Human evolution; more evidence of interbreeding (Introduction)

by David Turell , Thursday, August 06, 2020, 19:54 (1358 days ago) @ David Turell

Another unknown species appears in new DNA study:

https://phys.org/news/2020-08-dna-ancient-unidentified-ancestor-humans.html

"A new analysis of ancient genomes suggests that different branches of the human family tree interbred multiple times, and that some humans carry DNA from an archaic, unknown ancestor. Melissa Hubisz and Amy Williams of Cornell University and Adam Siepel of Cold Spring Harbor Laboratory report these findings in a study published 6th August in PLOS Genetics.

"In the new paper, the researchers developed an algorithm for analyzing genomes that can identify segments of DNA that came from other species, even if that gene flow occurred thousands of years ago and came from an unknown source. They used the algorithm to look at genomes from two Neanderthals, a Denisovan and two African humans. The researchers found evidence that 3 percent of the Neanderthal genome came from ancient humans, and estimate that the interbreeding occurred between 200,000 and 300,000 years ago. Furthermore, 1 percent of the Denisovan genome likely came from an unknown and more distant relative, possibly Homo erectus, and about 15% of these "super-archaic" regions may have been passed down to modern humans who are alive today.

"The new findings confirm previously reported cases of gene flow between ancient humans and their relatives, and also point to new instances of interbreeding. Given the number of these events, the researchers say that genetic exchange was likely whenever two groups overlapped in time and space. Their new algorithm solves the challenging problem of identifying tiny remnants of gene flow that occurred hundreds of thousands of years ago, when only a handful of ancient genomes are available."

Comment: based on current humans sexual activity is always possible. Each group contributed something useful to our DNA