaxies, makes clear that either something about the calculations used to make those predictions, or the LambdaCDM model itself, are wrong in this respect.

The jury is out regarding why galaxies formed much earlier than expected in the LambdaCDM model, even though something is clearly amiss.

What About The LambdaCDM Model Does This Paper Show Is Broken?

One of the main pieces of experimental evidence that previously inspired confidence in the accuracy of the LambdaCDM model was its ability to describe essentially all cosmological scale observations at a large scale structure level with just six astronomy observation fixed parameters, each of which has been measured with some precision.

The LambdaCDM model, once its six parameters are fitted, is, for example, an extraordinarily good match to the observed pattern of the cosmic background radiation (CMB) which came into being during the "recombination era" about 0.38 million years after the Big Bang. (See generally here for the conventional chronology of the universe after the Big Bang in cosmology.) Star and galaxy formation can't happen in any appreciable amount until after the recombination era when ordinary matter and photons (i.e. "radiation") decouple from each other because protons and electrons have been bound together into neutral atoms and the temperature of the universe has cooled sufficiently to allow for greater clumping of matter. So, we think that LambdaCDM gets the "starting line" of the star and galaxy formation process right even after this new paper.

But, the new paper's observations imply that the universe went from giving birth to its first stars after recombination ended, to producing galaxies similar in scale to many galaxies we see today at very low redshifts (about 13,780 million years after recombination), in just 500 to 700 million years. This strongly suggests that some other part of the LambdaCDM model, that crops up later in the history of galaxy formation in the universe and the larger span of the chronology of cosmology, is broken.

Are The Observations In This Paper Credible And Likely To Hold Up?

This result is highly credible because it confirms pre-JWST strong hints that these early galaxies existed. As noted above "high-redshift galaxy surveys including CFHTLS, Cosmic Assembly Near-infrared Deep Extragalactic Survey (CANDELS), and Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH)" were already pointing to this result seven years ago, although much more equivocally than the new data from the JWST does.

The new paper's results are also credible observations because many other JWST observations also identify early galaxies, even though they have not yet been published, have been released to the public, and in some cases have been disclosed in preprints of articles that have been accepted for publication in leading astronomy journals (e.g. here and here and here). So, independent confirmations of the existence of early galaxies established in the Nature article using JWST observation of other candidate galaxies at very high redshifts over the course of the next year or so, are a near certainty.

Another reason that this result is credible is that the impossible early galaxy problem with the LambdaCDM model isn't the only recent crack in that model's predictions.

A full review of discrepancies between astronomy observations and the LambdaCDM model is beyond the scope of this thread. But it suffices to say that there are half a dozen or a dozen or so distinct and independent discrepancies between LambdaCDM model predictions and astronomy observations that are currently being actively investigated in areas that range from galaxy and galaxy cluster observations to different kinds of cosmology scale observations.

Some of those discrepancies may turn out to be experimental methodology issues or require slight tweaks to how the LambdaCDM predictions are calculated that are no big deal in the greater scheme of things. Others discrepancies, however, may turn out to be as serious a challenge to the LambdaCDM model as the impossible early galaxy problem that the new paper in Nature has highlighted.

This is a very different situation than the one that exists for the Standard Model of Particle Physics, where every time a discrepancy or tension between the Standard Model's predictions and experiment has cropped up over the last half century (except with respect to neutrino mass), it has subsequently promptly been ruled out with more experiments and better analysis, and there are only a few weak discrepancies between the Standard Model and experiment currently in play.

So, the scientific community is already primed right now to be more receptive to challenges to the "Standard Model of Cosmology" than it is to tensions between experimental results and the Standard Model of Particle Physics.

Alternatives To The LambdaCDM Model

If the LambdaCDM model is "broken" what alternatives exist to it?

There are multiple possible ways that the LambdaCDM model could be tweaked. One of those many possible alternatives is to look at a gravity based explanation of dark matter phenomena.

Models that attempt to explain dark matter phenomena with a modification to the laws of gravity or how they operate, rather than with dark matter particles, generically predict earlier galaxy formation than the LambdaCDM model does, consistent with the new JWST observations.

For example, galaxies were predicted to form in the time frame now observed by Bob Sanders in October of 1997 in the MOND (modified Newtonian dynamics) paradigm which is the most widely discussed gravitation based approach to explaining dark matter phenomena, even though it is itself a mere phenomenological toy model theory. Sanders predicted that: “Objects of galaxy mass are the first virialized objects to form (by z=10) and larger structure develops rapidly.” This is a little less than 500 million years after the Big Bang.

