Category: human evolution

Neanderthals are Homo sapiens

January 4, 2026 • 12:15 pm

UPDATE:  I can still see the viewable-by-all post of David Hillis; perhaps you have to be on Facebook yourself to read it. Here is the full text:

“Joao Zilhão, an archaeologist at the University of Lisbon, noted, with a trace of sarcasm, that the push to classify Neanderthals as a separate species frequently arises from a reluctance, especially among geneticists, to fully accept them as a geographically distinct, but interbreeding, branch of humanity.”
Exactly. Neanderthals were a geographically distinct population of Homo sapiens, rather than a distinct species. The two populations interbred extensively, and many modern people (including me) have both as ancestors.
If pure Neanderthals were around today, no one would call them a different species, which would be considered highly insulting and racist. Why does the fact that we interbred them to extinction (actually intergradation) change that? Given that much of modern humanity carries Neanderthal genes in their genomes, it is time to stop making this misleading distinction.
Neanderthals are Homo sapiens, too.
***********************************************
Additional update by Greg Mayer: There was a good discussion of this issue on WEIT last June. Jerry, Matthew, and I all supported the single species view in the OP, and in the comments two prominent paleoanthropologists, John Hawks (University of Wisconsin-Madison) and Chris Stringer (British Museum (Natural History)) joined the discussion. Hawks (who agrees with Hillis and your WEIT authors) noted that there are explanations for reduced introgression on the X other than infertility of hybrids, while Stringer maintained that Neanderthals and moderns are distinct species. Interested readers should take a look at that post.
************************************************

For a long time I’ve maintained that Neanderthals, which most anthropologists seem to think are a species different from Homo sapiens, in fact constituted a population that was H. sapiens. That, at least, is a reasonable conclusion if you use the Biological Species Concept, which defines populations as members of the same species if, when they meet under natural conditions in nature, can interbreed and produce fertile offspring. And we know that’s true of  Neanderthals and “modern” H. sapiens, because we carry some Neanderthal genes (I have some), and that means the two groups hybridized and that the hybrids backcrossed to our ancestors—and were fertile.

The bogus “species” is known to some as Homo neanderthalensis, which I reject. I have no objections, however, to Neanderthals being called a “subspecies,” or Homo sapiens neanderthalensis, as a subspecies is just a genetically differentiated population that lacks reproductive barriers from other populations.

The four or five “species” of giraffes that have recently been “recognized” are in fact just like Neanderthals and modern humans: bogus entities said to be “real species”; but in the case of the giraffes they don’t meet in nature so we can’t test their ability to interbreed in the wild. But they can do in zoos (and produce fertile offspring). There is likely only one species of giraffe. You cannot rationally separate species that live in different places by their DNA divergence alone. Those who love to divide up species for any reason whatsoever are known as “splitters.”

I’m glad to see that David Hillis, a widely-respected evolutionary systematist at UT Austin, agrees with me. Here’s his post on Facebook about the topic, prompted by an article in the NYT.

Earliest evidence for humans making fire: 400,000 years ago

December 14, 2025 • 10:50 am

Although, as the authors of this new Nature article note, there is some evidence of human fire use in Africa going back 1.6 million years, they don’t consider the evidence definitive because “the evidence for early fire use is limited and often ambiguous, typically consisting of associations between heated materials and stone tools.”   They also note that there is more direct evidence but it’s quite recent:

. . . . direct evidence of fire-making by pre-Homo sapiens hominins has, until recently, been limited to a few dozen handaxes from several French Neanderthal sites, dating to around 50 ka, that exhibit use-wear traces consistent with experimental tools that were struck with pyrite to create sparks.

In this paper the authors investigate a site in Sussex, dated about 400,000 years ago, that has several lines of evidence suggesting regular use of fire, and controlled use, since there were materials like pyrite that could be used to strike sparks.  Note that the paper considers this the earliest evidence for making fire, not simply using fire.  The authors consider their work to provide pretty definitive evidence of fire-making and fire use in H. sapiens. (Note that we are the only species to use fire.)

Click the headline below to read the article, or you can find the pdf here.

The evidence came from an unused clay pit in the Breckland area of Suffolk, with deposits of clay and silt as well as human artifacts like hand axes. The evidence for persistent fire use at this site (the authors suggest at least two groups of humans, and comes from five observations and experiments. I’ve put them below under the letters.

a.) Red clayey silt (RCS) in the layers, silt that seems to have required prolonged heating to form. Here’s what it looks like.  The unexcavated section is in the top photo, and the bottom is the partly excavated area which is an enlargement of the box in (a). I’ve put a red arrow in (a) at the RCS layer thought to reflect heating of the sediments by the presence of “hearths”: areas where cooking or other uses of fire regularly took place. The layer is more obvious in the bottom photo:

The authors say that the red layer reflecs heating or sediments containing iron:

The reddening is attributable to the formation of haematite—a mineral produced through heating of iron-rich sediments. Its distribution is homogeneous and not associated with particular microfacies or voids, indicating that it was preserved in situ.

b.) Experimental heating of the non-red sediments. The authors showed that the magnetic properties of material in the RCS differ markedly from unheated “control” samples of material taken from the lower layer (“YBCS” in second photo above). But by heating the YCBS layer extensively, it assumed some of the magnetic properties of the RCS, suggesting that the RCS involved heating of clays by fire. As they say (bolding is mine):

Three samples were taken from the RCS and two from the adjacent YBCS, which served as unheated control samples. The magnetic properties of the RCS (Supplementary Information, section 5) differ markedly from those of the unheated control samples, exhibiting elevated levels of secondary fine-grained ferrimagnetic and superparamagnetic minerals of pyrogenic origin, unlike the control samples. To assess whether these characteristics could result from heating, a series of experiments of single and multiple heating events of varying durations, was conducted. The aim was to determine whether the reddening could have arisen from one or multiple heating events, as repeated, localized burning is more typical of human than natural fire events (S.H. et al. manuscript in preparation).

The closest experimental analogue in terms of the minerology and grain size distribution, was observed after 12 or more heating events, each lasting 4 h at temperatures of 400 °C or 600 °C. Although the archaeological samples exhibit substantially lower magnetic susceptibility values, this may result from post-depositional mixing with unheated illuviated clay. Overall, the experiments indicate that the magnetic properties of the RCS result from an indeterminate number of short-duration heating events, consistent with repeated human use (Fig. 3).

Note that prolonged heating—nearly 50 hours of heating at 400-600 degrees C, was required to approximate the magnetic properties of the presumed fire-use layer.  This suggests also that the heating did not reflect wildfires, but repeated, localized, and intentional burning.

c.) Infrared spectroscopy of heated control samples changed in infrared absorbtion spectra of the “control” samples, making it closer to that of the presumed hearth layer of RCS.

d.)  The area contained four handaxes that showed marks of heat-shattering.  Here is a picture of a handaxe with “closeup of fractured surface caused by fire.”:

Presumably this is based on experiments using recently made handaxes, with some treated by fire and then compared to unheated controls.

e.) Fragments of pyrite were found in the heated area, and pyrite  is used with flint to produce fire (before that, people presumably had to get fire from lightning burns and somehow preserve it). Moreover, pyrite was not found in this locality; the nearest accessible mineral was about 15 km away, suggesting that people picked it up and brought it to the site to strike against flint (flint was also found in the area). As the authors note:

The occurrence of pyrite at Barnham warrants further consideration. Pyrite is a naturally occurring iron sulfide mineral that can be struck against flint to produce sparks to ignite tinder. Its use for this purpose is well documented in ethnographic accounts worldwide. Pyrite has been recovered from European archaeological sites dating from the late Middle Palaeolithic to the historic periods, occasionally bearing wear traces consistent with use for fire-making and, in some cases, found in association with flint striking tools.

