On the Heels of the Discovery of Homo luzonensis...

A new study from the journal Cell suggests that there were multiple migrations of individuals into Southeast Asia with the Denisovan genome.  Here is the summary from Cell.

Genome sequences are known for two archaic hominins—Neanderthals and Denisovans—which interbred with anatomically modern humans as they dispersed out of Africa. We identified high-confidence archaic haplotypes in 161 new genomes spanning 14 island groups in Island Southeast Asia and New Guinea and found large stretches of DNA that are inconsistent with a single introgressing Denisovan origin. Instead, modern Papuans carry hundreds of gene variants from two deeply divergent Denisovan lineages that separated over 350 thousand years ago. Spatial and temporal structure among these lineages suggest that introgression from one of these Denisovan groups predominantly took place east of the Wallace line and continued until near the end of the Pleistocene. A third Denisovan lineage occurs in modern East Asians. This regional mosaic suggests considerable complexity in archaic contact, with modern humans interbreeding with multiple Denisovan groups that were geographically isolated from each other over deep evolutionary time.

These data, in combination with the new Luzon material further suggest that the population interrelationships in Southeast Asia were complex, with considerable mixing between Denisovans, archaic Homo sapiens, eastward-migrating Neandertals and who knows how many other groups. We know from the material in China that the fossil material of even 100 thousand years back exhibits multiple origins.  As I noted about the Xuchang hominins at the time:

These two Chinese skulls stand at the crossroads of these population movements. While showing clear Neandertal characteristics, they also express modern traits, possibly reflecting mixing with the late, modern human arrivals represented by the recent modern human finds at Daoxian. Yet they also express a clear link to ancient East Asian populations. The implications of these skulls are stark: there has been widespread population mixing and regional continuity in Europe and Asia for at least 400 thousand years. Not only did the Neandertals feel enough cultural kinship to mate and have children with these East Asian people, the early modern humans coming out of Africa did, as well. As Chris Davis of China Daily News put it: “One big happy family.”

The presence of the hominins in Luzon, as well as the new research reported here suggests that this complexity comprised all of East Asia.

More Evidence of Complex Tool Creation By Archaic Homo sapiens

New excavations at Boxgrove, a site which dates from approximately 300 thousand years ago has yielded tools that show more complex creation strategies.  From the Independent:

The specific stone tools which were analysed as part of the study were sophisticated flint hand axes, which had required a special technique to shape them.

The technique is known to prehistorians as ‘platform preparation’. In most very early stone tools, the manufacturing process is a simple single-stage affair in which the toolmaker merely hits a lump of flint with a stone repeatedly to systematically knock bits off it until the lump has been reduced to a desired shape.

However, more sophisticated toolmakers employed a two-stage approach. First they would successively "soften up" small portions of the flint’s surface, so as to then be able to more accurately remove flakes from it, thus creating a much more sophisticated and effective tool with a better and more refined cutting edge.

Quite a bit of evidence is emerging that the group of hominins loosely called “archaic Homo sapiens” was considerably more technologically and socially advanced than we once thought. Whether or not they looked modern, they were beginning to act that way. 

Indian Site of Attirampakkam Pushes Middle Palaeolithic of India Back to 385 Kya

Great Googlymoogly!  Fresh on the heels of the discovery of the Misliya site (upcoming BioLogos post) that the Middle Palaeolithic Levallois technology was present in Israel as early as 194 thousand years ago, we now have news from India that places the emergence of the same technology as early as 385 thousand years ago.  From Malcolm Ritter at the site PhysOrg:

Homo sapiens arose in Africa at least 300,000 years ago and left to colonize the globe. Scientists think there were several dispersals from Africa, not all equally successful. Last week's report of a human jaw showed some members of our species had reached Israel by 177,000 to 194,000 years ago.

Now comes a discovery in India of stone tools, showing a style that has been associated elsewhere with our species. They were fashioned from 385,000 years ago to 172,000 years ago, showing evidence of continuity and development over that time. That starting point is a lot earlier than scientists generally think Homo sapiens left Africa.

This tool style has also been attributed to Neanderthals and possibly other species. So it's impossible to say whether the tools were made by Homo sapiens or some evolutionary cousin, say researchers who reported the finding Wednesday in the journal Nature.

Nowhere is there any indication that modern humans are associated with the tools at Attirampakkam (ATM). In fact, there are no hominin remains whatsoever at ATM. The Indian subcontinent has always had a paucity of human remains, the most notable of which is the Narmada Homo erectus cranium.  In Europe, the Levallois technology, which also shows up at ATM, is almost exclusively associated with Neandertals and in the Levant, at the Skhul, Qafzeh, Tabun and Amud sites in the Mt. Carmel region, it is used by both Neandertals and early moderns. Consequently, while someone was using early Middle Palaeolithic tools at ATM, we don't know who.