A JWST observation of a galaxy that may be as earlier as z=9.1 after only an initial quick search shortly after it has become operational, is consistent with that prediction and is at odds with the LambdaCDM prediction.

(This post substantially recaps a Physics Forum post here).

Early Bows and Arrows In Context

Researchers found the telltale stone points in a rock shelter that was inhabited by early modern humans about 54,000 years ago in what is now southern France. Until now, 12,000-year-old wooden artifacts in Northern Europe were the earliest concrete evidence of bow-and-arrow technology on the continent.

The stone points are the earliest evidence in Europe for the use of bows and arrows by early modern humans and suggests that the technology may have given this human lineage an edge over the Neanderthals for hunting prey, the researchers propose in a paper published Feb. 22 in the journal Science Advances. 

. . .

In a study published in the journal Science Advances last year, many of the same researchers reported finding teeth and stone artifacts that showed early modern humans occupied the site between 56,700 and 51,700 years ago — pushing back the earliest known date of the arrival of early modern humans in Europe by about 10,000 years. . . .

The stone and bone points found in the rock shelter at Grotte Mandrin in the Rhône River valley aren't the oldest evidence for bows and arrows anywhere, however; supposed arrowheads, also associated with early modern humans, found in South Africa are more than 70,000 years old.

From Live Science.

The Upper Paleolithic era which corresponds roughly to the period when behaviorally modern human hunter-gatherers appear, long after anatomically modern humans appear ca. 200,000-300,000 years ago. It has conventionally been dated to about 50,000 years ago (reinforced by estimates from contemporary genetics to find a common ancestor for non-African humans). 

But, really start to sea behavioral modernity that distinguished modern humans from other archaic hominins, including fishing implements, bone tools, and artistic work, as well as bows and arrows, at about 70,000 years ago in Africa, which is also around the time that modern humans start to enter Southeast Asia and Australia. 

This was probably a time of expansions of a culture of modern humans that made these behavioral leaps, not just leaving Africa, but also within Africa, that would more or less put in place the demographic make up of Africa until the Holocene era (ca. 10,000 years ago). One major development between the start of behavioral modernity ca. 70,000 years ago, and the Holocene, ca. 10,000 years ago, however, was the domestication of the dog, perhaps 30,000 years ago.

We can say with increasing confidence that some modern humans did leave Africa earlier than 70,000 years ago, reaching the Levant, Arabia, and India. But, the earliest evidence of modern humans in Europe dates only to about 54,000 years ago, modern humans reached the Americas much later, and they reached much of Oceania (beyond the Philippines and Papua New Guinea) only in the Holocene era.

Also, humans were completed banished from most of Europe and Northern and Central Asia in the Ice Age that brought the Last Glacial Maximum ca. 20,000 years ago, except for a handful of refuges in Beringia, Iberia, Italy, the Caucasus Mountains, and perhaps the Altai and even Tibet, only to repopulate these regions afterwards. 

There may have been a tiny and marginally viable population of modern humans in the Americas prior to the Last Glacial Maximum, but they didn't thrive and may even have gone extinct before being replenished the glaciers that encased much of northern North America finally started to subside.

Black Holes Are Not A Source Of Dark Energy

This recent claim picked up in the mass media struck me as dubious. A new preprint explains why.

The hypothesis that the mass of BHs increases with time according to the same law as the volume of the part of the Universe containing it and therefore the population of BHs is similar to dark energy in its action was recently proposed. We demonstrate the reasons why it cannot be accepted, even if all the assumptions on which this hypothesis is based are considered true.

S L Parnovsky, "Can black holes be a source of dark energy?" arXiv:2302.13333 (February 26, 2023).

Homo Erectus Held On Until 100,000 Years Ago In Indonesia

The three year old article quoted below speculates that some Southeast Asians may have a small amount of Homo Erectus ancestry. But I think that this is unlikely to have happened directly, due to the lack of overlap in human and Homo Erectus occupation and genetic differences too great to permit the birth of a hybrid individual (although it could be that modern humans dealt the death blow to relict Homo Erectus when they first encountered them en route to Australia and Papua New Guinea, which contrary to the Science article, happened closer to 70,000 years ago, perhaps shortly after the volcanic Toba eruption in Indonesia ca. 74,000 years ago).

