All Europeans of Belgian Descent?

Tech Times is reporting that all modern Europeans are descended from a population from Belgium.  James Maynard writes:

Ancient DNA left over from the last ice age shows that all Europeans, at one time, were descended from early humans living in Belgium. Analysis of genomes also suggested our distant ancestors underwent significant evolutionary changes during the Ice Age and a few thousand years following that frigid era.

A total of 51 genetic samples were examined in the latest study, a vast improvement in understanding compared with the four examples available previous to now.

The study suggests that all modern Europeans sampled could trace their ancestry back to a large population living around 37,000 years ago in what is now Belgium.

The Origins of Modern Humans, The Fossil Evidence, Part II

The second of my BioLogos posts on the fossil evidence concerning the origins of modern humans is up. 

Dennis Venema on Human Evolution and Palaeogenomics

Dennis Venema is doing the genetics end of human evolution.  He has, as with most evolutionary creationists, taken the long view of creation, to the point where he has publicly stated that the modern human genome could not possibly have originated with two individuals.  Knowing what I do of the fossil record (upcoming BioLogos posts on June 16-18), I have no problem with that.  He focuses on palaeogenomics, and writes:

The discovery of Neanderthal remains in the same location that preserved the exceptional Denisovan DNA at last provided a very high quality Neanderthal genome, the analysis of which was published just this year. This new data allowed for several more robust analyses comparing human, Denisovan, and Neanderthal genomes. These analyses produced several noteworthy results: modern mainland Asian populations also have a small amount of Denisovan DNA; humans contributed some DNA variation to Neanderthals; Neanderthals and Denisovans interbred, with DNA variation flowing both ways; and (perhaps most interestingly) Denisovans have DNA variation that suggests they interbred with yet another archaic hominin group, possibly Homo erectus.

While the palaeogenomic data indicate a split time of c. 600 Ky years for modern humans and Neandertals, it is fairly clear from other genetic evidence that there was at least some interbreeding between early moderns and Neandertals all the way up to around 50 Ky B.P. (perhaps as recently as 29 Ky, given the information from the Portuguese burial at Lagar Velho), as well as interbreeding between the newly emerging African moderns and African archaic Homo sapiens. 

The news that the Denisovans have some very archaic DNA in them is not surprising.  IF modern humans and Neandertals split around 600 Ky B.P., the only people running around on the landscape at that point were early archaic Homo sapiens/late Homo erectus.  The salient feature of the name "archaic Homo sapiens" is that it is not a taxonomic name but rather a linguistic "catch-all."  The primary reason for this is because, as I noted in my series on human origins, the earliest members of this group still have some Homo erectus characteristics, while the later ones look more modern.  When these fossils, which all date to between (possibly ) 800 and 400 Ky B.P., were pulled out of the ground, researchers did not know what to call them, so they applied this "catch-all."  Adding to the confusion is that some of the archaic Homo sapiens crania from Africa bear more than a passing similarity to some of the finds in Europe.  All were clearly transitional but what to call them was a mystery.  Researchers such as Bernard Wood, applying systematics to the problem, have suggested that these forms should be given the name Homo heidelbergensis.  Such a taxon would, however, have quite a lengthy geomorphochronocline, stretching its limits, perhaps, to the breaking point. For a refresher on these fossils, you might want to read this post. 

So, if the split between modern humans and Neandertals was around 600 Ky B.P., who would have been the progenitors of these groups?  Modern humans don't appear on the landscape until between 160 and 190Ky B.P.  Neandertals don't appear until maybe 300 Ky B.P.  Here is one possible scenario. Sometime prior to 600k B.P., there was a migration out of Africa by one or more groups of archaic Homo sapiens/late Homo erectus.  This explains the similarities between the Petralona and African Kabwe crania, as well as that of the Gran Dolina remains and the African Bodo cranium.  In Africa, the archaics went about their business being archaic until around 200 ky B.P., when the modern genome began to arise (in response to what?).  In Europe, over time, in the face of not one but two ice ages (The Riss and Würm), one group evolved into the Neandertals, who's remains are found in Europe, the Levant, northern Iraq and very western Russia. Populations in the two areas would have, depending on the level of gene flow in the circum-Mediterranean area, become genetically isolated.