What is incredibly striking about the ATM site is that, from 385 ky down to 172 ky, there is continuous technological evolution, beginning with what the describers call the “terminal Acheulean,” through a punch flake industry with points, to knives.  Another point made by the authors is that this Middle Palaeolithic industry appears and flourishes during a time where other sites in India are still using Acheulean technology.  This suggests “that spatial variability among Palaeolithic cultural sequences is larger than previously thought.”  From the Nature article¹:

The behavioural transformations that mark the advent of the Indian Middle Palaeolithic at ATM are summarized by the following diagnostic features: the obsolescence of Acheulian large-flake reduction sequences, with a directional shift towards smaller tool components; the adoption and continuance of Levallois recurrent and preferential strategies; a gradual intensification of blade reduction; and an increased use of finer grained quartzite during phase II than during A gradual discontinuation of biface use—which becomes definite at ATM after approximately 172 ± 41 ka—has been reported at other Middle Palaeolithic and Middle Stone Age sites worldwide (see Supplementary Information and references therein).

This is an astounding find for so many reasons. It establishes the appearance of the Levallois technology, one we know originated in Africa, outside Africa over 150 thousand years earlier than we thought. This is a technology that was considered to have originated some 400 thousand years ago. We may now have to revise this date further into the past.

It shows a clear progression of human cultural evolution, from the late Acheulean hand axes, through Middle Palaeolithic Levallois technology to a more blade-oriented technology.  Sadly, it appears as though the site began to fall into disuse and the sequence stops cold around 74 kya.  This is not surprising since it coincides with the Toba supervolcano eruption in Indonesia.  Nonetheless, as the authors point out, it suggests multiple migrations out of Africa of first archaic Homo sapiens, then modern Homo sapiens, such as those in Misliya and that these groups interacted with the Archaic hominins they encountered along the way.

¹Akhilesh, K., Pappu, S., Rajapara, H. M., Gunnell, Y., Shukla, A. D., & Singhvi, A. K. (2018). Early Middle Palaeolithic culture in India around 385–172 ka reframes Out of Africa models. Nature, 554, 97. https://doi.org/10.1038/nature25444

Genetic Data Indicates Another Migration of Archaic Homo sapiens Out of Africa

Ars Technica is running a story based off of a Nature Communications article about a migration of archaic Homo sapiens out of Africa that took place more recently than the one at c. 650 kya that was hypothesized to have given rise to the Neandertals. Cathleen O'Grady writes:

The picture painted by nuclear DNA (nDNA) is that, between 765,000 and 550,000 years ago, our ancestors in Africa diverged into two groups. One group would eventually lead to our own species, although we wouldn't make an appearance until around 200,000 years ago. The other group would lead to Neanderthals and the closely related Denisovans. This proto-Neanderthal/Denisovan group left Africa for Eurasia at some point; sometime around 430,000 years ago, they diverged into distinct Neanderthals and Denisovans.

But the picture painted by mtDNA is different. Neanderthal mtDNA is more similar to modern humans than it is to Denisovan mtDNA. And the divergence date between us and them, when estimated based on mtDNA, is much more recent—between 498,000 and 295,000 years ago.

Some researchers have suggested that you can explain this mixed genetic evidence if Neanderthals interbred with another, more recent African group of humans. This would provide them with different mtDNA after they split from Denisovans. And that, in turn, means that there must have been humans, closely related to our own species, who left Africa for Europe far earlier than previously suspected.

It is not such a stretch to suggest that the recent finds from Jebel Irhoud may be a population related to this mystery population.  The Jebel Irhoud crania show modern characteristics in the face and have been placed in the modern Homo sapiens clade (if provisionally).  Whether or not they have enough traits found in later humans to be the stem group of anatomically modern Homo sapiens is not currently known.  Jebel Irhoud is a hop, skip and a jump to Gibraltar, which we know had already provided an avenue of migration for earlier populations of early Homo which gave rise to Homo heidelbergensis in Europe.

As the story notes, there are remarkable similarities in stone tool technologies between the northern  African Middle Stone Age and the European late Acheulean and early Mousterian tools.  There are Levallois flakes found in both areas, as well as similarly-made knives and points.  This suggests that populations in North Africa had some contact with those of southern Europe.  As we push the age of the modern human clade back in time, these discoveries help to frame the appearance of modern humans and how they interacted with the populations around them.  Exciting times!

The Nature Communications article, Deeply divergent archaic mitochondrial genome provides lower time boundary for African gene flow into Neanderthals can be found here and was free when I read it.

Another Human Species in China?

The Christian Science Monitor and other outlets are reporting on a new find from Xuchang, China, that seems to possess intermediate traits between archaic and modern Homo sapiens:

In an article published Friday in the journal Science, the researchers note that the skull fragments date to the Late Pleistocene epoch, a time marked by the expansion of H. sapiens and the extinction of other species in the genus Homo. During the early part of that epoch, Neanderthals roamed Europe and western Asia while humans began to journey out of Africa. But fossil records of human species in Eastern Asia from that time period are thin, muddying the picture of that era for a substantial region of the planet.

The skulls found in China were found to bear very close resemblances to those of Neanderthals, including a very similar inner ear bone and a prominent brow ridge. But the brow ridge was much less pronounced than one would expect from Neanderthals, with a considerably less dense cranium, as one might expect in an early H. sapiens. Researchers also found that the skulls were large by both modern and Neanderthal standards, with a whopping 1800 cubic centimeters of brain capacity.

