Consensus in archaeology has posited that mechanically propelled weapons, such as bow-and-arrow or spear-thrower-and-dart combinations, appeared abruptly in the Eurasian record with the arrival of anatomically and behaviorally modern humans and the Upper Paleolithic (UP) after 45,000 to 42,000 years (ka) ago, while evidence for weapon use during the preceding Middle Paleolithic (MP) in Eurasia remains sparse. The ballistic features of MP points suggest that they were used on hand-cast spears, whereas UP lithic weapons are focused on microlithic technologies commonly interpreted as mechanically propelled projectiles, a crucial innovation distinguishing UP societies from preceding ones. Here, we present the earliest evidence for mechanically propelled projectile technology in Eurasia from Layer E of Grotte Mandrin 54 ka ago in Mediterranean France, demonstrated via use-wear and impact damage analyses. These technologies, associated with the oldest modern human remains currently known from Europe, represent the technical background of these populations during their first incursion into the continent.
One of the questions is whether this could be Neanderthals. I think at this point there is a fair amount of genetic evidence for Neanderthal-modern contact well before the Upper Paleolithic expansion associated with non-African ancestry today. The Altai Neanderthal seems to have “modern-like” ancestry and Neanderthals have modern/African-like Y and mtDNA.
Could Neanderthals do bows and arrows? No idea. But this could clearly be modern humans, who seem to have pushed into Neanderthal territory several times. Did Neanderthals ever move into Africa? Who knows?
I do wonder though about William Calvin’s ideas that human brain development was triggered by throwing things. Perhaps Neanderthals didn’t have the locomatory abilities in this domain? Who knows.
This dated sedimentary and taphonomic framework for the Ngan-dong bone bed does not support an overlap between modern humans and H. erectus in this region…Instead, the Ngandong fauna in facies A (140 ±24ka) pre-dates the rainforest-associated site of Punung (between 128 ±15ka and 118 ±3ka)…which agrees with the proposed biostratigraphical sequence of Java based on the palaeoenvironmental and associated faunal changes
Paleoanthropologists that I follow on Twitter seem to find the dating creditable. I can’t evaluate it personally, so I’ll take that as a given.
From what I can see the authors seem to be presenting a hypothesis where environmental shocks and decline led to the local extinction of the “erectus” lineages before the arrival of modern humans, perhaps 60 to 80 thousand years ago (depending on which archaeological dates you accept). It does seem likely though that Denisovans were still present when modern humans arrived, going by the latest genetic evidence, while best dating of the “hobbits” of Flores suggests they went extinct only 60,000 years ago.
First, I would bet that various hominin groups were around after their last presence in the archaeological record. I now think there’s enough circumstantial evidence to suggest “modern” African-related/derived humans were present in and around southern and eastern Asia around ~100,000 years ago. There is evidence of modern humans in Sumatra ~70,000 years ago. Also, there are signs of gene flow from modern humans into Neanderthals hundreds of thousands of years ago.
Flores, various Denisovans, early modern humans, and also now the hominins in the Philippines, point to a high degree of speciosity in Southeast Asia. This is not terribly surprising. Southeast Asia is a relatively “protected” area of Eurasia, and so can serve as a refuge during inclement periods. And, during the Pleistocene, its surface was much more extensive. Sundaland covered the western third of modern Indonesia. Many of the prime habits are almost certainly underwater today.
To step back, we also have to note that it seems the overwhelming proportion of ancestry in modern humans outside of Africa dates to an expansion from a very small group that began 50-60,000 years ago. We have some evidence, obviously, of uptake of Neanderthal and Denisovan ancestry. But no strong evidence of “first wave” modern human ancestry. I think part of this is simply the reality that if there was mixture at low levels with earlier groups of modern humans in places like Southeast Asia one may not have the power to detect it well because the two lineages are not particularly distinct, as is the case with Neanderthals/Denisovans vs. modern humans.
I put “erectus” in quotations because what do we even mean by this? Was “erectus” really a coherent species for a million years in Southeast Asia? I doubt it. It’s more of a catchall and placeholder from what I can tell. Before the expansion of 50-60,000 years ago, the Eurasian landscape was much more diverse in terms of humans. Neanderthals seem to be relatively homogeneous, but Denisovans not so much, and I think the same would apply to various “erectus” groups. I bet that once some ancient DNA comes back from China we’ll see more than just Denisovans ~100,000 years ago.
I want to elaborate on my earlier post, Deep Denisovan Population Structure. Though I don’t put much stock in any particular result, including the most recent ones reported at a conference, I think that biogeography tells us a lot about what we should expect in the future.
First, notice that Neanderthals, Denisovans, and European hunter-gatherers have all exhibited evidence of being subject to massive bottlenecks and very low effective population sizes. Things changed in Europe with the arrival of Neolithic farmers, whose higher genetic diversity is in the range of modern people. I think this is indicative of the fact that abiotic factors, climatic shocks, drove down population sizes periodically consistently with all these northern hominins. I’m not saying that population sizes couldn’t get large periodically, but the fact that later Altai Neanderthals are genetically closer to Neanderthals from Croatia than earlier Altai Neanderthals indicate lots of local population extinction. It applied to Neanderthals, it applied to northern Denisovans, and, it applied to northern modern humans. Only with a change in the mode of production were higher long-term population sizes feasible.
