Modern speech gene found in Neanderthals

[Exeter]

Genetic studies hint Neanderthals were equipped for language.
Kerri Smith

Did Neanderthals communicate with a real language?CHRISTIAN JEGOU PUBLIPHOTO DIFFUSION/ SCIENCE PHOTO LIBRARY


Researchers delving into the DNA of Neanderthal remains have found the human form of a gene crucial for the development of language.


The result indicates that this modern form of the gene could have appeared much earlier than previously thought — in the ancestors of humans and Neanderthals. However, the presence of this gene alone does not guarantee that Neanderthals actually spoke to each other using anything that we would classify as a language. Studies of their anatomy haven’t answered this question either: a bone in the Neanderthal throat called the hyoid resembles the human form, but the inner ear appears different.


It is extremely difficult to extract nuclear DNA from such ancient samples, so the study is an impressive technical achievement. But the group cannot rule out entirely the possibility that their results are due to contamination of the samples with modern human DNA. One of the first studies of Neanderthal DNA1, published in Nature in 2006, was reanalysed this year and it was claimed that a large chunk could have been modern human DNA, not Neanderthal2.

Of chimps and men

In the new study, Johannes Krause of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany and an international team of colleagues took DNA from two Neanderthal males whose bones were found in a cave in Northern Spain.


The team then looked specifically for the sequence of a gene called FOXP2 among the DNA from the bones — a gene known to be related to language. It isn't clear exactly what FOXP2 does, but in humans, mutations in this gene are known to cause a severe language problem in which affected individuals cannot grasp grammar and do not have the ability to control mouth movements to make words3.


Krause expected to find that the Neanderthal version of the gene looked like the ‘ancestral’ form, as found in chimpanzees, rather than the newer human version, which differs in two places from the chimp FOXP2 . But the human changes appeared in the Neanderthal DNA too. “Most, including us, would have said that this gene would have looked more ancestral,” says Krause. “The Neanderthals surprised us there a bit.” The team publish their results in Current Biology 4.


It’s hard to say what this means for the linguistic aptitude of our Neanderthal cousins. “The status of FOXP2 in Neanderthals is not by itself sufficient for us to resolve the big question of whether or not they were capable of speech,” says Simon Fisher, a neuroscientist who studies FOXP2 at the University of Oxford’s Wellcome Trust Centre for Human Genetics.
Dirty bones

The group admits that there are other possible explanations for their results: it could be that they are sampling the offspring of Neanderthal and human mating, so that humans gave the Neanderthals in question the modern FOXP2 gene. Or it could possibly be due to contamination in the field or the lab.


Krause and his colleagues note that they took steps against contamination: they used samples from Neanderthal individuals that had been excavated in sterile conditions and immediately frozen; and they looked at several other areas of the genome where humans and Neanderthals are known to differ, to make sure that what they examined was truly the Neanderthal sequence.
But to rule it out entirely as a possibility is very difficult, says Jeffrey Wall, an evolutionary geneticist at the University of California, San Francisco, who led the reanalysis of the original Nature paper.


Krause is excited about what else they might find once they use their approach to look for more genes, including those related to other traits of interest such as brain size and hair colour.

• References
  1. Green, R. et al. Nature 444, 330–336 (2006).
  2. Wall, J. D. & Kim, S. K. PLoS Gen. 3, e175 doi:10.1371/journal.pgen.0030175 (2007).
  3. Lai C. et al. Nature 413, 519 - 523 (2001).
  4. Krause J. et al. Curr. Biol. 17, doi:10.1016/j.cub.2007.10.008 (2007)

Modern speech gene found in Neanderthals : Nature News