So where do they fit in the grand scheme of things?

"The overall cranial shape, especially the wide cranial base, and low neurocranial vault, indicate a pattern of continuity with the earlier, Middle Pleistocene eastern Eurasian humans. Yet the presence of two distinctive Neanderthal features ... argue for populational interactions across Eurasia during the late Middle and early Late Pleistocene," said Dr. Trinkaus in a statement.

This kind of population mixing makes sense. We already know that modern humans and Neandertals interbred in Europe and that the geographic range of Neandertals stretched from Portugal to Teshik Tash, in Russia and Shanidar Cave, in Iraq.

The remains are dated to Marine Oxygen Isotope Stage 5d or 5e, making them between 105 and 125 ky in age.  Here is a description of the neurocranium from the paper:

The large Xuchang 1 neurocranium closely approximates the shapes of those of Middle Pleistocene humans, especially eastern Eurasians (Fig. 2 and fig. S17). The vault height is low, similar to those of the Neandertals and the higher Middle Pleistocene vaults, and the low vault height is reflected in a low temporal squamous portion (figs. S27 and S28). It is also produced by the very flat midsagittal parietal arc. In contrast, the maximum cranial breadth is the largest known in the later Pleistocene (fig. S15), and it is securely based on an undistorted posterior cranium. Moreover, the widest point is low, on the temporal bones (fig. S17), as in most earlier crania, rather than on the parietal bones, as among Neandertals and most modern humans. In addition, the one complete mastoid process is short and slopes inward (fig. S17), rather than being longer and more vertical, as in modern humans and some Neandertals. These features combine to provide the cranium with an occipital profile similar to those of earlier human crania, contrasting with the rounded profiles of Neandertals and the laterally vertical ones of modern humans.

There are a few things that are immediately interesting about this. First, this skull is YUGE.  1800 cc is monstrous.  The average cranial capacity of modern humans is around 1450 cc and that of Neandertals, around 1550 cc.  Second, the low, flat cranium with the widest point on the temporal bones (just above your ears) are traits of Homo erectus, not modern humans or Neandertals, suggesting strongly that there was some sort of continuity from this group through to modern humans in this region.  Neandertals simply don't have those traits.  Nonetheless, the cranium clearly shows some Neandertal traits in the ear and rear of the vault.  This continuity is characterized by the authors thus: "This morphological combination, and particularly the presence of a mosaic not known among early Late Pleistocene humans in the western Old World, suggests a complex interaction of directional paleobiological changes and intra- and interregional population dynamics."  As more information becomes available, we will have a better idea of how this find fits in the east Asian evolutionary picture.  This is exciting.  Up until this point, we have had very few finds in China that fall within this general time frame, most notably the Dali and Mapa remains.  I will have to rework my section on human origins for the BioLogos site for this region. 

More Evidence of Hybrization Between Archaics and Moderns in Africa

Nature's Research Highlights points to a paper written for the journal Genome Research, in which the authors, using whole genome analyses, argue that, for the first time, conclusive evidence of admixture between archaic Homo sapiens and early modern Homo sapiens occurred in Africa.  From the Nature blurb:

Michael Hammer at the University of Arizona in Tucson and his team analysed the entire genomes of seven individuals from two contemporary Western African Pygmy groups. The researchers identified 265 regions of the Pygmy genomes that may have been acquired through ancient interbreeding with other species, events that could have happened as recently as 9,000 years ago.

The article, itself, points out the nature of introgression in hominin evolution, thus:

Introgression, the transfer of genetic material between closely related species through hybridization, is an important and ubiquitous evolutionary force in both plants and animals (Mallet 2007). Although hybrids are often nonviable or infertile, hybridization can be an important driving force for the origin of novel traits and new species (Mallet 2007; Zinner et al. 2011). Within our genus, Homo, there is strong evidence for multiple introgression events between our own species, H. sapiens, and now extinct sister taxa outside Africa (Pääbo 2014). Neanderthal whole-genome sequencing (Green et al. 2010; Prüfer et al. 2014) revealed that Neanderthals contributed an average of ∼2% of the genetic variation of present-day humans living outside of sub-Saharan Africa. This gene flow likely took place 37–86 thousand yr ago (kya), after early modern humans emigrated from Africa and before archaic forms went extinct in Eurasia (Sankararaman et al. 2012), and it may have occurred multiple times (Vernot and Akey 2014, 2015; Kim and Lohmueller 2015).

It has been found, for example, that aspects of our immune system owe themselves to Neandertal introgression. This is an often overlooked aspect of how evolution proceeds.  There is continual debate about whether or not Neandertals represent a separate species from modern humans but the evidence that they interbred and exchanged genes is pretty good at this point.  The authors suggest that introgression of archaic genes occurred continually from the period of one million years down to less than 5 thousand years ago. That says something about the depth of the hybridization as well as the persistence of archaic genes in the modern human genome. 