But, it isn't inconceivable that an archaic Denisovan individual, a sister species to the Neanderthals and one source of archaic hominin admixture in modern humans, might have admixed with Homo Erectus, with whom they probably co-habited in Indonesia for thousands of years, leading to a small proportion of a modern human with Denisovan ancestry's Denisovan sourced DNA including Homo Erectus ancestry (perhaps about a percent of a percent, i.e. a few parts per 10,000). Indeed, there are some hints in Denisovan DNA of small amounts of admixture with H. erectus, although this is too small to be definitively identified separately in modern humans with Denisovan ancestry (which can be as high as about 5% of some aboriginal Australians and Papuans and Negritos from the Philippines today).

The time coincidence with the genetically estimated most recent common ancestor of Neanderthals and Denisovans, however, is a pretty close match to the time that H. erectus disappears in the archaeological record outside Indonesia, which also isn't that remote from the first appearance of modern humans. Therefore, it wouldn't be unreasonable to guess that modern humans, Neanderthals, and Denisovans were the cause of the extinction of H. erectus in their respective regions. 

If so, Denisovans may have been a very late arrival to the island of Java (i.e. ca. 100,000 years ago or later) and cohabited with them only briefly, which could explain the ability to H. erectus to persist there while going extinct everywhere else. It could also be the case that Denisovan's brought about the extinction of H. erectus in Indonesia tens of thousands of years before modern humans arrived on a path cleared by the Toba eruption.

H. floresiensis a.k.a. "hobbits" also co-habited in Indonesia with H. erectus and Denisovans (and possibly even modern humans), although it is unclear when they first appeared on the island of Flores. But, they were probably an even more basal (i.e. archaic) species of hominin than H. erectus such as H. habilis. So, they probably didn't directly admix genetically with Denisovans or modern humans due to their large genetic distance from them.

When seafaring modern humans ventured onto the island of Java some 40,000 years ago, they found a rainforest-covered land teeming with life—but they weren’t the first humans to call the island home. Their distant ancestor, Homo erectus, had traveled to Java when it was connected to the mainland via land bridges and lived there for approximately 1.5 million years. These people made their last stand on the island about 100,000 years ago, long after they had gone extinct elsewhere in the world, according a new study assigning reliable dates to previously found H. erectus fossils. 

. . . 

The newly dated fossils also bookend the existence of a remarkably long-lived human species, says Patrick Roberts, an archaeologist at the Max Planck Institute for the Science of Human History in Jena, Germany, who wasn’t involved with the study. 

. . .

H. erectus arose in Africa about 1.9 million years ago. These toolmakers with relatively large brains migrated out of Africa and across Asia, crossing into Java by land bridges about 1.6 million years ago, when savanna-like open woodland covered much of the land. Later, sea levels rose, isolating these ancient Javans on an island. Meanwhile, in Africa and mainland Asia, H. erectus disappeared by about 500,000 years ago. 

. . . 

In 2008 and 2010, [the new study’s lead author, paleoanthropologist Russell] Ciochon’s team re-excavated the site, turning up 867 new fossils belonging to deer, wild cattle, and an extinct, elephantlike animal called a stegodon. Based on photographs and documents from the original excavation, they established that some of the newly found animal fossils came from the same rich bone bed as the H. erectus fossils. The researchers applied five types of radiometric dating, including a new method that provides both minimum and maximum dates, to those animal fossils and the sediments around them. The team concluded that the bones were buried between 117,000 and 108,000 years ago, the researchers report . . . in Nature.

From Science (reporting on a December 18, 2019 article in Nature).

Sabine Hossenfelder On "What's Going Wrong With Particle Physics?"

This video is a great, compact summary of the sociological problems with the particle physics field, essentially summing up the premises of her book Lost in Math, namely, that lots of the theories being pursued are either not really problems, or are solutions that are profoundly disfavored empirically but are still being doggedly pursued in ever more byzantine variations.

Married To A Model

This year's Valentine's Day poem from 4 gravitons:

Married to a Model

If you ever face a physics class distracted,
Rappers and footballers twinkling on their phones,
Then like an awkward youth pastor, interject,
“You know who else is married to a Model?”

Her name is Standard, you see,
Wife of fifty years to Old Man Physics,
Known for her beauty, charm, and strangeness too.
But Old Man Physics has a wandering eye,
and dreams of Models Beyond.

Let the old man bend your ear,
you’ll hear
a litany of Problems.

He’ll never understand her, so he starts.
Some matters she holds weighty, some feather-light
with nary rhyme or reason
(which he is owed, he’s sure).

She’s unnatural, he says,
(echoing Higgins et al.),
a set of rules he can’t predict.
(But with those rules, all else is possible.)

Some regularities she holds to fast, despite room for exception,
others breaks, like an ill-lucked bathroom mirror.