Here are some fragments of pyrite; caption is from paper:

(from paper): b, Fragment of pyrite found on the surface of palaeosol in Area IV(6). c, Fragment of pyrite from palaeosol in Area VI, found in association with concentrations of heated flint.

e.) The heated sites were located in areas amenable to prolonged fire use. This is weak evidence, but I present it nevertheless. From the authors:

Notably, all three sites occupy marginal locations, away from the main river valleys and associated with small ponds or springs. In the absence of caves, these locations probably provided safer, more sheltered environments for domestic activities. Taken together, these findings present a strong case for controlled fire use across the Breckland region during MIS 11.

The upshot:  We often forget that any meat eaten by people before the advent of cooking would have to be raw, and raw meat is tough and, at least to us, somewhat unpalatable. (I do like a very rare steak, as well as steak tartare, though.) But our ancestors didn’t grind up meat, though they may have pounded it to make a kind of raw Pleistocene schnitzel. By making meat more palatable, cooking would promote eating more of it, and that itself could change the selective pressures on humans, giving them the extra nutrients they’d need if they were to evolve big brains (brains use a lot of energy!).  This is one (disputed) theory for a rapid increase of human brain size that lasted between 800,000 and 200,000 years ago, though brain size was also getting bigger, albeit at a slower pace, before then. Cooking has also been suggested to have changed human social behavior (and perhaps social evolution), with pair bonding and mutual aid increasing as a way to gather, store, and protect food that needed to be cooked. And more complex social behavior could itself have promoted the evolution of larger brains to figure out how to regulate and get along in your small social group.

These theories, while suggestive, really should be downgraded to “hypotheses,” since there isn’t much evidence to support them—only correlation and speculation. However, they are interesting to contemplate, even if we never can get strong evidence for them.  At the end of the paper, the authors do seem to sign onto some of these, but not strongly.

The kernel of this paper is the several lines of evidence that do, to my mind, support the idea that humans were making and using fire at least 400,000 year ago.  Here’s what the authors say about the advantages, evolutionary and otherwise, of controlling fire:

The advantage of fire-making lies in its predictability, which facilitated better planning of seasonal routines, the establishment of domestic sites in preferred locations and increased structuring of the landscape through enculturation. Year-round access to fire would have provided an enhanced communal focus, potentially as a catalyst for social evolution. It would have enabled routine cooking, could have expanded the consumption of roots, tubers and meat, reduced energy required for digestion and increased protein intake. These dietary improvements may have contributed to increase in brain size, enhanced cognition and the development of more complex social relationships, as articulated in the Social Brain Hypothesis. Moreover, controlled fire use was instrumental in advancing other technologies, such as the production of glues for hafting. The widespread appearance of Levallois points from Africa to Eurasia by MIS 7 (243–191 ka), often interpreted as spear-tips, provides strong evidence of effective hafting. This interpretation is supported by use-wear evidence and the identification of heat-synthesized birch bark tar as a stone tool adhesive.

Human and chimp genome comparison: apples and origins

December 7, 2025 • 10:00 am

How much genetic difference separates us from our closest relatives? The conventional wisdom about humans and our closest ape relatives (chimps and bonobos) is that we share 98% of our DNA. That’s a big similarity, and implies that if we lined up our genomes side by side, only about 2 out of 100 DNA bases would differ. This figure is often used to show that we have only a tiny genetic difference from our closest relatives. To quote W. S. Gilbert of Gilbert and Sullivan, “Darwinian man, though well-behaved, at best is only a monkey shaved.”  Well, the differences go farther than mere shaving.

The “98% similarity figure” is wrong. And it’s wrong for several reasons. First, most ape genomes (chimps, gorillas, orangs, etc.) have not been as thoroughly sequenced as was the human genome. A lot of the data that went into the 98% figure was missing.  Second, you can’t just compare genomes by lining them up and looking for differences in base pairs at similar sequences.

Why not? Because the notion of “similar sequences” is ambiguous and, sometimes, meaningless. Since we diverged from our ape ancestors, there have been a lot of changes in every species’ DNA that prohibit us from simply “lining up the genomes”.  Transposable elements have invaded some species but not others, bits of the DNA have been duplicated, so there are species that have sequences that are not homologous. Bits of the genome have been inverted (turned around and reinserted), causing big differences in sequence in previously similar sequences. Further, pieces of the DNA have been moved from one chromosome to another, so DNA sequences previously in the same place are now in another place, leading to a difference in total sequence.

All this leads to a substantially greater DNA divergence between humans and chimps than the 98% figure.  These extra genomic differences were sussed out by Yoo et al. in a Nature paper  from April of last year that you can read by clicking below (or find the pdf here).They did a much improved job in sequencing six of our ape relatives: the chimp (Pan troglodytes), bonobo (Pan paniscus), Western gorilla (Gorilla gorilla), Bornean orangutan (Pongo pygmaeus), Sumatran orangutan (Pongo abelii), and the siamang (Symphalangus syndactylus), an endangered species of gibbon from SE Asia.

First, the authors give a revised set of divergence times based on DNA differences between living species.  The human vs. chimp/bonobo species, for example, split from their common ancestor about 5.5-6.3 million years ago (mya), roughly in line with previous estimates. The divergence between humans and other African apes (gorillas) occurred between 10.6 and 10.9 mya, and that between humans and orangutans about 18.2-19.6 mya.

There is a ton of genomic information in the paper, including a lessening of the similarity between humans and chimps, but also specific information about what genes and regulatory bits of DNA differ among species. These differences suggest some some intriguing future research. I’ll mention just a couple, but will refer you instead to a long tweet below which shows why the human-chimp differences have increased. It’s an excellent tweet that you can read pretty quickly, though it doesn’t detail all the many differences that the researchers describe in the Nature paper, which is exhausting for those outside the field. There are also genes whose sequences changed very rapidly, suggesting that they were acted on by natural selection.

There are a gazillion sequence and structural differences revealed among the species, including 229 bits of ape DNA (all species) that have evolved rapidly and are thus candidates for natural selection. The paper also reveals parts of the DNA that have evolved especially rapidly in the human lineage since we split from chimps/bonobos. These regions are called HAQERS, and could be candidates for the Holy Grail of such work: seeing “what makes us human”. But that question is a bit misguided.

