More recent advancements in technology seem to be causing the population to decline.
The rapid expansion of males in the 55,000 to 50,000 year range probably represents a bettering of conditions after the severe cold and starvation that shrank the human population when the Toba supervolcano blew its top. This eruption left a crater 18 miles by 65 miles—larger than the Yellowstone basin—and a noticeable slump in the earth’s temperature record around 74,000 years ago.