And then, he says, she’ll just blow up
(when taken to extremes),
while singing nonsense in the face of Gravity.

He’s been keeping a careful eye
and noticing anomalies
(and each time, confronting them,
finds an innocent explanation,
but no matter).

And he imagines others
with yet wilder curves
and more sensitive reactions
(and nonsense, of course,
that he’s lived fifty years without).

Old man physics talks,
that’s certain.
But beyond the talk,
beyond the phases and phrases,
(conscious uncoupling, non-empirical science),
he stays by her side.

He knows Truth, 
in this world,
is worth fighting for.

Genius In Action

I went to a conference which was totally about my specialization, and one Ph.D student gave his presentation, sounding very nervous. I could barely follow his talk, and thought I must have forgotten a lot of things, it seemed beyond my knowledge. 

At the any questions stage, someone stood up, and suggested one part was wrong, with an alternative explanation, which seemed convincing - lots of people nodding, as he said what would have happened if the student speaker had been right. 

Then instantly a second person stood up and said the first critic was right about the error, but his explanation was wrong, and explained why it was wrong and gave a second alternative explanation. Wow, criticizing an explanation and alternative explanation on a complex subject he had just heard 10 seconds ago. Lots of people nodding and ooing "oh yes." 

Then a third person stood up, gave his name and was immediately recognized as a Nobel prize winner, (who just happened to be in town visiting an friend), but not a specialist in the topics of the conference. He told the original presenter what their error was, then told the first critic what was really wrong with his alternative explanation, told the second critic that he was wrong in each alternative he had offered (including his wrong explanation of what was wrong) and then explained what was really really going on.

Silence. Every one sat going through what this not a specialist had said about everything, and slowly we all started nodding in agreement. We were all wiped out by how he could correct things outside of his own specialism and also how we all took so long to work out he was right. Genius is truly impressive when it swings into action.

From here (with minor spelling and punctuation edits and paragraph breaks added). 

The Únětice Culture

The biggest unsolved mystery related to the Únětice culture is its language and its possible role as the linguistic ancestor of later Western European linguistic developments. 

It might have spoken, for example, a language which is a common ancestor of Italic and Celtic languages (i.e. proto-Italo-Celtic).

It is hard to know definitively what language its people spoke, however, because the culture didn't have a written language. But, similarities and differences between artifacts at Únětice sites and in other archaeological cultures, and the genetics of people from the culture, could inform this debate. Genetically, according to Wikipedia at the link above:

Haak et al. 2015 examined the remains of 8 individuals of the Unetice culture buried in modern-day Germany c. 2200–1800 BC. The 3 samples of Y-DNA extracted belonged to Y-haplogroups I2a2, I2c2 and I2, while the 8 samples of mtDNA extracted were determined to belong to haplogroup I3a (2 samples), U5a1, W3a1, U5b2a1b, H4a1a1, H3 and V. The examined Unetice individuals were found to be very closely related to peoples of the earlier Yamnaya culture, Bell Beaker culture and Corded Ware culture. Their amount of steppe-related ancestry is comparable to that of some modern Europeans.

Allentoft et al. 2015 examined the remains of 7 individuals of the Unetice culture buried in modern-day Poland and Czech Republic from c. 2300–1800 BC. The 7 samples of mtDNA extracted were determined to belong to haplogroup U4, U2e1f1, H6a1b, U5a1b1, K1a4a1, T2b and K1b1a. An additional male from the late Corded Ware culture or early Unetice culture in Łęki Małe, Poland of c. 2300–2000 BC was found to be a carrier of the paternal haplogroup R1b1a and the maternal haplogroup T2e. It was found that the people of the Corded Ware culture, Bell Beaker culture, Unetice culture and Nordic Bronze Age were genetically very similar to one another, and displayed a significant amount of genetic affinity with the Yamnaya culture.

The latest find about the culture, reported below, is also a useful reminder of how small scale even Bronze Age civilizations frequently were. It involves a settlement with the geographic size and population of a few urban residential city blocks, yet archaeologists see it as "a metallurgical centre and a stronghold of power" in that archaeological culture.

The Únětice culture, named for a type-site cemetery in the village of Únětice, was a Bronze Age culture that first emerged around 2300–1600 BC. The culture is distinguished by its characteristic metal objects, including ingot torcs, flat axes, flat triangular daggers, bracelets with spiral ends, disk- and paddle-headed pins, and curl rings, which are distributed over a wide area of Central Europe and beyond. One of the most important discoveries attributed to the Únětice Culture is the Nebra sky disc, found buried on the Mittelberg hill near Nebra in Germany. The Nebra sky disc is made from bronze and has a blue-green patina inlaid with gold symbols, that archaeologists have interpreted to represent the Sun or full moon, a lunar crescent, and the stars.