Nevertheless, the authors found one gene, ADCYAP1, that “is differentially regulated in speech circuits.” The implication is that the changes may have something to do with why humans are the only ape with syntactic spoken language, but that gene does a lot of other stuff, too, so I don’t take that implication seriously. The FOXP2 gene, which evolved rapidly in the modern human genome relative to other species, has mutations that impede people’s ability to speak, and I well remember when it was touted as “the language gene” that enabled humans to speak. But further research showed that the accelerated human evolution of the gene was an artifact, and that the normal function of the gene is manyfold, so nobody these days takes FOXP2 seriously as the “speech gene”. All claims should be regarded as caveat emptor.

There are also several genes that are not only unique to humans, but are “associated with human evolution of the frontal cortex”, suggesting these account for our big brains. The photo below comes from the tweet shown next, and its caption comes from that tweet. (The average chimp brain is about 400 g in mass—less than a third the mass of the human brain, which weighs in at 1300-1400 g in adults.)  Again, caveat emptor with regard to the two specified genes.

Figure 3. Radiograph illustrating cranial expansion in the human lineage, which is associated with increased neocortical growth – Chimpanzee skull (left), Modern Human skull (right).

Other genes that differ strongly among ape species involve those producing immunoglobulin, major histocompatibility products (MCH) and T-cell receptors, but especially immunoglobulin genes—involved in production of antibodies. Why have these evolved so rapidly within apes? Your guess is as good as mine, but suggests that reaction to antigens was an important element of ape evolution.

Here is the authors’ summary, and most of the paper will be of interest only to geneticists familiar with the argot (not necessarily me):

The complete sequencing of the ape genomes analysed in this study significantly refines previous analyses and provides a valuable resource for all future evolutionary comparisons. These include an improved and more nuanced understanding of species divergence, human-specific ancestral alleles, incomplete lineage sorting, gene annotation, repeat content, divergent regulatory DNA and complex genic regions as well as species-specific epigenetic differences involving methylation. These preliminary analyses revealed hundreds of new candidate genes and regions to account for phenotypic differences among the apes. For example, we observed an excess of HAQERS corresponding to bivalent promoters thought to contain gene-regulatory elements that exhibit precise spatiotemporal activity patterns in the context of development and environmental response99. Bivalent chromatin-state enrichments have not yet been observed in fast-evolving regions from other great apes, which may reflect limited cross-species transferability of epigenomic annotations from humans. The finding of a HAQER-enriched gene, ADCYAP1, that is differentially regulated in speech circuits and methylated in the layer 5 projection neurons that make the more specialized direct projections to brainstem motor neurons in humans shows the promise of T2T genomes to identify hard to sequence regions important for complex traits. Perhaps most notably, we provide an evolutionary framework for understanding the about 10–15% of highly divergent, previously inaccessible regions of ape genomes. In this regard, we highlight a few noteworthy findings.

The importance of the paper for now seems to be the presentation of the sequences and their differences rather than explaining the differences or their significance in ape adaptations—especially in humans—for studying adaptive hypotheses involves a lot of work for each single region that differs among species or evolved quickly. Nevertheless, useful questions have been raised—like why genes involved in the immune response changed so rapidly—that will be subject to future work.

I am not sure who runs the Origins Unveiled site dealing with evolutionary anthropology, but based on the clarity of the tweet below from that site (click on screenshot to see the tweet in situ), it deserves more followers. It’s only about a year old, which may explain the follower issue.

This tweet from September of this year explains why the 98% similarity between humans and chimps drops to 84.7% when you take translocations, inversion, duplications, insertions, and other genomic rearrangements into account. And these rearrangements are not necessarily trivial, for duplications can lead to divergent gene families, and insertions can act to regulate genes in a new way.

Again, click below and read; it’s short and lucid:

I’ve shown one figure from the tweet above: the brain differences. Below is another figure showing how the 99% similarity between humans and chimps has traditionally been calculated, requiring alignment of nearly identical but perhaps slightly different bits of DNA. All captions come from the tweet. This figure shows how they line up chimp and human sequences (you see the gross similarity), but also that here there’s been a single nucleotide substitution in one of the two lineages, rendering this sequence 92.3% similar. (This is a made-up sequence for purposes of illustration.)  When you did that with the whole genome comparison based on earlier data, you got about a 2% difference. The problem, as I said, is that we didn’t have great chimp (or any ape) sequences and there are parts that you simply couldn’t line up this way. And those parts, when compared among species, increase the genetic difference between us and our closest relatives.

Figure 1 — Simplified Mock Alignment Illustrating Nucleotide Sequence Similarity Between Chimpanzee and Human Genomes. Out of 13 positions, one substitution (single-nucleotide variant, circled in red) results in ~92.3% DNA similarity. This example demonstrates the methodology behind the misleading 98–99% human-chimpanzee DNA similarity figures.

Below is another figure showing how various rearrangements, insertions, deletions, and translocations reduce similarity, but I’ll show only four of the six parts of the figure, giving the captions for a-d. You can see how these changes make humans and chimps less genetically similar than previously thought (again, captions come from the tweet; click to enlarge).  These are also “mock alignments” meant for purposes of illustration, but they do show the kind of thing seen in the Yoo et al. paper:

Figure 2 — Simplified Mock Alignments Illustrating Structural Variation Between Chimpanzee and Human Genomes. Note: Structural variants are not taken into account when calculating the 98–99% Chimpanzee-Human DNA similarity figures.
( a) Insertions and deletions contributing to sequence divergence. Out of 34 positions, 3 indels (insertions circled in orange; deletions in yellow) result in ~91.2% DNA similarity. Note: These indels are relative, as without a suitable outgroup (i.e. gorilla), an insertion in one genome appears as a deletion in the other.
(b) Duplication contributing to sequence divergence. Out of 34 positions, a duplication of 12 bases (duplicated segment encircled in blue; original in purple) results in ~64.7% DNA similarity.
(c) Inversion contributing to sequence divergence. Out of 34 positions, an inversion of 11 bases (encircled in green) results in ~67.6% DNA similarity. Note: Although bases may match within the inverted region, they do not contribute to sequence similarity due to misalignment. Without a suitable outgroup (i.e. gorilla), it is unknown whether the inversion occurred on the chimpanzee or human genome.
(d) Translocation contributing to sequence divergence. Out of 34 positions, a translocation of 20 bases (encircled in brown) results in ~41.2% DNA similarity. Note: A translocation is a DNA segment that has been “copy and pasted” or “cut and pasted” from another part of the genome.

So, when you hear that we’re nearly genetically identical to our closest relatives, just say, “Wait a tick. Not all that identical.” We have about 15% difference in sequence, which is not trivial.

UPDATE: I’m aware now that creationists and IDers have been using this 85% to cast doubt on human evolution, our place in the ape family tree, and whether evolutionists are honest.  This is bogus: the 85% vs. 98% depends on two different methods of calculating similarity. Which ever method you choose (alignment vs. total genomic similarity), the same family tree of the great apes appears, with chimps/bonobos our closest ancestors, then gorillas a bit more distance, and then orangutans, and then other apes.  The point of this post is not to cast doubt on human or ape evolution, but to show different ways of calculating genetic similarity.

The sad fate of human evolutionary biology in Australia

October 20, 2025 • 11:30 am

Although the times when Homo sapiens reached Australia are under revision, the latest data suggests that they arrived between 45,000 and 60,000 years ago—about the time that our species left Africa for parts east.  And although changes in water levels made it easier to get to Australia by water then now humans still had to use boats of a kind. What kind of boats they used is a mystery.

