Artist's impression of hominin gut microbiota.
Image credit: The University of Texas at Austin. Illustration by Jenna Luecke
Cospeciation of gut microbiota with hominids | Science
Further confirmation that scientists have the hominid family tree about right in terms of time and branching has been provided in a paper published today in
Science. It shows that some of the symbiotic bacteria we carry in our gut today have been with not only us but our close relatives from before we diverged into the different African apes and humans, and that they diverged and speciated at the same time.
This isn't really a surprise to evolutionary scientists because that is exactly what we would expect to happen. Mere confirmation of what is already known from the fossil and genetic evidence would scarcely raise an eyebrow and might not even be considered worth publishing. But, from a scientific point of view, the interesting thing here is that we don't, as was thought, acquire all our gut microbiota from our general environment. At least some of it seems to be inherited, hence forming a relatively isolated genetic line which has been maintained in the different diverging species over hundreds of thousands of generations.