Why do traces of the "Simian Shelf" exist in certain races??

Question

Why do traces of the "Simian Shelf" exist in certain races??

Answer 1

I read an article about that recently.  It stated that the only race where these traces are found is the Negroids.  My guess would be that it's due to their being a few rungs lower on the evolutionary ladder.

Answer 2

Neanderthal had this in the Jaw area & since we have recently (last year) discovered an "introgressed gene" that happened in the ME 37,000 years ago & spread to 70% of H.Sapiens since; I expect to find that among Europeans or other groups that migrated out of Africa through the ME.  Europeans had the most prolonged contact with Neanderthal & I expect them to have more unidentified genes associated with Neanderthal.

Anthropologists quickly grabbed on to the analysis of MtDNA  some years back to conclude (prematurely) that Neanderthal contributed nothing to the H.Sapien gene pool. This is probably incorrect, but a completely sequenced Neanderthal genome is expected within the next 3 yrs.

Answer 3

Ummm... because their more closely related to simians???