If you’ve ever considered a pedicure from a scientist, think again – for one digit may reveal your entire genome.
That’s precisely what occurred when paleontologists got hold of a toe bone belonging to a female Neanderthal who left her appendage behind in a cave in the Altai Mountains of Siberia. She’d probably be shocked to know that 130,000 years later, we are privy to her family’s social life and now know she was highly inbred.
The study, published online in Nature in December 2013, describes how this new Neanderthal genome contains evidence that points to a greater amount of interbreeding between ancient human populations than previously realized.
Perhaps the phrase, ‘kissing kin’ originated early on – this particular Neanderthal’s parents were found to be half-siblings and her two parental gene sets were close to identical for long stretches of generations.
“We thought it would be a Denisovan toe,” said Dr. Paabo, from Max Planck Institute for Evolutionary Anthropology, “but it very clearly was a Neanderthal.” Denisovans, another line of human precursor, were discovered when scientists reconstructed the genome from an 80,000-year-old finger bone retrieved from a cave called Denisova.
Dr. Paabo and his team compared modern human DNA to rough drafts of the Denisovan and Neanderthal genomes. They found that modern humans, Neanderthals, and Denisovans all descended several hundred thousand years ago from a common ancestor. They also discovered some Neanderthal and Denisovan DNA in the genomes of living humans – a good fact to have on hand to explain spousal behaviors.
Dr. Paabo and his colleagues concluded that modern humans interbred with both Neanderthals and Denisovans before those two lineages became extinct. “We don’t know if this is typical of all Neanderthals, or just this population in Siberia,” said Dr. Paabo. It is thought that it will take more superior Neanderthal genomes to answer that question.
Paabo et al. 2013
The fossilized toe bone of a Neanderthal who lived in Siberia 130,000 years ago offers a complete genome of this human ancestor.
If scientists were sequencing the DNA of a living person, they would find a similar accuracy in the quality of this Neanderthal’s genome. This new Neanderthal genome is described like a genetic encyclopedia – an entire book contained in a toe.
Prüfer, K., Racimo, F., Patterson, N., Jay, F., Sankararaman, S., Sawyer, S., … & Pääbo, S. (2014). The complete genome sequence of a Neanderthal from the Altai Mountains. Nature, 505(7481), 43-49.
The Paleontological Research Institution, Ithaca, New York, is pleased to sponsor Paleontology content for This View of Life. Founded in 1932, PRI has outstanding programs in research, collections, and publications, and is a national leader in development of informal Earth science education resources for educators and the general public.