Archaeologists from the Adam Mickiewicz University have discovered a fortified Únětice Culture settlement, located near the town of Śmigiel, in the Kościan County of Poland. The settlement was situated on an island promontory, where 4,000-years-ago there was a lake on the edge of the Samica Kościańska valley, which today is a flowering meadow. The promontory was cut off from the mainland by a deep moat or ditch, with at least two rows of wooden palisades creating a fortified enclosure. The settlement occupied an area of 3.7 acres and supported a population of up to 100 people, which the researchers suggest was a metallurgical centre and a stronghold of power in the northern reaches of the Únětice Culture.

The results of the study, published in the “Journal of Archaeological Science: Reports” reveals that the settlement was discovered after a geoarchaeological analysis of the former lake which was formed when a glacier retreated around 18,000-years-ago. Based on core samples obtained by drilling, the lake started to shrink around 800 BC, eventually turning into a large bog at the turn of the era.

From here.

What Drives The Hubble Tension?

Stacy McGaugh suggests in his latest blog post that the Hubble tension is probably due to the estimate of Hubble's constant from the cosmic microwave background (CMB) which has gotten lower as greater precision measurements of it have been made, rather than from errors in recent time Hubble constant measurements as it is more common to suppose. 

He argues that observed early galaxy formation, which is contrary to the LambdaCDM model and thus not accounted for by it when calculating the early time Hubble constant from the CMB, is likely to be a big part of the discrepancy.

Blogroll Purge

Many of the "notable links" in the sidebar are dead or go to defunct blogs. I am purging them from the sidebar, but saving the names of the linked sites and the links that aren't dead for dormant blogs here for future reference to access the existing posts at those links, and also, in case the links are restored or the blogs are revived. I've also resorted the sidebar links alphabetically. The links removed were:

• Arcadian Gravity (author deceased)
• Archaeobotany and Domestication (deactivated account)
• Dienekes' Anthropology Blog (last activity January 1, 2021)
• Ethio Helix (last activity July 31, 2015)
• For What They Were . . . We Are (last activity December 21, 2018, closure announced in last post)
• Gauge Connection (last activity August 13, 2019)
• Linear Population Model (open to invited readers only)
• NJ's arya blog (last activity May 26, 2018)
• A Replicated Typo (last activity May 26, 2021)

A New Top Quark Mass Measurement

The latest top quark mass measurement at the Large Hadron Collider (LHC) is on the low side relative to previous measurements and the global average (which is 172.69 ± 0.30 from direct measurements), and is fairly precise despite using a fairly complex set of decay products to measure it. 

The new measurement is 1.93 sigma from the global average, so the new measurement is just barely consistent with the global average. In contrast, many other recent LHC measurements of the top quark mass have been high (almost two sigma high in at least one case) relative to the global average.

The mass of the top quark is measured in 36.3 fb−1 of LHC proton-proton collision data collected with the CMS detector at s√ = 13 TeV. The measurement uses a sample of top quark pair candidate events containing one isolated electron or muon and at least four jets in the final state. For each event, the mass is reconstructed from a kinematic fit of the decay products to a top quark pair hypothesis. A profile likelihood method is applied using up to five observables to extract the top quark mass. The top quark mass is measured to be 171.77 ± 0.37 GeV. This approach significantly improves the precision over previous measurements.

CMS Collaboration, "Measurement of the top quark mass using a profile likelihood approach with the lepton+jets final states in proton-proton collisions at s√ = 13 TeV" arXiv:2302.01967 (February 3, 2023).

Dark Matter Still Has Nothing On MOND In The Milky Way

The more complex dark matter particle mass models of the Milky Way, perform not better in describing what we see with other telescopes than the far simply MOND model when it comes to the Milky Way's rotation curve.

We use data from the Gaia DR3 dataset to estimate the mass of the Milky Way (MW) by analyzing the rotation curve in the range of distances 5 kpc to 28 kpc. 

We consider three mass models: the first model adds a spherical dark matter (DM) halo, following the Navarro-Frenk-White (NFW) profile, to the known stellar components. The second model assumes that DM is confined to the Galactic disk, following the idea that the observed density of gas in the Galaxy is related to the presence of more massive DM disk (DMD), similar to the observed correlation between DM and gas in other galaxies. The third model only uses the known stellar mass components and is based on the Modified Newton Dynamics (MOND) theory. 