40,000 Year-Old Bracelet Found at Denisova Cave

A bracelet has been discovered at the site of Denisova Cave that excavators have dated to c. 40,000 years BP.  Archaeology Hub has the story:

In what is quite an amazing discovery, scientists have confirmed that a bracelet found in Siberia is 40,000 years old. This makes it the oldest piece of jewelry ever discovered, and archeologists have been taken aback by the level of its sophistication.

The bracelet was discovered in a site called the Denisova Cave in Siberia, close to Russia’s border with China and Mongolia. It was found next to the bones of extinct animals, such as the wooly mammoth, and other artifacts dating back 125,000 years.

The cave is named after the Denisovan people — a mysterious species of hominins from the Homo genus, who are genetically different from both Homo sapiens and Neanderthals.

Here is the image of the bracelet from this site:

We know very little about the Denisovans, except that they coexisted with Neandertals and early modern humans and that their genetic fingerprint is present in modern-day Melanesian populations.  Here is a link to the National Geographic special that was done a few years back that covers the basics behind these mysterious hominins.  This find gives us a window into their culture. 

New DNA Information From Denisova Teeth

Many news outlets are reporting on new findings from the Denisova teeth that were discovered a few years ago.  Here is what the Chicago Tribune has to write:

According to a new analysis of a huge, recently-discovered fossilized molar, published Monday in the journal Proceedings of the National Academy of Sciences, the Denisovans lived for roughly 60,000 years in Asia alongside both Neanderthals, their close cousins, and more distantly related Homo sapiens - us. Their complicated genetic legacy suggests that they interbred with both species, and, possibly, with another hominid group that has yet to be discovered.

"The world at that time must have been far more complex than previously thought," Susanna Sawyer, an author of the study, told National Geographic. "Who knows what other hominids lived and what effects they had on us?"

It is taking us a bit long to wrap our brains around the fact that we are the only version of Homo on the planet now and have been for probably fifty thousand years. Prior to our ascendancy, there may well have been three or four related species—part of a syngameon—that occupied the landscape at approximately the same time and, as the researchers point out, likely interbred.  We know that archaic Homo sapiens in Africa interbred with the moderns there and that the moderns that left Africa interbred with the Neandertals and the Denisovans that they encountered.  One big happy family until we ruined the party.  More to come I am sure.

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. 

BioLogos Post: The Origins of Modern Humans, Part 1 Is Up!

The first of three posts on the origins of modern humans is up over at BioLogos.  As always, comments are welcome there and here.

HufPo: What We Learned About Human Origins In 2013 Will Blow Your Mind

The Huffington Post has a story on the advances in human origins for the last year.  In the realm of modern human origins:

Recent analyses of fossil DNA have revealed that modern humans occasionally had sex and produced offspring not only with Neanderthals but also with Denisovans, a relatively newfound lineage whose genetic signature apparently extended from Siberia to the Pacific islands of Oceania.

This year, hints began emerging that another mystery human lineage was part of this genetic mix as well. Now, the first high-quality genome sequence from a Neanderthal has confirmed those suspicions.

These findings come from Denisova Cave in southern Siberia, where the first evidence of Denisovans was discovered in 2008. To learn more about the Denisovans, scientists examined DNA from a toe bone unearthed there in 2010.

The researchers found that the fossil belonged to a Neanderthal woman. Her DNA helped refine the human family tree, as it revealed that about 1.5 to 2.1 percent of the DNA of modern people outside Africa is Neanderthal in origin, whereas about 0.2 percent of DNA of mainland Asians and Native Americans is Denisovan in origin. [Top 10 Mysteries of the First Humans]

As Dennis Venema points out, modern humans appear to come from a population of around 150,000, which likely arose in North Africa.  I would still suggest two possibilities that might explain the hybridization.  One, that from around this time to 50 thousand years ago, humans existed as a generally polytypic species and that interbreeding, until the demise of the Neandertals and the Denisovans was, perhaps, widespread.  In the 50 thousand years since then, these genes have stochastically dropped out of the population.

The other possible model that would explain the variation between Neandertals, Denisovans and early moderns might be a syngameon, in which there are three definable species that, at their peripheries, hybridize.  At some point, then, the modern humans simply swamped the other two genomes. This would be the model of modern-day dogs and wolves which can mate but ordinarily do not. 

Another finding?  That early Homo may have been one highly-variable species, rather than a bush of species:

The level of variation seen in Homo fossils is typically used to define separate species. However, analysis of 1.8-million-year-old skulls excavated from the Republic of Georgia revealed the level of variation seen among those skulls was about the same as that seen among ancient African Homo fossils. As such, researchers suggest the earliest Homo fossils may not be multiple human species, but rather variants of a single lineage that emerged from Africa.

This will rattle those that hold to more cladistically-driven models of human origins like Ian Tattersall who supports a model more like the phylogenetic species concept, in which  single trait difference might confer species-level taxonomy.  This takes care of this issue of why there are two very different morphs on the landscape in East Africa at this time, represented by ER 1813 and ER 1470.  The dimorphism is quite large, but, as we discovered, is not beyond what would be expected in any species of large-bodied hominoid but larger than what would be found in any living population of humans in the last several hundred thousand years. 