Now here is the really odd thing.  When these groups reunited, so to speak, they discovered that, not only was there an attraction, they were still genetically compatible after some 500 thousand years apart—to a point. Even though they actually produced viable offspring (and the presence of Neandertal genes in modern humans demonstrates that they were), because the Neandertal and modern human genomes were "optimized" if you will, eventually over time, hybrid depression would likely have ensued, reducing the fitness of the hybrid offspring.  This may account for the ultimate demise of the Neandertals, who had a genome that, with the warming at the end of the early Würm stadial, was likely undergoing negative selection pressure.  If, in fact, there was a swamping of the Neandertal genome by arriving moderns through the gates of Europe, this would have sped up the process.

This scenario is bare bones at best but explains much of the fossil data.  It leaves aside the hotly contested notion of whether or not Neandertals were a separate species from the early moderns and, with them, reflected a syngameon, or whether, as Milford Wolpoff contends, they reflect a widely polytypic species that interbred at the peripheries.  That is for another day. 

Archaeological Evidence: Neandertals and Modern Humans Interacted and Interbred

The Newsroom at the University of Colorado has released news of a study that links the archaeological evidence in Europe with Neandertal/early modern human interaction and, probably, interbreeding. They write:

Anthropologists using computer modeling to determine how early hominins adapted to climate change during the last Ice Age, have gained new insights into why Neanderthals disappeared as a distinct population some 30,000 years ago.

The scientists believe Neanderthals interbred with more numerous modern humans until they ceased to exist as their own population.

This is called "gene swamping" and is not uncommon. The authors further argue:

“Neanderthal genes make up between one and four percent of today’s human genome, especially in those of European descent. Their legacy lives on in our genome and possibly in our cultural knowledge.”

Modern humans begin to show up in Europe during the Early Würm/Late Würm glaciation, between 35 and 40 thousand years B.P. A good representation of these hominins are those from the cave of Mladeč, which, while being classified as modern humans, have characteristics reminiscent of Neandertals. Even the later hominins such as those from the central European site of Dolní Vĕstonice, show archaic characteristics such as expanded occipital buns (a bulge at the rear of the vault). This all makes sense within the context of hybridization between the two groups of people. Fred Smith was right.

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Modern Humans Out of Africa Earlier Than Thought?

The Australian is reporting on the find in Arabia of stone tools purported to be crafted to modern humans that date to around 100 000 years ago (date derived by thermoluminescence). They write:

Jeffrey Rose, an archaeologist with Britain's Birmingham University and head of the Dhofar Archaeological Project, said: "After a decade of searching in southern Arabia for some clue that might help us understand early human expansion, at long last we've found the smoking gun of their exit from Africa."

The discovery also challenges current thinking about the route the migrants took, say Dr Rose and his colleagues, including geochronologist Bert Roberts of Wollongong University.

The article shows up in PLoS¹. This is intriguing and certainly adds one more piece of the puzzle but I am not sure why it so earth-shattering. We already know that we have hominins in the Levant that pass, in most ways, for modern humans and are dated to between 90 and 110 000 B.P. We also have the Herto remains at 140-160 000, which are also mostly modern. A glance at the map shows that the gap between the Horn of Africa and the Arabian peninsula is very narrow here and it would not have been a problem to navigate the waters at this point. This just represents another migration route of many. The authors of the paper call the assemblage that was discovered a Nubian variant of the “Middle Stone Age,” which tracks as a post-Acheulean industry and is present in various forms in Africa from about 300 000 years B.P. down to around 40 000 or so. Here is the map from the article:



As you can see, there is Nubian in both Arabia and in the Nile valley. Interestingly, when you get to the Levantine peninsula, you run into “modern” humans creating Levantine Mousterian, another Middle Palaeolithic industry, which means they had contact with the Neandertals who were escaping the cold to come south during the early Würm glaciation. It is during the Early Würm/Late Würm interglacial period that the early moderns get the bright idea to head north, out of the Levant.

¹Rose JI, Usik VI, Marks AE, Hilbert YH, Galletti CS, et al. (2011) The Nubian Complex of Dhofar, Oman: An African Middle Stone Age Industry in Southern Arabia. PLoS ONE 6(11): e28239. doi:http://dx.doi.org/10.1371/journal.pone.0028239


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The Evolution of Modern Clothing

A University of Florida study has determined that modern humans first developed clothing around 170,000 years ago and that this enabled them to migrate out of Africa. Danielle Torrent writes:

Principal investigator David Reed, associate curator of mammals at the Florida Museum of Natural History on the UF campus, studies lice in modern humans to better understand human evolution and migration patterns. His latest five-year study used DNA sequencing to calculate when clothing lice first began to diverge genetically from human head lice.

