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Adam and the Genome and Neanderthal Cave Art

Neanderthal

As if on cue, science news today reports a remarkable discovery: cave art in Spain from upwards of 64,000 years ago, apparently by Neanderthals. The Wall Street Journal aptly summarizes the takeaway:

Neanderthals, once considered the low-brows of human evolution, may have been among the world’s first artists, creating cave paintings long before modern humanity arrived on the scene…

“Once considered”? This is timely because in the book Adam and the Genome, which we’ve been reviewing here, theistic evolutionist and biologist Dennis Venema discusses DNA that has been extracted from fossils of extinct members of the genus Homo, including Neanderthals and the recently discovered Denisovans. He claims these groups were “not members of our own species” (p. 62). Yet apparently, they were so genetically similar to humans that we could interbreed with them.

And Neanderthals, as the journal Science now reports, had the capacity to create art. In the photo above, that is what looks like a ladder, suggesting that the artist was capable of “a much richer symbolic behavior than previously assumed.” The paintings, in three separate caves, are evidently not by “modern humans” since the latter would not reach Europe for another 20,000 years.

Very interesting. We have virtually no fossil evidence for Denisovans, so it cannot be said that they represent a non-human-like form. As for Neanderthals, here we have plenty of fossil evidence, and what we know shows that they were virtually indistinguishable from modern humans. Dennis Venema notwithstanding, some would consider Neanderthals to be members of our own species.

Casey Luskin explains in “The Genus Homo: All in the Family”:

Though Neanderthals have been stereotyped as bungling, primitive precursors to modern humans, in reality they were so similar to us that if a Neanderthal walked past you on the street, you probably wouldn’t notice many differences. Wood and Collard make this same point in drier, more technical language: “The numerous associated skeletons of H. neanderthalensis indicate that their body shape was within the range of variation seen in modern humans.”

He concludes:

We saw earlier that Leslie Aiello said “Australopithecines are like apes, and the Homo group are like humans.” This is consistent with what we see in the major groups of Homo like H. erectus and Neanderthals. According to Siegrid Hartwig-Scherer, the differences between these humanlike members of the genus Homo can be explained as microevolutionary effects of “size variation, climatic stress, genetic drift and differential expression of [common] genes.” These small differences do not supply evidence of the evolution of humans from earlier ape-like creatures.

Now exactly what the DNA evidence of Neanderthals and Denisovans means for Adam and Eve is still not completely clear. Here’s how Ann Gauger, Ola Hössjer, and Colin Reeves interpret Denisovan and Neanderthal DNA in their chapter “An Alternative Population Genetics Model” in the book Theistic Evolution: A Scientific, Philosophical, and Theological Critique:

Archaic Populations, Humans or Not? As mentioned in Section 4, significant fragments of Neanderthal and Denisovan DNA have been found among present day humans, so researchers suggested that some interbreeding took place between archaic populations and the ancient humans that supposedly emigrated out of Africa. This admixture is believed to have happened at least 50 000 years ago, and probably later on as well. It is in fact well known that gene flow between closely related populations is helpful in order to increase genetic variability and to avoid inbreeding, and indeed, the archaic introgression is believed to have had positive effects, like helping the Tibetans to adapt to high altitudes, and the non-Africans in general to adapt to colder temperature and to ward off infections. But the common descent model predicts a split between humans and archaic hominins more than 500 000 years ago. It would therefore be remarkable if two populations, after such a long time of separation, were still able to have fertile offspring.  But even if this were possible, because of the long separation, it is reasonable to believe that the offspring had low fitness, since our archaic ancestors had, most likely, accumulated many alleles which were deleterious for humans, before the admixture took place.

In view of this, it seems that the large fraction of archaic DNA among present-day humans is more reconcilable with a unique origin model, in which Neanderthals and Denisovans are descendants of Adam and Eve and hence our fully human relatives.

Even if they did exist as groups that were distinct from our own species, Homo sapiens, that in no way precludes the possibility that Adam and Eve were real people who were the progenitors of all modern humans.

Photo credit: Cave art by Neanderthals? C.D Standish, A.W.G. Pike and D.L. Hoffmann, via Science Daily.