A good run-down.  Read the whole thing. 

More Trouble for the Complete "Out-of-Africa" Model

Science Daily is reporting on research done on migration patterns involving early anatomically modern humans.  They write:

The team, led by Johannes Krause from Tübingen University, was able to reconstruct more than ten mitochondrial genomes (mtDNAs) from modern humans from Eurasia that span 40,000 years of prehistory. The samples include some of the oldest modern human fossils from Europe such as the triple burial from Dolni Vestonice in the Czech Republic, as well as the oldest modern human skeletons found in Germany from the site of Oberkassel close to Bonn.

The researchers show that pre-ice age hunter-gatherers from Europe carry mtDNA that is related to that seen in post-ice age modern humans such as the Oberkassel fossils. This suggests that there was population continuity throughout the last major glaciation event in Europe around 20,000 years ago. Two of the Dolni Vestonice hunter-gatherers also carry identical mtDNAs, suggesting a close maternal relationship among these individuals who were buried together.

It was also suggested that the split between non-Africans and Africans was much later in time, between 62 and 95 ky BP. This would mean that the window of hybridization would be much larger than originally thought and that archaic and modern hybridization was a good deal more common until a later time than thought.  The first moderns that we have are from the site of Bouri, in the Afar Triangle, and date to around 160 ky BP.  Maddeningly, what we are lacking is good material between that time and around 100 ky BP, when the Near Eastern Skhul and Qafzeh material are found.  A friend of mine and I argued that the archaic traits in those skulls represent African archaic traits and not hybridization with Neandertals.  This would seem to support that.  They suggest that there are discrepancies between these results and previous ones but, critically, that these results tend to support both the palaeoanthropological and archaeological evidence.    Here is the citation:

Fu et al., A Revised Timescale for Human Evolution Based on Ancient Mitochondrial Genomes,
Current Biology (2013), http://dx.doi.org/10.1016/j.cub.2013.02.044

New BioLogos Post: The Rise of Archaic Homo sapiens

My newest BioLogos post is up, called The Rise of Archaic Homo sapiens.  Comments are welcome.

Science & Human Origins: A Not So Positive Review by Paul McBride

Douglas Axe, Ann Gauger and Casey Luskin have a new book out called Science & Human Origins. I have not had a chance to pick it up yet but it looks like the authors have learned nothing from the recent exchanges with folks like Dennis Venema and PZ Myers. The same faulty ideas still hold sway. Paul McBride has reviewed the book here. McBride points out an immediate problem that seems to characterize the ID camp in general. Ann Gauger writes:

I personally am convinced that unguided, unintelligent processes can’t do the job, not only because the neo-Darwinian mechanism is utterly insufficient, but also because we are beings capable of intelligence and creativity.

This is argument from personal incredulity and has no place in scientific discourse. If this is indeed how she feels, then it must color how she does her experiments and how she gathers her conclusions. If she is not open to this possibility, she has no business writing this book.

McBride remarks that chapter two, which is written by Douglas Axe, discusses his and Gauger's recent work where it was found that the time necessary to get one protein to evolve into another, contemporaneous protein is longer than the universe has existed. Other researchers have pointed out the logical error in this experiment but McBride's statement is succinct:

If Gauger and Axe couldn't get a single protein to evolve a novel function of their choosing then surely massive evolutionary changes are impossible. Actually, no. Gauger and Axe's experiment is a profound misunderstanding of evolution. The real question is not "Can X be turned into Y?" because that sense of direction requires preordination, which is not theorised to be a part of evolution. If we remove this preordination, the question becomes "Can X turn into something else?".

It is more than a little ironic that Axe and Gauger argue that, left to its own devices, evolution cannot foster new genetic material due to its randomness and then, to show that this is so, introduce an experiment in which evolution is directed and non-random. Didn't any of the editors catch this? Axe and Gauger do not seem to understand the concepts of exaptation and neutral mutations.

Casey Luskin wrote the chapter on the fossil record. McBride quotes Luskin:

There are many gaps and virtually no plausible transitional fossils that are generally accepted, even by evolutionists, to be direct human ancestors. Thus, public claims of evolutionists to the contrary, the appearance of humans in the fossil record appears to be been anything but a gradual Darwinian evolutionary process. The Darwinian belief that humans evolved from apelike species requires inferences that go beyond the evidence and is not supported by the fossil record.

Luskin isn't listening. He has shut his ears and refuses to listen to what people are saying about the evidence. As I will remark in my next BioLogos posts (and something McBride points out), the earliest Homo erectus individuals have cranial capacities of around 700 cc³, while the later ones have cranial capacities of up to 1225cc³. Does this overlap those of modern humans? Barely. And the suite of characteristics that are on display in your average Homo erectus are not modern human in any way. They are getting there, but they are not there yet. Then we have archaic Homo sapiens, such as Kabwe from what is now Zimbabwe, which is obviously evolved over Homo erectus but not quite modern human either. These people show up in Asia (Dali and Mapa in China and Ngandong in Indonesia), Europe (Petralona, Swanscombe, Steinheim, Atapuerca, to name a few) and they are obviously intermediate between Homo erectus and Homo sapiens in some way. Are they direct ancestors? Maybe, maybe not, but they are transitional. Luskin is arguing unilineal ancestry without allowing for the possibility of collateral ancestry.