But there are a number of other questions that remain about the colonization of Australia. How many colonizations were there? Did any of the colonizing H. sapiens carry genes from H. erectus?  How much genetic material in the colonists came from Denisovans? (There are some suggestions of both of these possibilities based on aspects of skull morphology.) Did the aboriginal colonists evolve in the last 50,000 years? Regardless of how many colonizations were there, what was the population structure of indigenous people since they arrived here? And based on artifacts, what were the cultures of the early indigenous people?

All of this can be studied not just by digging up skull or artifacts, but also now by genetic testing: looking a “fossil DNA” from specimens. Unfortunately, what is happening in the U.S. and Canada is also happening in Australia: people who identify as “aboriginal” (and you can do this by self-identification, not necessarily by ancestry) are preventing the scientific study of skulls and artifacts by claiming that fossils or artifacts were from their ancestors, even though, as in the U.S., determination of “ancestry” of fossil remains can be dubious. Further, some indigenous people living today want to know their history, but are blocked by the reburial policy adopted by the some state governments. Further, many people recognized as aboriginals today also claim that their ancestors have been in Australia forever,  and don’t want data that dispels the myth.

The article below, in Palladium Magazine, recounts the tremendous loss to science of specimens that, even without firm ancestral documentation, get reburied without study.  This is even true of material found in the Willandra Lakes region of New South Wales, which is in fact a World Heritage Site and contains important human remains:

The Willandra Lakes Region is a World Heritage Site in the Far West region of New South Wales, Australia. The Willandra Lakes Region is the traditional meeting place of the Muthi Muthi, Ngiyampaa and Paakantyi Aboriginal peoples. The 2,400-square-kilometre (930 sq mi) area was inscribed on the World Heritage List at the 5th Session of the World Heritage Committee in 1981.

The Region contains important natural and cultural features including exceptional examples of past human civilization including the world’s oldest evidence of cremation. . . .’

. . . . Aboriginal people lived on the shores of the Willandra Lakes from 40,000 to 35,000 years ago. It is one of the oldest known human occupation sites in Australia. There is abundant evidence of Aboriginal occupation over the last 10,000 years.

Interesting and controversial fossils like WLH-50 have been found in Willandra, but now many fossils are being reburied, and fossils found weathering out of that region cannot be excavated or studied scientifically.

Click the headline to read the article:

I’ll give some quotes to apprise you of the situation. In toto, it seems that the study of human evoution (not, as the title implies, “evolutionary science”) is dying in Australia. But there are many other creatures besides humans, including the many marsupials.

Quots from the article are indented, while bold headings are mine:

Possible evolutionary change from the earliest inhabitants until now:

As more fossilized remains were discovered [after WWI], sometimes hidden within collections of recent bones, comparisons could be drawn between ancient Australians and the ones first encountered by Europeans. While sharing some skeletal similarities with recent populations, ancient individuals were often distinguished by “heavy-boned faces, enormous teeth and jaws, receding foreheads and flask-shaped skulls.” The mosaic of modern and archaic traits, seen to a lesser degree in contact-era skulls, emphasized the importance of these fossils to evolutionary history. The largest collections included Kow Swamp (c. 20,000 years old), Coobool Creek (c. 14,000 years old) and Willandra Lakes (c. 43,000 to c.14,000 years old).

One exceptional specimen was designated “Willandra Lakes Human 50,[WLH-50] also known as Garnpung Man. It shared traits with Javan Homo erectus and was more similar to ancient humans from Skhūl Cave in Israel than contact-era Australian foragers. At an estimated 26,000 years old, it may have had significantly more Denisovan ancestry than the 2-4% seen in recent Melanesians and Australian foragers.

The morphological variability seen in the fossil record led some researchers to hypothesize multiple migrations into Australia, with some genes coming from Homo erectus and some from ancient Chinese Homo sapiens. Others argued for local adaptation of a single Homo sapiens founding population. This debate featured significantly in the global discourse between proponents of “multiregional evolution,” which claims that modern Homo sapiens evolved simultaneously in multiple parts of the world, versus the “Recent Out of Africa” theory, which holds that Homo sapiens first evolved in Africa and then spread into Europe and Asia, replacing older human species.

What made these collections particularly valuable was their status as a comparative series. The ability to compare a group’s average morphology across eras and regions allowed scientists to track evolutionary changes and adaptations in ways that singular remains could not.

Who counts now as “aboriginal”? Bolding in the text below is mine.

Today, three separate groups are often conflated under the single term “Aboriginal.” These are:

  1. The ancient humans who first settled the continent.
  2. The contact-era foragers encountered by British colonists.
  3. The citizens currently classified as “Aboriginal” by the government.

This third category was formed when Australia’s 1967 constitutional referendum empowered the federal government to make laws for people of the “aboriginal race.” The government subsequently changed its definition of Aboriginal from requiring over 50% forager ancestry to a new standard based on self-identification, any degree of biological descent, and community recognition. This pivotal change meant even those with minimal forager ancestry could join the Aboriginal “class.” A separate legal class, “Torres Strait Islanders,” was eventually split off, with both classes now subclasses of the “Indigenous” slash “First Nations” class.

Before 1967, “Aboriginal” was a legal class with restricted rights. To avoid stigma, many mixed-descent Australians kept their forager ancestry a secret. But as membership criteria relaxed, and additional rights and privileges granted, more people publicly claimed forager ancestry. The Indigenous population exploded and is still growing faster than birth rates can explain. This is the result of people joining the class as adults, sometimes inspired by family legends or personal conviction. Also notable is that most Indigenous-class Australians marry non-Indigenous-class partners, but 90% of children from these unions are assigned Indigenous at birth. Archaeologist Josephine Flood observes that “Many people who identify as Aboriginal have white skin, blue eyes, narrow noses and blond, brown or red hair. Others resemble Japanese, Chinese, Melanesians, Polynesians, or Afghans.” In 2015, a government official estimated that 15% of Indigenous citizens had no forager ancestry whatsoever. 

This of course means that many people can have a claim to have ancient aboriginal ancestry, and then bring lawsuits against scientists taking and studying skulls.  There need be no genetic evidence of ancestry to bring such suits, as the genetic ancestry has been muddied by state-specific laws that prevent the study and excavation of the skulls or DNA analysis.

Not all human remains or artifacts must be repatriated: WLH-50, for example, is still in the hands of scientists. But AI says this about laws, and I’ve verified the claims by looking at several other sites:

In Australia, laws prohibit the burial of Aboriginal ancestral remains, sometimes referred to as fossils, by anyone other than the relevant Aboriginal community with traditional or familial linkes to them.  The legal and ethical framework is centered on the principle of repatriation: the return of ancestral remains from museums, universities, and private collections back to their Traditional Owners for culturally appropriate care and reburial.

This system is governed by a combination of federal and state or territory legislation.

