by Jamie Henzy
Figure 1. This comparison of skulls from a modern human (left) and Neanderthal (right), from the Cleveland Museum of Natural History, shows the larger cranial capacity of Neanderthals. Source.
From the discovery of the first Neanderthal skull in a Belgian cave in 1826, a bone of contention among Homo sapiens has been the extent of our relationship to Homo neanderthalis, who disappeared from the fossil record ~30,000 years ago. Like scrappy cousins we'd rather not claim, we've attempted to distance ourselves and establish our clear superiority, leading at times to suspect interpretations of data. For example, Neanderthal cranial capacity was larger than ours by about 25% (1500-1800 cc, compared to 1300-1500 cc for modern humans). To an unbiased observer, this feature could imply greater intelligence among Neanderthals. However, we have often chosen to depict Neanderthals as grunting brutes whose large heads evolved to allow frequent head-butting, as well as protection from blows from each others' clubs. But history is written by the winners, and as long as bones couldn't talk, we were free to impose upon them our preferred narrative.
Figure 2. The subpopulation of humans that left Africa for parts of Europe and Asia encountered Neanderthals and interbred with them, resulting in Neanderthal genetic sequences in modern non-African populations. Source.
Neanderthals Meet the Genomic Era
These days, however, the Genomics Age has given voice to the Stone Age, as Neanderthal DNA from 38,000 to 45,000 years ago has been successfully extracted from teeth and bone marrow, sequenced, and assembled, providing a map of the Neanderthal genome. Several findings require adjustments to the grunting brute narrative. First of all, Neanderthals share with humans the exact variant of a gene, FOXP2, that when absent in humans results in an inability to speak and process language. This allele is not found in chimps and gorillas—our closest living relatives—and along with archeological evidence of symbolic behavior, strongly suggests that they used language. Moreover, materials extracted from Neanderthal teeth indicate that they ate cooked vegetables. And the notion that ancient humans and Neanderthals represented separate species was dealt a blow when it was discovered that 1-4% of the genomic sequence of modern Europeans and Asians was contributed by Neanderthals, strongly suggesting that Neanderthals and the ancestors of modern humans interbred and produced fertile offspring. No separate species, they. In fact, some of the gene variants contributed by Neanderthals are thought to have aided the immune system of early humans.