The earliest modern remains that we have are from the site of Herto, on the Bouri Peninsula in the Afar triangle, in Ethiopia and they date to around 160,000. Even so, there are a few characteristics that link these remains to earlier, archaic Homo sapiens. There may be no absolute evidence that these represent our ancestors, but who is to say they aren't? We know that we have modern humans in the Near East at 100,000 that still show some signs of not being quite like us. By 40,000 they do. If these are not transitional sequences, what would qualify?

McBride's conclusion contains the following paragraph:

I have been left wondering why the Discovery Institute, or intelligent design advocates in general, or biblical literalists feel a need to try and accommodate science when they have a belief in a supernatural entity capable of breaking natural laws. In the case of this book, it has left them needing to make all kinds of awkward criticisms of fields in which the authors clearly lack expertise. A lawyer is not the right guy to challenge the world's palaeoanthropologists, nor the world's geneticists. Certainly, he shouldn't be trying to take them all on at once. It will end with him trying to smear the reputation of scientists rather than engaging with their ideas. Accusations that the entire field of palaeoanthropology is driven by personal disputes and that Francis Collins is a bad Christian are simply not compelling reading in a book that is putatively about scientific argument.

Leaving aside the issue of miracles, since I believe they can and do happen and are not restricted to the physical, observable world, McBride is partly correct in his assessment about the abilities of these authors to address the material. The problem is deeper than that, however. At least in the case of Luskin, there is an unwillingness to alter one's viewpoints in the face of additional evidence to the contrary. Here, there is a distinct similarity to the young-earth creationist camp, who have little to no scientific integrity. As McBride points out, Luskin's views have not altered since 2006. I pointed out these problems two years ago in a BioLogos post. I know that he read the post because we corresponded briefly about it. It is therefore, doubly disconcerting that he would continue to hold onto this “no transitional fossils” idea as if it were still defensible.

This is a book I clearly need to pick up and read, although I am quite certain it will just make my blood boil to do so.

New Hominin Finds in China

In somewhat hyperbolic terms, Discovery News reports on “Mysterious Dark-Skinned Stone Age People Found.” Jennifer Viegas writes:

A newly found Stone Age people featured darker skin, an unusual mix of primitive and modern features and had a strong taste for venison.

Remains of possibly four individuals of the so-called "Red Deer Cave People" were unearthed in southwest China and may represent a new species of human.

The fossils from two caves, date to just 14,500 to 11,500 years ago. Until now, no hominid remains younger than 100,000 years old have been found in mainland East Asia resembling any other species than our own. "We have discovered a new population of prehistoric humans whose skulls are an unusual mosaic of primitive, modern and unique features -- like nothing we've seen before," said Darren Curnoe, associate professor in the School of Biological, Earth & Environmental Sciences at the University of New South Wales and lead author of a study about the find in the journal PLoS One.

Curnoe wrote about the finds in 2009:

While the material falls within the range for modern human variation, the individuals show some archaic features and are robust. Only a handful of potential stone tools have been recovered from the site; many are hammer stones.

It would be quite peculiar if this were another species of human, although the evolutionary picture is getting muddy in Europe, so it stands to reason that it should be muddy in Asia, especially given that we have the Denisova evidence. In the PLoS article (http://dx.doi.org/10.1371/journal.pone.0031918) the authors remark that it is possible that they represent a late-surviving archaic group or that the Homo sapiens populations that were coming out of Africa were remarkably diverse morphologically and that these individuals represent a more primitive population of those migrants. There is reasonably good evidence that there were different groups that migrated to East Asia over the course of the last million or so years and this group may simply reflect one.

It is an odd mix of traits to be sure. The brain case is somewhat low (http://dx.doi.org/10.1371/journal.pone.0031918.g005), and yet the mandibles have chins, a late-arriving characteristic, only present in modern humans. Additionally, the face is flat(http://dx.doi.org/10.1371/journal.pone.0031918.g003) and there is no space behind the last molar, indicating modernity. Either way, it is fascinating find but the headlines are unnecessarily over-the-top. Read the whole article.

Aside: Curnoe is a splitter with the best of them and in the mould of Bernard Wood. He was responsible for a new species of Homo, in South Africa, Homo gautengensis, because he felt that the remains differed from other specimens of early Homo enough to give them their own species designation. This name has not had traction in the palaeoanthropological community.

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Neandertals Found on the Greek Islands

They are sunny, tranquil and surrounded by gorgeous blue-green ocean. They are the Greek isles and now, it seems, they were also home to a population of Neandertals. The Greek Reporter writes:

Meganisi – a small and beautiful strip of land four miles south-east of Lefkada- is part of the group of small islands called Prighiponisia, among which is the famous Skorpios owned by the Onassis family.