On this week’s episode of The Insight (Stitcher and Google Play) we talk to Lee Berger, author of Almost Human and a paleoanthropological revolutionary. Or, less sensationally Lee tells us his view on the practice and results of science in his field (which is literally in the field).
Like most scientists, Lee is passionate about his work, but unlike many, he’s really good at talking about it. That’s an important skill going forward because science is usually funded by the public or private foundations.
Here is the original paper on Homo naledi, Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. This small hominin had a brain 30% the size of our own, and lived until at least (and likely later than) 200,000 years ago in southern Africa. At some point they’ll get DNA out of naledi. Lee’s current opinion based on morphology seems to be that this is a highly basal lineage. That is, it separated from the one group that led to anatomically modern humans 2 million years ago!
Also, if you haven’t, please give us 5 stars on iTunes/Stitcher! I know how many readers I have, and 59 ratings aren’t the limit of reach of my audience.
Dienekes Pontikos resurfaces with a post, Out of Africa: a theory in crisis. The title is a bit hyperbolic. But in Dienekes’ defense, he’s been on this wagon for over ten years, and the evidence is moving in his direction, not against him. I think a little crowing is understandable on this part.
With that being said, I think the biggest rethinking that we’re doing is less about where modern humans arose (Sub-Saharan Africa, North Africa, the Middle East), but how they arose. Some geneticists are quite open to the idea of Eurasian (Neanderthal?) back-migration to Africa several times (and out of Africa several times). Others are positing that a “multiregional” model might actually be about the situation within Africa.
A simple stylized model of a rapid punctuated expansion of humanity which replaces other lineages in toto is no longer likely. There has been widespread admixture, even though the last major demographic wave seems to be overwhelmingly predominant, at least outside of Africa. But the whole process might result in a much more complex history than we had thought.
The multiregional model is probably wrong on the details. The history of our species is not really phyletic gradualism and anagenesis. But there are also many processes and dynamics which a multiregional model takes into account and anticipates that probably are important in a general sense toward understanding the origin of our species.
Current Anthropology has a bunch of articles related to the human settlement of Asia in its latest issue ahead of print. Aside from Martin Sikora’s most of them have a more traditional paleontological focus, so it’s pretty tough for me to understand them in context. But it’s all important to take in as we get a better and better understanding of the process.
All the articles are open access, so there’s no excuse not to read them!
The cool thing about the first paper is that it combined UK Biobank data, 100,000+ individuals, with hundreds of thousands of markers, and Neanderthal genomic data. Note that: a paper comparing ancient genomes with over 100,000 individuals and hundreds of thousands of markers. Now that’s 2017!
To find archaic alleles they:
Looked for variants fixed in Yoruba (no Neanderthal), and homozygote or heterozygote in the alternative state in the Altai Neanderthal, which also segregated (varied) in the UK Biobank population. Basically, an allele not found in Africans but found in Neanderthals, and also found in appreciable fractions in the UK Biobank data set.
They then took the SNPs above, and only retained ones confidently embedded in tracts of Neanderthal ancestry. Haplotype was consistent with admixture ~50,000 years ago (the length), and exhibited lower distance to Neanderthal than African genomes.
They did some stuff with tag-SNPs though. Overall they found a lot of the usual suspects. Pigmentation. Chronotype. But this passage jumped out at me:
In fact, for most associations, Neanderthal variants do not seem to contribute more than non-archaic variants. However, there are four phenotypes, all behavioral, to which Neanderthal alleles contribute more phenotypic variation than non-archaic alleles: chronotype, loneliness or isolation, frequency of unenthusiasm or disinterest in the last 2 weeks, and smoking status.
What they are saying is that for a lot of traits Neanderthals don’t really change the direction of the trait in humans, they just add more variants. This seems to be the case in pigmentation. Entirely unsurprising, Neanderthals were around for hundreds of thousands of years. Of course they had a lot of variation amongst themselves.
But the behavioral traits above shifted the modern humans in the aggregate who had the archaic allele somewhat. That is, being Neanderthal derived made a difference.
There have long been speculations about the sociality (or lack thereof) of Neanderthals. It would not be surprising if small population sizes meant that Neanderthals were less gregarious than modern humans, and that their lack of gregariousness did not redound to their benefit when they encountered the last wave of moderns.
Which brings us to the second paper. The big deal here is that it gives us a very high quality ancient genome of a European Neanderthal that lived ~50,000 years ago (the Vindija sample). Before this we had a high quality ancient genome of an Asian Neanderthal that lived ~125,000 years ago (Altai sample). ~75,000 years is a long time. It’s so long that almost all the ancestry of modern non-Africans would have converged to a common population that long ago. Additionally, all the available data indicate that most of the admixture into modern humans from Neanderthals occurred around 50,000 years ago. So this new sample is definitely welcome.
