How quickly?
This is the last paragraph of the paper, a section called “Final Remark”:
The somewhat similar inferred rs4988235-A allele frequencies between the early Middle Ages and today at different locations does not exclude the possibility of ongoing selection during that period, because this likely represents the transitional phase of the sigmoid frequency trajectory expected for a dominant allele. For LP, it now seems likely that the phase of most rapid frequency rise was between 4,000 BP and 1,500 BP. We contend that research should be focused on this phase to bettehr understand the evolutionary history of the most strongly selected single gene trait in Holocene Western Eurasia and many other parts of the world.
That’s YEC time scale quick 
Yes. Ken Ham will milk it for all its worth.
Pull the other one, it’s got bells on it!
He will, for butter or worse!
These puns. Oh dear. Oh dairy me.
The puns are udderly maddening.
This Discourse platform would be greatly improved by addition of a punster badge, and/or by the addition of auto-banning for the posting of bad puns.
We can create and manually award badges…
. . . for the enjoyment of pun and all.
There are good puns? 
Badges? We ain’t got no badges. We don’t need no stinkin’ badges. Vamanos!
You all should be PUNished, lol.
Really bad puns led to the three Punic Wars between Carthage and Rome (264 BCE to146 BCE.) That barbaric conflict also introduced the very first “Your mama …” jokes.
There’s no limit to human suffering.
Oh, the infamous Pun-ic wars.
Study reveals lactose tolerance happened quickly
I had an uncle who suffered from severe frostbite in the Battle of the Chosin Reservoir during the Korean War. He lost all ten toes from the sub-zero temperatures. (It got down to -36 degrees F.) As a result, my aunt complained that his feet looked “totally gross”, and she would not let him go barefooted around the house during the summer.
My uncle always said that she was lack-toes intolerant.
POSTSCRIPT: This part is totally true: many years later the survivors of that battle had problems with the Veterans Administration denying claims for the severe medical complications arising late in their senior years from undocumented frostbite injuries. So the veterans formed a lobbying group called “The Chosin Few.”