On the basis of elements brought to light during excavations, Meganisi’s first inhabitants – according to archaeologists – were Neanderthal men and women living in that part of the Ionian Sea 100,000 years ago in a period scholars call the Mid-Paleolithic Era. The archaeological discovered on the island of Meganisi provide evidence of the presence of human beings in the Mesolithic Period, which with small intervals cover many millennia to the late Roman period.

This is not much of a surprise. The Greek islands are not very far apart and we already know that archaic Homo sapiens were in Greece some 250-300 thousand years ago as represented by the Petralona skull (below) and some other finds.

If I had the chance to live on those islands, I would, too.



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“Out-of-Africa Replacement Model”: Piling On

On the heels of the recent DNA arguments supporting hybridization between early modern Homo sapiens and archaic Homo sapiens in Africa comes fossil skeletal evidence.  As the Telegraph reports:

A study on human remains found in the Iwo Eleru cave in Nigeria, West Africa, shows that Stone Age humans in the area shared characteristics with much older human relatives. Palaeontologists leading the study believe their findings provide evidence that modern humans and older subspecies of human might have coexisted and even crossbred in Africa. The findings add weight to theories that ancient species of human lived alongside the anatomically modern humans after they first appeared in Africa 200,000 years ago.

Quoted in the article is Chris Stringer, one of the progenitors of the Out-of-Africa replacement model of modern human origins which was based on mitochondrial DNA studies done in the late 1980s.The article continues:

Professor Stringer said: "The majority view was that once modern humans emerged in Africa 150,000 years ago, it was kind of the end of the story and modern humans took over. "I think the reality is that the ancestral forms didn't just disappear but hung around alongside those that had evolved into modern humans. "Somewhere lurking in bits of Africa were these more archaic people and we are starting to get a picture of that."

I suspect that it is going to get very hard to pin down exactly where Homo sapiens starts. It is becoming more and more clear that anatomically modern Homo sapiens and archaic Homo sapiens went for the occasional “roll in the hay.” If so, as I pointed out earlier, there simply was no “speciation event.” This goes more to supporting the multiregional evolution model, as it applies to Africa, in which there was selection for more modern genes. This model may also apply to Europe, with the mixing of modern humans and archaic humans there. I suspect that this will spur reexamination of the early modern material from there, such as Mladeč, where the material dates from the Early Würm/Late Würm interglacial period.

R.I.P. Out-of-Africa Replacement Model?

"When two groups of people meet, they may fight but they will always mate." 

-J. Lawrence Angel

It now seems that the last bastion of uniqueness for modern humans as a species is crumbling.  If true, this is huge news.  Science Daily is reporting that even after their origination in Sub-Saharan Africa, modern humans may have interbred with archaic Homo sapiens.  They write:

In a paper published in the Proceedings of the National Academy of Sciences (PNAS), a team led by Michael Hammer, an associate professor and research scientist with the the University of Arizona's Arizona Research Labs, provides evidence that anatomically modern humans were not so unique that they remained separate. "We found evidence for hybridization between modern humans and archaic forms in Africa. It looks like our lineage has always exchanged genes with their more morphologically diverged neighbors," said Hammer, who also holds appointments in the UA's department of ecology and evolutionary biology, the school of anthropology, the BIO5 Institute and the Arizona Cancer Center.

This wasn't done by comparing modern DNA with ancient DNA, however.   They write:

First, the team sequenced vast regions of human genomes from samples taken from six different populations living in Africa today and tried to match up their sequences with what they expected those sequences to look like in archaic forms. The researchers focused on non-coding regions of the genome, stretches of DNA that do not contain genes, which serve as the blueprints for proteins. "Then we asked ourselves what does the general pattern of variation look like in the DNA that we sequenced in those African populations, and we started to look at regions that looked unusual," Hammer said. "We discovered three different genetic regions fit the criteria for being archaic DNA still present in the genomes of sub-Saharan Africans. Interestingly, this signature was strongest in populations from central Africa." The scientists applied several criteria to tag a DNA sequence as archaic. For example, if a DNA sequence differed radically from the ones found in a modern population, it was likely to be ancient in origin. Another telltale sign is how far it extends along a chromosome. If an unusual piece is found to stretch a long portion of a chromosome, it is an indication of being brought into the population relatively recently.

Aside from the assumptions that go into such research, it will likely send shock waves through the discipline, and will certainly require the revision of some cherished models concerning the origins of our species. It certainly rules out the idea that there was a speciation event in a cladistic sense and stretches our species back much further than we had originally thought.  Look for these results to be challenged soon.

Another Species of Homo??

There is, if you believe the work coming out of Max Planck Institute. According to an article in Der Spiegel:

The human family just got a new relative. Genetic researchers in Leipzig have deciphered the DNA of a hominid species that coexisted with Homo sapiens and Neanderthals around 40,000 years ago. A tiny piece of bone was enough for them to sequence the genome.

The miniscule amount of powder could have sat on a knife point, and yet, according to Johannes Krause, it contains something sensational. The Leipzig-based genetic researcher extracted the fine powder from a minute piece of fossilized bone -- and discovered a whole chapter of mankind's history inside it.