Reburials began en masse in the 1980s, though there were some that were earlier. Now, it seems, the Australian government, perhaps infused with a view of the “sacralization of the oppressed,” seems ready to rebury fossils and artifacts in view of simple and poorly documented claims.  And given the difference in time between modern aboriginals living in the same area as ancient aboriginals, the claim of “ancestry” giving one rights over fossils from tens of thousands of years ago seems weak, especially because no genetics is involved. But it’s strong enough to overrule the scientists:

By 1984, the massive Murray Black skeletal collection had been transferred following legal action by the Victorian Aboriginal Legal Service and, in 1985, remains of thirty-eight foragers were buried in a public ceremony in Melbourne’s Kings Domain park.

The movement now targeted fossilized remains with only tenuous connections to contact-era foragers. The ancient skulls from Eagle Hawk Neck and Mount Cameron West (c. 4260 years old) were transferred to the TAC in 1988 and cremated. In Victoria, the Coobool Creek collection was reburied in 1989, followed a year later by the Kow Swamp collection. In 1991, Alan Thorne voluntarily surrendered Mungo Lady, the first individual excavated at Willandra Lakes. During the handover, he implored the 3TTG (Three Traditional Tribal Groups) to preserve the fossils for future generations.

But as the voices of opposition grew weaker, the burials continued: in 2022, both Mungo Man and Mungo Lady were reburied, secretly. The final blow came in March 2025 when the rest of the Willandra Lakes collection, 106 fossilized individuals, was buried in an unmarked grave, despite a last-minute legal appeal from Gary Pappin, a local Mutthi Mutthi man, and efforts by archaeologist Michael Westaway, who compared it to the Taliban’s destruction of the Bamiyan Buddhas. As of this year, Australia’s human fossil record, as well as the biological history of many extinct contact-era populations, has been effectively erased.

The rationale for reburial is weak, and even involves the supernatural. Get a load of this:

In general, the activists won the war of words. They used language that bolstered ownership claims like “repatriation,” “return,” and “ancestors,” which implied already-proven connections. While scientists used rigorous but dry terminology, activists referred to bones as “our Old People” whose “spirits cannot rest,” claiming that the mere existence of museum collections caused unverifiable harms like “cultural trauma.” Opponents who accepted this linguistic frame found it hard to argue without appearing callous.

Michael Mansell soon took the campaign overseas, convincing European institutions to hand over remains they had acquired during the colonial period. By the 2000s, the removal movement had won widespread support from museums, governments, and even previously-opposed archaeologists. This shift in attitudes resulted in formal policies and funding that allowed the transfer of thousands of forager remains to Aboriginal-class organizations.

The upshot is indeed the dying of ancient human anthropology in Australia. Even new Willandra Lakes fossils, which are important ones, cannot be removed or studied:

Happily, local Aboriginal land councils have allowed a few accidental discoveries to be briefly studied and dated, such as Kiacatoo Man (c. 27,000 years old), the largest Pleistocene skeleton ever found in Australia. But no intentional excavations have taken place for decades. At the Willandra Lakes UNESCO World Heritage Site, fossilized skulls are occasionally observed eroding from the ground but study is forbidden and they soon disintegrate.

According to archaeologist Colin Pardoe in 2018, “The repatriation of skeletal collections has meant that student access to teaching collections containing Australian material has become almost impossible…. This has resulted in researchers moving into other fields or other parts of the world.” And Vesna Tenodi explains, “Replicas or even drawings cannot be displayed, or discussed, as that also is too offensive without ‘Aboriginal permission.’”

Replicas and drawings have been forbidden in the U.S. too, as Elizabeth Weiss documents. She wasn’t even allowed to photograph the boxes containing fossil bones found in the U.S.! The article continues

Other archaeologists note that “fieldwork in Australia essentially ground to a halt as much of the modern debate over the origins of modern humans was beginning to take shape.” Just as DNA analysis, 3D imaging, and other revolutionary techniques were entering the field, the fossil record of an entire continent was wiped clean. Only a handful of specimens were ever studied by geneticists. Archaeologist Steve Webb estimated that the Pleistocene series from Willandra Lakes contained 38 individuals suitable for DNA testing. But that analysis was never done and the window of opportunity has now closed.

This kind of “anthropological activism” has been extensively documented by Elizabeth Weiss  in other countries (see her books here), and the power of indigenous peoples to impede scientific study is strong. They have tried compromises in Australia, like allowing scientists to study remains over 7,000 years old, but these have failed. And there is virtually no possibility of compromise in the United States or Canada.

Now that these activists have acquired most of Australia’s human fossils and bones, they have expanded their removal and censorship campaigns to “include the return of cultural heritage materials, including objects, photographs, manuscripts, and audio-visual recordings.” Each concession leads to more expansive claims rather than resolution. They claim ownership over what questions can be asked about the past and the very words that can be used to ask them.

And the same script is being followed in Canada and the United States, with Indigenous-class activists reburying ancient remains and artifacts under NAGPRA legislation, censoring photographs, and even asserting ownership over dinosaur fossils based on creationist mythology. In 2017, the 9,000 year-old fossil Kennewick Man was buried after years of controversy. In Europe as well, museums and universities face shrinking collections and pressure to censor information.

Everyone agrees that the loss of ancient hominin fossils during World War II was a tragedy. Someday, hopefully, they will feel the same way about the artifacts and fossils currently being destroyed.

The future.  As the article notes, not every state government has bowed to these demands, and some museums are refusing to surrender their collections. Other people are trying to forge productive relationships between “colonists” and modern aboriginals to permit research, including DNA research.  More compromises could be forged that allow at least some scientific study, including extraction of DNA, which takes only a bit of earbone, before remains are reburied. But governments have been all too timorous to stand up to the increasingly strong demands of modern aboriginals to force reburial.  In the absence of demonstrating recent ancestral-descendant relationships between modern and older aboriginals, or to set cutoffs to allow study of older remains, science should trump mythology.  In the end, this seems to be more about power than anything else.

h/t: Coel, Luana

A Denisovan skull–at last!

June 24, 2025 • 9:00 am

JAC: Greg sent me some thoughts on the new hominin finds involving what used to be known as Denisovans. I suggested he put up his own post on these thoughts, and he kindly agreed. The result is below.

Greg has asked me to weigh in at the end, and I will, under the JAC initials. Except for that, credit for this post goes to Greg.

by Greg Mayer

In a recent pair of papers, Qiaomei Fu and colleagues show, via both DNA and protein analyses, that the skull known as “Dragon Man” from Harbin, China, is a Denisovan. The Denisovans, first identified in 2010 by DNA from a single finger bone from a cave in Siberia, are a long-separated (several 100 kya) lineage of humans that has interbred with anatomically modern humans and Neanderthals, leaving a fairly strong signature (ca. 6%) in the ancestry of modern humans from East Asia and the Pacific. Although several more Denisovans were identified by DNA after the first one, all were from very incomplete remains– until now.

The Harbin skull. CCA 4.0 https://doi.org/10.1016/j.cell.2025.05.040

The Harbin skull was first made known to science in 2018, and was named Homo longi in 2021. I have been able to access only the DNA paper, not the protein one, but Carl Zimmer gives a fine summary in the NY Times.