It is not surprising that the Vindijia sample seems to be closer to the Neanderthal admixture population than the Altai sample. First, it is likely geographically closer, since all non-African populations have some Neanderthal ancestry West Asia is probably the top candidate, and southeastern Europe is not that far from West Asia in comparison to Mongolia. Second, it is basically contemporaneous with the Neanderthals who contributed ancestry to modern humans who left Africa. This means that the Neanderthal admixture percentage in non-Africans goes up moderately.
To me this is the most important paragraph:
It has been suggested that Denisovans received gene flow from a human lineage that diverged prior to the common ancestor of modern humans, Neandertals and Denisovans (2). In addition, it has been suggested that the ancestors of the Altai Neandertal received gene flow from early modern humans that may not have affected the ancestors of European Neandertals (13). In agreement with these studies, we find that the Denisovan genome carries fewer derived alleles that are fixed in Africans, and thus tend to be older, than the Altai Neandertal genome while the Altai genome carries more derived alleles that are of lower frequency in Africa, and thus younger, than the Denisovan genome (20). However, the Vindija and Altai genomes do not differ significantly in the sharing of derived alleles with Africans indicating that they may not differ with respect to their putative interactions with early modern humans (Fig. 3A & B). Thus, in contrast to earlier analyses of chromosome 21 data for the European Neandertals (13), analyses of the full genomes suggest that the putative early modern human gene flow into Neandertals occurred prior to the divergence of the populations ancestral to the Vindija and Altai Neandertals ~130-145 thousand years ago (Fig. 2). Coalescent simulations show that a model with only gene flow from a deeply diverged hominin into Denisovan ancestors explains the data better than one with only gene flow from early modern humans into Neandertal ancestors, but that a model involving both gene flows explains the data even better. It is likely that gene flow occurred between many or even most hominin groups in the late Pleistocene and that more such events will be detected as more ancient genomes of high quality become available.
These results seem to support earlier work indicate that Denisovans were admixed with an ancient hominin group which diverged very early on (probably the descendents of East Asia erectus?). And, that Neanderthals received gene flow from a lineage of modern (African?) humans 150,000 or more years ago. Since the latest work suggests that modern humans in some form have existed between from 200,000 to 350,000 years ago, this is entirely plausible.
But, it brings us the take-home message that the emergence of Pleistocene humanity was to a some extent characterized by reticulate gene flow, rather than a bifurcating tree.
The above tweet is in response to a article which reports on the finding past month in PNAS, Early history of Neanderthals and Denisovans. It’s open access, you should read it. I don’t think I’ve reviewed it because I haven’t dug through the supplements. To be frank this is a paper where you pretty much have to read the supplements because they’re introducing a somewhat different model here than is the norm.
I talked to Alan Rogers at SMBE about this paper. Broadly, I think there might be something to it, and it’s because of what David says above. It is simply hard to imagine that Neanderthals could be extremely successful with such low genetic diversity as we see, and spread so thin. Now, the Quanta Magazine tries to emphasize that the effective population is not the true census population, but I wish it would have explained it more clearly. Basically, the size that is relevant for breeding is obviously not going to the same as a head count. And, because effective populations are highly sensitive to bottlenecks you can get really small numbers even when the extant population at any given time may be large.
The PNAS paper makes some novel inferences, and I’ll set that to the side until I read the supplements. But I don’t think it’s crazy that population structure within Neanderthals could be leading to lower total genetic diversity.
Genetic science is good at many things, but precise dates have not always been its strong suit. There are many reasons for this, and the possibility of variable mutation rates puts a major a barrier in our ability to get absolute precision. From what I can archaeology is a little better here, despite all the problems that this discipline has.
. In this first major synthesis we focus on the dating and sedimentology of Boodie Cave to establish the framework for ongoing analysis of cultural materials. We present new data on these cultural assemblages – including charcoal, faunal remains and lithics – integrated with micromorphology, sedimentary history and dating by four independent laboratories. First occupation occurs between 51.1 and 46.2 ka, overlapping with the earliest dates for occupation of Australia. Marine resources are incorporated into dietary assemblages by 42.5 ka and continue to be transported to the cave through all periods of occupation, despite fluctuating sea levels and dramatic extensions of the coastal plain.
The best current work sees to suggest that unlike most world populations Australians have not experienced much turnover. That is, the first settlers are the ancestors by and large of the current native populations. If this is correct we’re getting some really clear lower bound values for the date of Neanderthal and Denisovan admixture into our lineage.
One of the questions is whether this could be Neanderthals. I think at this point there is a fair amount of genetic evidence for Neanderthal-modern contact well before the Upper Paleolithic expansion associated with non-African ancestry today. The Altai Neanderthal seems to have “modern-like” ancestry and Neanderthals have modern/African-like Y and mtDNA.
Flores, various Denisovans, early modern humans, and also now the hominins in the 
