A study of Y chromosomes showed that the male population exploded some 50,000 years ago.
More specifically, the study revealed indicators in the Y chromosomes that led to significant increases in males across five continents - a finding that may be linked to human development.
The study is the biggest of its kind, showing genetic differences in human Y chromosomes from all across the world, revealing the undiscovered history of men.
The Y Chromosome
Study first investigator David Poznik says Y chromosome of present-day men may give information about how their predecessors lived their lives.
The said chromosome is solely transferred from the father to the son hence, it is entirely connected to male behaviors and features.
The research team created a tree of 1,200 Y chromosomes and was able to present that all them were linked to each other. Turns out, they all came from one man who walked the Earth about 190,000 years ago.
The Explosion Of Men
Poznik says the team was able to determine over 60,000 positions where one DNA letter was replaced by another in a human with modern brood. Aside from that, they discovered more complicated DNA variants, spanning thousands. Such findings may help build a rich and widely available data for additional related researches.
The team was able to come up with numerous discoveries, but the most striking of all is the fact that some areas of the generated tree looked more like a bush with multiple branches coming in from the same origin.
"This pattern tells us that there was an explosive increase in the number of men carrying a certain type of Y chromosome, within just a few generations," says lead study author Yali Xue from Wellcome Trust Sanger Institute. She adds that the team was only able to detect this in males and in limited groups.
The earliest explosion of male population dates back to 50,000 to 55,000 years ago in Europe and Asia. This was followed by the rise of men in the Americas 15,000 years ago. Latter explosions were noted in South and East Asia, Western Europe and sub-Saharan Africa some 4,000 to 8,000 years ago.
The earliest expansions were said to be a result of colonizations by modern humans, while the latter reports are more ambiguous.
Corresponding author Chris Tyler-Smith says the best interpretation for the expansion is the progress in technology that may be regulated by small numbers of men. Examples of this include metal working, wheeled transport and coordinated armed conflicts, which may now be studied further.
The study was published in Nature Genetics on April 25.