Zimmer notes that some scientists, including Chris Stringer of the British Museum (Natural History), are now using the name Homo longi, based on the Harbin skull, as the name for the Denisovans. John Hawks of the University of Wisconsin, pushed back on this, telling Zimmer “I’m pretty confident saying these are all Homo sapiens.”

Jerry, Matthew, and myself have discussed Neanderthals (or Neandertals) and Denisovans several times here at WEIT.

About 10 years ago, Jerry, I, and Hawks all agreed on all three forms (Neanderthal, Denisovan, anatomically moderns) being members of one interbreeding species. But when I read David Reich’s book and other papers about five years ago, I was impressed by the paucity of Neanderthal DNA on the X chromosome of moderns, suggesting that Haldane’s Rule had kicked in, and there was partial intrinsic isolation (probably sterility) of hybrids between Neanderthals and moderns. (Haldane’s Rule states that if there is partial reproductive isolation due to infertility or sterility of hybrids, it is the heterogametic sex—XY males in Homo— that is most affected.) So, my view now is that a few hundred thousand years of isolation had moved the Neanderthals and moderns measurably down the road to speciation, though obviously not completely.

My earlier view had been that the low percentage of Neanderthal DNA in moderns was due to social/historical factors, analogous to how there is little European/American Indian admixture in North America, even though there is no intrinsic isolation between these two groups. There’s probably still some social/historical factors involved in the Neanderthal/modern encounter, but part of the disparity in genetic contribution is due to some infertility in male hybrids. [JAC: This infertility is suggested by the observation that introgression of Neanderthal DNA into modern humans is less pronounced on the X chromosome than on the other chromosomes, or autosomes.]

As far as nomenclature goes, I’d be happy with them all being sapiens, but we should recognize that the differences between Neanderthals/Denisovans and moderns are greater, and of a different sort, than differences between the obvious geographic races that exist within modern humans today.

Hawks has a piece on his website, “The humanity of a new Denisovan“, in which he expands on his comments to Zimmer and goes much deeper into the issues of the history of Homo in the last million years; I heartily recommend it. His fourth figure (the second phylogeny) in particular provides a nice summary of his view of that history, including various episodes of interbreeding. He does not mention the distribution of Neanderthal DNA within the moderns’ genome (i.e., the paucity of it on the X), so I’m not sure if this has affected his thinking in any way. I’m hoping that Jerry will weigh in with his current thoughts on the significance, if any, of the distribution of Neanderthal DNA across the moderns’ genome.

JAC:  I’m in agreement with Greg (and Matthew, who I hope will also weigh in here) that “modern” sapiens, Denisovans, and Neanderthals should be considered members of the same biological species, Homo sapiens.  I don’t know how big the disparity between introgression of X-linked vs. autosomal DNA is with respect to modern human genomes, so I cannot judge if it is substantive evidence for some sterility (or inviability) of the hybrids between modern sapiens and Neanderthals. Since the sterility would have to be strong to even consider these two as different biological species, and because there is a sizable aliquot of Neanderthal DNA in many modern humans, the sterility could not have been nearly complete. (I don’t know if Denisovan DNA in modern humans show the same disparity between that from the X chromosome versus the autosomes. If it doesn’t show that, there’s no reason to split Denisovans off as a new species.).

At any rate, the biological species concept (BSC) regards two populations as members of the same species if they can hybridize when they encounter each other in nature and some of the hybrids are viable and fertile. To the extent that Neanderthals meet that requirement, I would say that they, too, are members of H. sapiens.  This kind of “splitting” of groups into different named species is pervasive in human paleobiology, as it is in some other groups, like giraffes, but to me rests on shaky grounds. People like to split human groups into new species, for you get a lot more attention if you can say you found a new species than if you say you simply found a new subspecies or population.

Matthew: The identification of the extraordinary ‘Dragon man’ skull with the Denisovan lineage is probably what most people expected, but is nonetheless an astonishing development, using protein profiles to establish evolutionary relationships (first suggested by Francis Crick in his 1957 ‘central dogma’ lecture, but he never imagined this could be done on a sample over 140,000 years old!). The issue is what we call the Denisovans – the skull was described as Homo longi, and paleoanthropologists, such as the Natural History Museum’s Chris Stringer, accept this, just as they accept Homo neanderthalensis for the Neanderthals. I agree with Jerry that from a biological point of view, these are all members of the same species, because of the existence of fertile hybrids (us!).

This was Chris’s reply to me on Bsky:

This is a link to the article he refers to.

There are two points that make me pause. First, the taxonomic powers that be are unlikely to change their collective minds on this (they haven’t shifted over H. neanderthalensis in the last decade or more, since the first Neanderthal genome was sequenced and the existence of introgression was established. It’s mildly irritating, but that’s the way it will be. Secondly, the points raised by Greg are interesting – we were separated from these lineages for hundreds of thousands of years, and during this time some striking morphological adaptations occurred. They clearly did not lead to the establish of biological species, although we have little grasp of morphological or genetic variation in these groups (all of which were composed of very small (tens of thousands at most), dispersed populations). The role of the X chromosome, as highlighted by Greg, suggests that all three lineages may have been on the way to speciation, although that process was stopped by the demise of the Denisovans and Neanderthals (whether it would have continued in the presence of introgression is another thing to consider).

Finally, our understanding of human evolutionary history is perpetually changing. Stephen Jay Gould used to rewrite his slides each year; I did the same, pretty much, until I found this on Twitter, back when it was good, and now use it in all my human evolution lectures (along with more serious stuff).

 

Fu, Q., P. Cao, Q. Dai, E. A. Bennett, X. Feng, M. A. Yang, W. Ping, S. Pääbo, and Q. Ji. 2025. Denisovan mitochondrial DNA from dental calculus of the >146,000-year-old Harbin cranium. Cell 188:1-8. pdf

Fu, Q., F. Bai, H. Rao, S. Chen, Y. Ji, E. A. Bennett, F. Liu, and Q. Ji. 2025. The proteome of the late Middle Pleistocene Harbin individual. Science in press. locked

Reich, D. 2018. Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past. Pantheon, New York

Oldest known Australian hominin fossils to be reburied

March 20, 2025 • 9:40 am

Once again we have a conflict between science and the unevidenced claims of superstition. This time it’s from Australia.

Some of the “Willandra lakes fossils” from New South Wales, which include the famous “Lake Mungo remains” (three sets of hominin fossils that are the oldest ones known from Australia), have been or are scheduled to be reburied without further study. You can guess why: the indigenous people claim that these are their ancestors, giving them, so they say, moral rights to do what they want with all ancient bones that are found. I first learned about it from the two tweets below, but had a lot of trouble finding any news. I suspect that the news has been suppressed by the media because any intimation that these fossils derived from ancestors in other places is abhorrent, violating their superstitions. As the Australian National Museum notes:

From an Aboriginal and Torres Strait Islander view of creation, people have always been in Australia since the land was created.

On mainland Australia, the Dreaming is a system of belief held by many first Australians to account for their origins. In the Dreaming all-powerful beings roamed the landscape and laid the moral and physical groundwork for human society.

Prior to the Dreaming there was a ‘land before time’ when the earth was flat. Ancestral beings moulded the landscape through their actions and gave life to the first people and their culture. No one can say exactly how old the Dreaming is. From an Indigenous perspective the Dreaming has existed from the beginning of time.