Our results indicate that the DMD model is comparable in accuracy to the NFW and MOND models and fits the data better at large radii where the rotation curve declines but has the largest errors. For the NFW model we obtain a virial mass M(vir)=(6.5±0.3)×10^11M⊙ with concentration parameter c=14.5, that is lower than what is typically reported. In the DMD case we find that the MW mass is M(d)=(1.6±0.5)×10^11M⊙ with a disk's characteristic radius of Rd=17 kpc.

Francesco Sylos Labini, et al., "Mass models of the Milky Way and estimation of its mass from the GAIA DR3 data-set" arXiv:2302.01379 (February 2, 2023) (accepted for publication in The Astrophysical Journal).

Physics Needs Better Literature Reviews

One of my favorite physicists, Stacy McGaugh, reacting to a tweet expressing the same opinion by another of my favorite physicists, Sabine Hossenfelder, bemoans a cultural and institutional problem with the fundamental physics community that I agree is a serious one. 

What is it?

Physicists routinely publish papers that fail to review the literature sufficiently to identify the fact that previous published work already rules out, disproves, or contradicts the hypotheses that they are advancing in their papers.

It is a standard and almost universal practice that pretty much every thesis, dissertation, and published physics paper (other than a very short letter preliminarily reporting a very narrow measurement or result before a full length analysis of the results can be published) contains some review of the literature that brings the reader to the point of scientific knowledge where the matters being addressed by the authors in the new thesis, dissertation, or paper begins.

But, in many cases, this literature review is half-hearted and perfunctory, and misses key prior work relevant to the new paper.

For example, one of my pet peeves is when a paper says that their proposal is "well motivated" by concepts developed decades earlier that have later been found to be deeply flawed.

This isn't a "mortal sin". The physics literature is vast and it grows every week. Not everyone in the discipline can devote the time that I do to reading every abstract in a whole range of related fundamental physics categories every day when it comes out on arXiv. And, there are multiple ways of looking at a problem that can make identifying relevant papers challenging (the same issue comes up in doing patent and trademark searches, or searching for precedents related to a legal issue).

But, if you are going to be advancing a new hypothesis in this field, you really should do a proper literature review (and more generally, you should really know the literature relevant to your work from multiple perspectives) before advancing theories that are contradicted by other observational evidence or theoretical considerations that you don't mention or engage with in your paper.

You don't have to agree with everything else that has ever been published. Sometimes previously published papers are incorrect and you are right. But when that happens, rather than ignoring what previously published papers have to say, you really should engage with prior contradictory papers and explain why you think that their observations or analysis is flawed or inapplicable, and thus doesn't actually contradict your work.

You don't necessarily have to spell out the contradictions or flaws of the prior work in full in every new paper in a series of papers developing an idea. It is sufficient to do it once in your first paper identifying what you believe is a flaw in prior work and then to cite that that discussion, incorporating it by reference and with a brief mention, in later papers. But that is very different from ignoring contradictory prior work entirely.

If the authors of physics papers did more diligent and comprehensive literature reviews (and peer reviewers did a better job of insisting on better quality reviews of the literature which would catch both many innocent omissions and many cases where prior contradictory work is willfully ignored), the quality of the papers that did get published would be greater. This is because a lot of speculative garbage papers that ignore known insurmountable obstacles to their work would be dropped before they were presented.

Mirror Cosmology Recapped

Here is a recap, all in one place, of work on mirror cosmology with an anti-matter universe before the Big Bang that is a mirror of our own and our own matter dominated universe that I've previously blogged, stripped of (probably wrong) speculations about dark matter and right handed neutrinos:

We argue that the Big Bang can be understood as a type of mirror. We show how reflecting boundary conditions for spinors and higher spin fields are fixed by local Lorentz and gauge symmetry, and how a temporal mirror (like the Bang) differs from a spatial mirror (like the AdS boundary), providing a possible explanation for the observed pattern of left- and right-handed fermions. By regarding the Standard Model as the limit of a minimal left-right symmetric theory, we obtain a new, cosmological solution of the strong CP problem, without an axion.

Latham Boyle, Martin Teuscher, Neil Turok, "The Big Bang as a Mirror: a Solution of the Strong CP Problem" arXiv:2208.10396 (August 22, 2022). The body text states:

In a series of recent papers, we have argued that the Big Bang can be described as a mirror separating two sheets of spacetime. Let us briefly recap some of the observational and theoretical motivations for this idea.