One wonders why the remains of such have not been found. No matter. Onward. This is a follow-up to a story that, somehow, escaped my notice earlier this year, the discovery of the Denisova girl. She, apparently is the representative of a new species of Homo that split off from the main line around 300,000 years ago, and lived in the steppes and Siberia. The speculations are almost lurid:

The scientists posed the question as to how different types of hominids might have interacted with each other. Did they hunt each other? Did they avoid each other? Might they have stolen each other's women? To find the answers to these questions, the Max Planck scientists compared DNA from the Denisova cave with that of modern man. They found no traces of Denisova characteristics in people from Africa, Europe or China. Indeed, clear indications of intermingling were only found among the inhabitants of Papua New Guinea.

The two types of hominids, researchers believe, must have encountered each other somewhere in Southeast Asia. They hypothesize that different Denisova tribes had settled there long before modern man made his way to East Asia some 30,000 years ago. The two groups must have interbred, perhaps not as a matter of course, but periodically. Later, the modern humans and their genetic dowry moved further south, whence today's Melanesians developed.

The Leipzig researchers now want to search Russian and Chinese collections for more fossils that could belong to the Denisova. The hope is to understand what they may have looked like. While the DNA provides hints on several characteristics of the Denisova, appearance is not one of them.

This is not out of the question, since hominids in this time range all belong to that kitchen sink, catch-all grade “archaic Homo sapiens,” which encompasses basically everything that succeeded Homo heidelbergensis up to modern Homo sapiens. It also means that the human family tree is considerably more bushy than we thought at this point in time.

On the other hand, if they found traces of intermingling with Melanesians and other Asian groups, it is not clear how “specific” these individuals were. The original authors have remarked that the Denisova girl represented an out-of-Africa migration, a conclusion that has been challenged by Martinón-Torres et al. ¹ These authors write:

The evidence that the ancestors of Neanderthals (i.e., H. heidelbergensis) left Africa ca. 500–300 ka is currently inconclusive, and the origin of H. heidelbergensis remains enigmatic. Whilst dispersals out of Africa might have occurred ca. 1.0 Ma, large-scale dispersals within Asia were also probable, and thus an Asian origin of the Denisovans cannot be excluded. These issues cannot be resolved without substantial improvements in the dating of key specimens, without an enlarged Asian fossil hominin record (particularly from SW Asia), and without a much more detailed Middle Pleistocene climatic record from SW Asia and NE Africa. Although the Denisova evidence is undoubtedly a fascinating piece in the jigsaw puzzle of human origins, it would be premature at present to determine the part of the picture to which it belongs.

Given what we know about Neandertal DNA showing up in the modern human genome, the remains from Denisova may yet suggest a very wide-range polytypism in the human record during the transition from archaic to modern Homo sapiens.


¹Martinón-Torres, M., Dennell, R., & Bermúdez de Castro, J. M. (2011). The Denisova hominin need not be an out of Africa story. Journal of human evolution, 60(2), 251-255.

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Dan Margoliss on Glenn Beck and Evolution

Dan Margoliss of the Morning Star UK has an issue with Glen Beck, who took a pot shot at evolution the other day:

"I think [evolution's] ridiculous," Beck said recently on his radio show. He went on to make a number of statements to bolster his claim that Darwinian natural selection is nonsense - but his claims showed only how little he knows of the subject.

Well, he wouldn't be the first conservative talk show host that completely botched evolutionary theory. Fox news regularly has on people like Kirk Cameron who doesn't know the first thing about the subject. Along the way, though, Margoliss writes something involving the human fossil record that, I will venture, is completely unknown to this group of evolution-haters:

We are Homo sapiens. The species before us was Homo erectus. If you were to revive a Homo erectus and put him next to a modern human being, it would be easy to tell the difference which was which.

However, if you were to revive all of our preceding generations and put one member of each in line, until it reached the generation of our recently revived ancestor Homo erectus, you'd have a problem of classification.

It would be virtually impossible to mark where Homo erectus ended and where Homo sapiens began. Each generation would be slightly more like the next species than the previous one.

Evolution is a process of gradual change - very gradual - over thousands of generations. It's not as if a Homo erectus gave birth to a Homo sapiens. Every single generation is, in a sense, intermediate.

It's precisely because whole generations are missing that we are able to label the different species. Otherwise we'd have no idea where to draw the line between humans and our ancestors.

Some would argue that Homo erectus did not give rise to Homo sapiens and that Homo sapiens neandertalensis is a separate species, but I will follow Wolpoff on this lead.

When Kirk Cameron stood there in front of the cameras and said he couldn't possibly believe in evolution because he had never seen "one of these, a crockaduck," I thought he was joking. Then I realized that this level of knowledge about evolutionary theory is commonplace.

The human fossil record is so good and there are so many transitions that we have trouble telling one species apart from another. Is the Bodo cranium (shown here on the left) late Homo erectus or is it archaic Homo sapiens? I have seen it classified as both. The point is that evolution happens in mosaic fashion, regardless of whether you employ a systematics model or a phenetic one. The fossil record is what it is and for humans and their precursors, it is quite good.



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