And that led to the situation that I saw in these two tweets:

I link to the petition below.

You can read about the Garnpung Giant, WLH-50, here, on a site by Peter Brown. (The fossil is called “Giant” because its head is unusually large). It hasn’t been studied much, but has already been reburied to satisfy the wishes of indigenous people. I truly wonder why many of the aboriginals (not all of them) prefer these fossils to be buried rather than studied, but, as I said, scientific study might show these fossils to themselves have been from “settler colonialists”!

Willandra Lakes Hominid 50 was recovered from a deflating land surface in the Garnpung/Leaghur Lake region of south-western New South Wales, with the first published report in Flood (1983). This skeleton has not been reliably dated, has not been formally described, and is probably pathological. These circumstances result in some unease over the extreme claims made about the relevance of WLH 50 to interpretations of the Australasian evolutionary sequence (Stringer 1992; Brown 1992; Stringer and Bräuer 1994). In particular WLH 50 regularly appears as a corner stone in arguments for evolutionary continuity between the Indonesian and Australian regions published over the last two decades (Thorne 1984; Wolpoff 1992, 1995; Thorne and Wolpoff 1992; Frayer et al. 1993; Frayer et al. 1994; Hawks et al. 2000) which is an unusual circumstance for an undescribed and poorly provenanced fossil.

Attempts to date WLH 50 have obtained controversial results. Initial attempts to obtain a radiocarbon date achieved a result much younger than expected. It is possible that the specimen was contaminated and material other than collagen was dated. It is also possible that the fossil is a lot younger than some people would like.

WLH 50 consists of a fragmentary cranial vault, with damage to the basal and temporal segments, some facial fragments, parts of an elbow joint and some smaller postcranial pieces. The most striking feature of the cranial vault, malar fragments and elbow is of great size. Although glabella is not preserved, maximum cranial length can be estimated (±3 mm) to 212 mm, with a maximum cranial breadth of 151 mm and maximum supraorbital breadth greater than 131 mm. These dimensions exceed the recorded Aboriginal range of variation (Brown 1989). Even with the pathologically thickened vault, discussed below, endocranial volume was approximately 1540 ml compared with the Holocene Aboriginal male mean of 1271 ml Brown (1992b) . The extremely large size of WLH 50 should be of some concern to those who argue that this skeleton is in some manner representative of ‘Late Pleistocene’ Australians (Thorne 1984; Wolpoff 1992, 1995; Thorne and Wolpoff 1992; Frayer et al. 1993; Frayer et al. 1994).

There’s more at the site linked above, but the large cranial vault made it especially imperative to study this specimen. Sadly, it’s now deteriorating below ground, thanks to the demands of the indigenous people.

As Wikipedia notes, this region has harbored humans for the last 40,000 years, some of the oldest H. sapiens fossils known. (Remember, the humans who populated the world left Africa roughly 70,000 years ago, and colonized Australia only 5,000 years after that). That makes these fossils especially important for scientific study.  But when they’re reburied, as all three of the major Lake Mungo fossils have been, no further study is possible, and the bones will be destroyed. And look at this:

In 1989, the skeleton of a child believed to be contemporary with Mungo man was discovered. Investigation of the remains was blocked by the 3TTG with the remains subsequently protected but remaining in-situ. An adult skeleton was exposed by erosion in 2005 but by late 2006 had been completely destroyed by wind and rain. This loss resulted in the Indigenous custodians’ receiving a government grant of $735,000 to survey and improve the conservation of skeletons, hearths and middens that were eroding from the dunes. Conservation is in-situ and no research is permitted.

At any rate, two readers managed to find two article on this from the ABC. The first one is from 2022, but the second is from this week, showing that the dispute is ongoing.

From 2022 (click to read):

An excerpt:

First Nations people with direct links to Australia’s oldest human remains say they should have the ultimate voting rights to re-inter the skeleton, not the federal Environment Minister.

The Willandra Lake Region, near Ivanhoe in the far Central West, is home to Mungo Man’s 42,000-year-old remains, the oldest in Australia and first recorded evidence of a ceremonial burying.

In 1974, Mungo Man’s body was removed from the ancient burial site, along with more than 100 other Aboriginal graves.

In 2017, the body was returned to the region but has remained in the Lake Mungo visitor centre.

JAC: It’s not there any more: Mungo Man and Mungo Lady were reburied about a week after the article above appeared. Researchers and elders tried to work out some compromise under which the bones would be “reburied” (presumably put in a facility below ground) while still accessible to scientists. But it failed. More:

According to the National Native Title Tribunal, the majority of Lake Mungo falls within the Paakantyi people’s land.

Paakantyi man Michael Young said Ms Ley having the final say was an example of settler colonialism.

“We have had that for 234 years and we are really over that side of it,” he said.

“We want our people re-established in those areas so they can determine what is best for their country and their people.”

I am not moved by the “settler-colonialism” argument. No living indigenous people know whether these remains are ancestral. The people represented by known Mungo fossils might not have reproduced, or might have left no living descendants if they did.  Their relationship to living First Nations people is unknown, and it’s a loss to science to cater to these unevidenced claims. Sure, there can be displays with casts and appreciation for the history of ancient humans that came to Australia, but what a loss to science to rebury some of the oldest H. sapiens remains known from out of Africa!

The article below (click to read) came out two days ago on the ABC:

Excerpt:

The discovery of Mungo Man and Mungo Lady, some of the most significant remains ever found in Australia, helped to re-write the history of this country and its First Peoples.

But how they, and the 106 other remains found with them, should be laid to rest has led to decades of division, secret burials and two federal court cases.

The reburial of the final skeletal remains into undisturbed and unmarked grave sites — overseen by a group of elders — is currently underway.

But some traditional owners hope a last-ditch federal court case will stop the reburials and allow a public “keeping place” to preserve the remains for further scientific study.

. . . Mungo Man is the oldest skeleton ever found in Australia at approximately 42 thousand years old — older than the pyramids in Egypt — and some of the earliest human remains discovered anywhere in the world.

This finding confirmed how long First Nations people have lived on this continent and revealed new details about how they lived at the time.

Over the 1960s and 1970s, 106 other Indigenous skeletons were removed from the same region and taken to Canberra.

The information gathered at the site led to the region being listed on the World Heritage Register in 1981, one of the first in Australia.

But the removal of the bones without their consent angered traditional owners of the three groups in the area, the Mutthi Mutthi, Paakantji (Barkindji) and Ngiyampaa people.

This sounds like a good compromise, and even some tribal elders agree with that suggestion:

Wamba Wamba and Mutthi Mutthi man Jason Kelly and other community members have long believed the remains should go to a ‘keeping place’ that would remain accessible to both scientists and descendants, as was requested by his elders.

But even the elders don’t have authority here!

But members of the Willandra Lakes Region Aboriginal Advisory Group (AAG), an advisory group of community-elected representatives of the three traditional owner groups, want the remains reburied in a secret location with a traditional ceremony so they could finally be at peace.

“A keeping place is no good for our ancestors,” Barkindji man and AAG member Ivan Johnson told ABC Mildura.

