PDA

View Full Version : Detecting ancient positive selection in humans using 1 extended lineage sorting



paoloferrari
07-27-2017, 07:55 AM
Detecting ancient positive selection in humans using extended lineage sorting

http://genome.cshlp.org/content/early/2017/07/18/gr.219493.116.full.pdf+html

"ABSTRACT
8
Natural selection that affected modern humans early in their evolution has likely shaped some of the
9
traits that set present-day humans apart from their closest extinct and living relatives. The ability to
10
detect ancient natural selection in the human genome could provide insights into the molecular basis
11
for these human-specific traits. Here, we introduce a method for detecting ancient selective sweeps by
12
scanning for extended genomic regions where our closest extinct relatives, Neandertals and
13
Denisovans, fall outside of the present-day human variation. Regions that are unusually long indicate
14
the presence of lineages that reached fixation in the human population faster than expected under
15
neutral evolution. Using simulations we show that the method is able to detect ancient events of
16
positive selection and that it can differentiate those from background selection. Applying our method
17
to the 1000 Genomes dataset, we find evidence for ancient selective sweeps favoring regulatory
18
changes and present a list of genomic regions that are predicted to underlie positively selected human
19
specific traits. "