Observations indicate that the early Universe was strikingly simple: a fraction of a second after the Big Bang, the Universe was radiation-dominated, almost perfectly homogeneous, isotropic, and spatially flat; with tiny (around 10^−5) deviations from perfect symmetry also taking a highly economical form: random, statistically gaussian, nearly scale-invariant, adiabatic, growing mode density perturbations. Although we cannot see all the way back to the bang, we have this essential observational hint: the further back we look (all the way back to a fraction of a second), the simpler and more regular the Universe gets. This is the central clue in early Universe cosmology: the question is what it is trying to tell us.

In the standard (inflationary) theory of the early Universe one regards this observed trend as illusory: one imagines that, if one could look back even further, one would find a messy, disordered state, requiring a period of inflation to transform it into the cosmos we observe.

An alternative approach is to take the fundamental clue at face value and imagine that, as we follow it back to the bang, the Universe really does approach the ultra-simple radiation-dominated state described above (as all observations so far seem to indicate).

Then, although we have a singularity in our past, it is extremely special. Denoting the conformal time by τ , the scale factor a(τ) is ∝ τ at small τ so the metric g^(µν) ∼ a(τ)^(2ηµν) has an analytic, conformal zero through which it may be extended to a “mirror-reflected” universe at negative τ.

[W]e point out that, by taking seriously the symmetries and complex analytic properties of this extended two-sheeted spacetime, we are led to elegant and testable new explanations for many of the observed features of our Universe including: . . . (ii) the absence of primordial gravitational waves, vorticity, or decaying mode density perturbations; (iii) the thermodynamic arrow of time (i.e. the fact that entropy increases away from the bang); and (iv) the homogeneity, isotropy and flatness of the Universe, among others.

In a forthcoming paper, we show that, with our new mechanism for ensuring conformal symmetry at the bang, this picture can also explain the observed primordial density perturbations.

In this Letter, we show that: (i) there is a crucial distinction, for spinors, between spatial and temporal mirrors; (ii) the reflecting boundary conditions (b.c.’s) at the bang for spinors and higher spin fields are fixed by local Lorentz invariance and gauge invariance; (iii) they explain an observed pattern in the Standard Model (SM) relating left- and right-handed spinors; and (iv) they provide a new solution of the strong CP problem. . . .

In this paper, we have seen how the requirement that the Big Bang is a surface of quantum CT symmetry yields a new solution to the strong CP problem. It also gives rise to classical solutions that are symmetric under time reversal, and satisfy appropriate reflecting boundary conditions at the bang.

The classical solutions we describe are stationary points of the action and are analytic in the conformal time τ. Hence they are natural saddle points to a path integral over fields and four-geometries. The full quantum theory is presumably based on a path integral between boundary conditions at future and past infinity that are related by CT-symmetry. The cosmologically relevant classical saddles inherit their analytic, time-reversal symmetry from this path integral, although the individual paths are not required to be time-symmetric in the same sense (and, moreover may, in general, be highly jagged and non-analytic).

We will describe in more detail the quantum CT-symmetric ensemble which implements (12), including the question of whether all of the analytic saddles are necessarily time-symmetric, and the calculation of the associated gravitational entanglement entropy, elsewhere.

Another paper discusses one of the earlier papers by the authors above and elaborates on the foundation of their work:

In a recent work, Turok, Boyle and Finn hypothesized a model of universe that does not violate the CPT-symmetry as alternative for inflation. With this approach they described the birth of the Universe from a pair of universes, one the CPT image of the other, living in pre- and post-big bang epochs. The CPT-invariance strictly constrains the vacuum states of the quantized fields, with notable consequences on the cosmological scenarios.

Here we examine the validity of this proposal by adopting the point of view of archaic cosmology, based on de Sitter projective relativity, with an event-based reading of quantum mechanics, which is a consequence of the relationship between the universal information reservoir of the archaic universe and its out-of-equilibrium state through quantum jumps. In this scenario, the big bang is caused by the instability of the original (pre)vacuum with respect to the nucleation of micro-events that represent the actual creation of particles.

Finally, we compare our results with those by Turok et al., including the analytic continuation across the big bang investigated by Volovik and show that many aspects of these cosmological scenarios find a clear physical interpretation by using our approach. Moreover, in the archaic universe framework we do not have to assume a priori the CPT-invariance like in the other models of universe, it is instead a necessary consequence of the archaic vacuum structure and the nucleation process, divided into two specular universes.