“Our ancestors were buried in the ground, and we should put them back in the ground and leave them there to rest.”

Rest? Being at peace at last? They aren’t resting, they are DEAD and only their bones remain, bones that can give us clues to human migration and evolution. What about the Garnpung Giant? Could it possibly be a specimen of Homo erectus (thought to have gone extinct about 110,000 years ago)? We won’t know.

And of course the scientists object, though there are some who have been cowed by the Authority of the Sacred Victims. Read the article to learn more. .

As the reburials proceed, so too does a federal court application brought by Jason Kelly seeking to force Environment Minister Tanya Plibersek to bring them to a halt.

He also wants the locations of the burial sites to be recorded and have burial mounds erected so descendants and the public can pay their respects.

A decision is expected to be handed down within the next week.

You can sign a petition about it having the fossils accessible in a “keeping place” here (though it won’t do much good, I suspect). Not many people have signed the petition (just over a thousand); imagine if every subscriber here signed it!  I find it unconscionable that false legands and dubious claims about ancestry impede science in this way. A “keeping place” can both respect the wishes of the indigenous people and at the same time allow scientists to study the remains.

Here’s a video from The Australian in which the anthropologist who apparently discovered Mungo Man and Mungo Lady argues for a keeping place that will allow study of the fossils.  He notes that in 20 years there will surely be new methods for studying fossils like this, making their preservation especially important.

h/t: Cate, Al

Evolution of a human artery in modern times?

January 20, 2025 • 11:20 am

This article, published in the Journal of Anatomy four years ago, was also highlighted in ScienceAlert this January 18, which is how Matthew Cobb found it.  And although the results aren’t new, I find them interesting from an evolutionary point of view and sure didn’t know about them before. (I’m not sure why ScienceAlert chose to highlight them this week.)

The paper (and the shorter popular summary) describes an Australian study of a variable trait: an extra artery in the forearm and hands of humans called “the median artery”.  It is present in fetuses, where it feeds the growing arm and hand, but regresses during development so that it’s not usually present in newborns. However, in a substantial number of cases—now about 30%—it remains as a functioning artery in adults.  The paper describes a present study of the incidence of this “vestigial artery” in modern adult Australians, and compares this incidence with that seen in adults going back to the late 19th century. There has been a marked increase in persistence—threefold!—over that period.  What we don’t know is why this is happening.  It could be strong natural selection, an environmental change we don’t understand, or both.

You can see the paper by clicking on the title below, or download a pdf here.

First, here’s what the artery looks like in an adult (caption from the paper). I’ve put a red oval around the artery:

Median artery and superficial palmar arch (anterior dissection of the left lower forearm, wrist and hand) – Median artery accompanied the median nerve and completed the superficial palmar arch laterally.

Now although the artery feeds the arm and hand, we don’t know whether it actually benefits those who have it.  The authors and ScienceAlert appear to favor natural selection as the reason for the increase over time, but we don’t know that. To know for sure, we’d have to do long-term studies of the reproductive output of individuals having the artery versus those lacking it, or perhaps genetic studies (see below). We don’t have that data and therefore cannot say anything about natural selection.

Further, perhaps its increased persistence into adulthood is due to some environmental effect. We have no data on that, either. All we can say, and we can’t even say that with a high degree of confidence, is that the percentage of adults having the artery seems to have increased drastically over time.

But I’m getting ahead of myself. The authors dissected 78 arms of Australians aged from 51 to 101 years who died between 2015 and 2016, determining how many of them had the persisting median artery.  Individuals were excluded who might have skewed the studies, including individuals with only the hands and not arms examined, people who had carpal tunnel syndrome (possibly caused by persistence of the artery), and examinations using angiography, which has a greater ability to detect arteries.  Exactly a third of adults (33.3%) showed the artery.

The authors then went back and scoured the literature, using data on adults from 47 published papers going back to 1897. Using data from that arms in individuals who died at a known age, we have a dataset of individuals born from about 1846 to 1997—a span of roughly 150 years, or about 5 human generations.  That’s a remarkably short span of time from an evolutionary viewpoint.

Nevertheless, they found a significant increase over this period of the proportion of individuals having a median artery nearly tripled—from about 10% to 30%. Here’s the most relevant graph plotting the percentage of individuals showing the artery as adults born between 1880 and 2000. (There’s considerable scatter because sample sizes at each date are small.). The authors gives a probability of less than 0.0001 that this temporal trend would be due to chance, so it’s highly statistically significant (they don’t specify whether they’re testing the regression coefficient or the correlation coefficient, but it doesn’t really matter with p values that low.

They also extrapolate this trend and say that one “could predict that the median artery will be present in 100% of individuals born in the year 2100 or later.”  It will then no longer be a persisting fetal trait, but a trait that persists throughout life, and the persisting adult trait could no longer be seen as “vestigial”, like persisting wisdom teeth in some people.

The authors do suggest that environmental factors could play a role in this increase, but also that it could be due to natural selection. Such selection, to cause such a strong change in just a few generations, would have to be strong! The ScienceAlert article plays up the selection part, saying this:

“This increase could have resulted from mutations of genes involved in median artery development or health problems in mothers during pregnancy, or both actually,” said Lucas.

We might imagine having a persistent median artery could give dexterous fingers or strong forearms a dependable boost of blood long after we’re born. Yet having one also puts us at a greater risk of carpal tunnel syndrome, an uncomfortable condition that makes us less able to use our hands.

Nailing down the kinds of factors that play a major role in the processes selecting for a persistent median artery will require a lot more sleuthing.

Indeed, a TON of more sleuthing. What would be required to show selection would be either or both of two things:

1.) Show that, over a long period of time, individuals with median arteries as adults leave more offspring than individuals lacking these arteries. This is how the Framingham Heart Study, which began in 1948, showed that there appeared to be natural selection in women for reduced height, increased stoutness, reduced total cholesterol levels, and lower systolic blood pressure. Further, there appears to have been selection for women to produce their first child earlier and to reach menopause later. This is what I tell people who ask me, as they inevitably do when I lecture on human evolution, where our spercies is going. Not that exciting, is it? But of course the time span of such studies are necessarily limited.

2.) Find the genes responsible for the persistence of the artery and show, by population-genetic analysis, that those genes leading to persistence have been undergoing positive selection. This would be even harder because we have no idea what those genes are.

Absent those two types of studies, all we can say is that we have a putative case of evolution occurring over a short period of human evolution.

Caveats: The authors offer these caveats, and I have one more:

Limitations of the present study include the fact that the number of whole cadavers that were available for the study was not adequate. In addition, our search of the literature may have missed some publications not listed in Google Scholar. Finally, the definitions of ‘persistent median artery’ may have differed somewhat among the various published studies included in the present study.

Finally, as far as I can determine from looking at a few of the papers they cite in the older literature, the samples of arms came not just from Australia, but from other countries like Brazil and South Africa. Given that we know that at present populations from different places differ in the persistence of the artery, this could also throw some bias into the data. However, to create a time course this significant, I don’t think that using arms from different places could be the explanation, for it would require that arms from older people tended to come from places which had a lower incidence of the artery in general.

h/t: Matthew Cobb