Republished from w t Sanger institute

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Branch lengths are drawn proportional to the estimated times between successive splits, with the most ancient division occurring ~190 kya. Colored triangles represent the major clades, and the width of each base is proportional to one….

largest ever study of global genetic variation in the human Y chromosome has uncovered the hidden history of men. Research published today in Nature Genetics reveals explosions in male population numbers in five continents, occurring at times between 55 thousand and four thousand years ago.

The study, led by Dr Chris Tyler-Smith of the Wellcome Trust Sanger Institute, analysed sequence differences between the Y chromosomes of more than 1200 men from 26 populations around the world using data generated by the 1000 Genomes Project.

The work involved 42 scientists from four continents.

 

“We identified more than 60,000 positions where one DNA letter was replaced by another in a man with modern descendants, and we discovered thousands of more complex DNA variants. These data constitute a rich and publicly available resource for further genealogical, historical and forensic studies.”

Dr David Poznik, from Stanford University, California, first author on the paper

Analysing the Y chromosomes of modern men can tell us about the lives of our ancestors. The Y chromosome is only passed from father to son and so is wholly linked to male characteristics and behaviours. The team used the data to build a tree of these 1200 Y chromosomes; it shows how they are all related to one another. As expected, they all descend from a single man who lived approximately 190,000 years ago.

The most intriguing and novel finding was that some parts of the tree were more like a bush than a tree, with many branches originating at the same point.

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