Ignazio Licata, Davide Fiscaletti, Leonardo Chiatti, Fabrizio Tamburini, "CPT Symmetry in Projective de Sitter Universes" arXiv:2002.07550 (February 18, 2020).

The universe before the Big Bang is the CPT reflection of the universe after the bang, so that the state of the universe does not spontaneously violate CPT. The universe before the bang and the universe after the bang may be viewed as a universe/anti-universe pair, created from nothing. The early universe is radiation dominated and inflationary energy is not required. We show how CPT selects a preferred vacuum state for quantum fields on such a cosmological spacetime. This, in turn, leads to a new view of the cosmological matter/anti-matter asymmetry[.]

Latham Boyle, Kieran Finn, Neil Turok, "The Big Bang, CPT, and neutrino dark matter" arXiv:1803.08930 (March 23, 2018).

Some of their key earlier papers by some of these authors (which I haven't yet read and don't necessarily endorse) are: "Gravitational entropy and the flatness, homogeneity and isotropy puzzles" arXiv:2201.07279, "Two-Sheeted Universe, Analyticity and the Arrow of Time" arXiv:2109.06204, and "CPT-Symmetric Universe" arXiv:1803.08928. 

In the multiverse, the universes can be created in entangled pairs with spacetimes that are both expanding in terms of the time variables experienced by internal observers in their particle physics experiments. The time variables of the two universes are related by an antipodal-like symmetry that might explain why there is no antimatter in our universe: at the origin, antimatter is created, by definition and for any observer, in the observer's partner universe. The Euclidean region of the spacetime that separates the two universes acts as a quantum barrier that prevents matter-antimatter from collapse.

Salvador J. Robles-Perez, "Restoration of matter-antimatter symmetry in the multiverse" arXiv:1706.06304 (June 20, 2017).

Cosmological inflation:

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10^−36 seconds after the conjectured Big Bang singularity to some time between 10^−33 and 10^−32 seconds after the singularity. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago). . . . It was developed further in the early 1980s. It explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the Universe. Many physicists also believe that inflation explains why the universe appears to be the same in all directions (isotropic), why the cosmic microwave background radiation is distributed evenly, why the universe is flat, and why no magnetic monopoles have been observed.

Magnetic monopoles are already a non-existent problem so in this respect, cosmological inflation is merely ruling out a rubbish theory with no observational support.

Galaxies Ten Billion Years Ago Look A Lot Like Galaxies Today

The LambdaCDM model expects galaxies to take longer to appear when they do and to evolve significantly over time scales of billions of years. But, the latest observations of galaxies as much as 10 billion years old suggest that galaxies then had basically the same dynamics that they do now

We study the dynamics of cold molecular gas in two main-sequence galaxies at cosmic noon (zC-488879 at z≃1.47 and zC-400569 at z≃2.24) using new high-resolution ALMA observations of multiple 12CO transitions. For zC-400569 we also re-analyze high-quality Hα data from the SINS/zC-SINF survey. 

We find that (1) Both galaxies have regularly rotating CO disks and their rotation curves are flat out to ∼8 kpc contrary to previous results pointing to outer declines in the rotation speed Vrot; (2) The intrinsic velocity dispersions are low (σCO≲15 km/s for CO and σHα≲37 km/s for Hα) and imply Vrot/σCO≳17−22 yielding no significant pressure support; (3) Mass models using HST images display a severe disk-halo degeneracy: models with inner baryon dominance and models with "cuspy" dark matter halos can fit the rotation curves equally well due to the uncertainties on stellar and gas masses; (4) Milgromian dynamics (MOND) can successfully fit the rotation curves with the same acceleration scale a0 measured at z≃0. 

The question of the amount and distribution of dark matter in high-z galaxies remains unsettled due to the limited spatial extent of the available kinematic data; we discuss the suitability of various emission lines to trace extended rotation curves at high z. Nevertheless, the properties of these two high-z galaxies (high Vrot/σV ratios, inner rotation curve shapes, bulge-to-total mass ratios) are remarkably similar to those of massive spirals at z≃0, suggesting weak dynamical evolution over more than 10 Gyr of the Universe's lifetime.

Federico Lelli, Zhi-Yu Zhang, Thomas G. Bisbas, Lingrui Lin, Padelis Papadopoulos, James M. Schombert, Enrico Di Teodoro, Antonino Marasco, Stacy S. McGaugh, "Cold gas disks in main-sequence galaxies at cosmic noon: Low turbulence, flat rotation curves, and disk-halo degeneracy" arXiv:2302.00030 (January 31, 2023) (Accepted for publication in Astronomy and Astrophysics).