Funded by the National Science Foundation, the study is available online and appears in this month’s print edition of Molecular Biology and Evolution.

“We wanted to find another method for pinpointing when humans might have first started wearing clothing,” Reed said. “Because they are so well adapted to clothing, we know that body lice or clothing lice almost certainly didn’t exist until clothing came about in humans.”

The data shows modern humans started wearing clothes about 70,000 years before migrating into colder climates and higher latitudes, which began about 100,000 years ago. This date would be virtually impossible to determine using archaeological data because early clothing would not survive in archaeological sites.

Oh? Okay, lets parse this. Modern humans invented clothing so they could move into colder climates. News flash: hominids were knocking on the gates of Europe 1.8 million years ago. This we know from the Caucasus site of Dmanisi. Furthermore, there are Chinese Homo erectus sites that date to between 250 and 550 thousand years ago. These locales were not temperate. The site of Zhoukoudian is near Beijing, which can experience temperatures as low a -4 degrees Fahrenheit. It is with this hominid that we see the first control of fire. The story continues:

“The new result from this lice study is an unexpectedly early date for clothing, much older than the earliest solid archaeological evidence, but it makes sense,” said Ian Gilligan, lecturer in the School of Archaeology and Anthropology at The Australian National University. “It means modern humans probably started wearing clothes on a regular basis to keep warm when they were first exposed to Ice Age conditions.”

Again, the hominids in China lived during the East Asian equivalent of the Mindel glaciation, during which it would have been colder than it is now.The story continues:

The study also shows humans started wearing clothes well after they lost body hair, which genetic skin-coloration research pinpoints at about 1 million years ago, meaning humans spent a considerable amount of time without body hair and without clothing, Reed said.

Not sure I buy this either. You can't survive in those locales during glacial periods without one or the other. You can't pick fire up and move it around with you. During the mid- to late Pleistocene, you had hominids in southern Europe, northern China, the Caucasus and other places. During the Würm glaciation, the tundra line was at Vienna.

I would like to see a follow-up story.

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Neandertals "Doomed" to Extinction?

Yes, according to Clive Finlayson, an ecologist. In a story in Sindhtoday, the argument is put forth that:

Finlayson argues that it was a deadly combination of bad luck and climate change that caused the demise of the Neanderthals.

They were a species caught in the wrong place at the wrong time in a rapidly changing world, he said. “By the time the classic Neanderthals had emerged, they were already a people doomed to extinction,” he said.

A series of ice ages ate away the forest habitats where Neanderthals and their predecessors, Homo heidelbergensis, made a living sneaking up on big game. As their numbers declined, those who remained took refuge in warmer parts of Europe, nearer the Mediterranean. But, a final drop in temperatures that began around 50,000 years ago made even this meager living unsustainable.

Here's the problem that I have with this interpretation: Neandertals appear in the fossil record around 100-150 ky BP and are even found in Southwest Asia around 125 Ky BP (Zuttiyeh). The early Würm glaciation begins around 110 Ky BP and goes roughly up until 34-37 Ky BP. Are we really to believe that for some 70 thousand years, Neandertals adapted to the landscape just fine and then, suddenly, couldn't cut the mustard? It is much more likely that their disappearance had something to do with the arrival of modern humans around 35-40 ky BP. The Aurignacian first appears in the Balkans, at Bacho Kiro Cave around 43 ky and, whether one wants to go the admixture route, the assimilation route or the replacement route, there was clearly contact there and it clearly had an effect on the local Neandertal populations. Maybe he writes about this in the forthcoming (assumedly) paper but nothing of that is clear from this story.

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Neandertal Fossil Found in the North Sea

A skull fragment that was retrieved from the North Sea is believed to that of a Neandertal adult male. The story, from UPI continues:

The 60,000-year-old Neanderthal is the first confirmed specimen to be found undersea anywhere in the world, the BBC reported Monday. The fossil was found by Luc Anthonis, a private collector from Belgium, among animal remains and stone artifacts recovered several miles off the coast of the Netherlands in 2001.

Well, this certainly confirms traffic between the British Isles and the mainland, which we pretty much knew was going on anyway, based on previous remains in England.