Putting the Y into you
What the Y chromosome tells us about our past
The male Y chromosome contains more DNA than the mitochondrion, which is passed on down the female line. It carries more than 59 million base pairs – compared with 16,000 in a mitochondrion. That difference provides greater scope for variation, meaning it is more useful for detailed analysis of how DNA markers have been carried down the generations. Such analysis can even shed light on aspects of individual ancestry, as well as tracking population movements.
As many countries share our custom of passing surnames from father to son, DNA results can be compared with old-fashioned genealogies and used to see whether two people with the same surname are genetically related. More remarkably, DNA profiles from crime scenes might be useful in predicting the possible surnames of men who were there.
A team led by Professor Mark Jobling at the University of Leicester has tested how useful this technique could be and whether it might raise unjustified suspicions. The researchers say it could help generate a list of the more likely suspects, but it couldn’t be used to provide solid evidence.
Another type of analysis of the Y chromosome can tell men where their ancestors came from based on a set of distinct markers on the chromosome. This sort of work is drawing new maps of countries, such as the UK, which have experienced repeated waves of migration. It has shown, for example, how Viking place names and the surnames derived from them in parts of northern England go along with Viking-descended Y chromosomes.Lead image:
Steve Evans/Flickr CC BY NC ND