Genome sequence of 4000 year old human
Scientists have decoded the genome sequence of an ancient human who lived 4000 years ago using hair samples recovered from the permafrost at an archaeological site in Greenland.
The DNA code reveals that the individual was male, had brown eyes, wiry black hair, dark skin, short stature, dry earwax and a tendency to baldness!
The work, published in Nature and carried out by University of Copenhagen researcher Eske Willerslev and his colleagues, reveals some intriguing details about how humans got to be in that part of the world and when.
The brought the man's characteristics to life by analysing the ancient DNA for sequences called SNPs (single nucleotide polymorphisms), which are like genetic signposts pointing to the presence of certain appearance traits.
By comparing the SNP pattern from the ancient man with SNPs carried by present-day populations known to have certain characteristics, it was possible to discover what this person would have looked like and where on Earth he and his tribe arose.
Most existing theories suggested that the Saqqaq people, to whom this man belonged, were migrants from neighbouring native American or Inuit populations. Instead, what the analysis shows is that this ancient eskimo is related to neither; he was actually from somewhere in Siberia.
This suggests that there must have been a significant, and much more recent, migration from Siberia across the Bering Strait, over North America and into Greenland about 5000 years ago.
Understanding how humans evolved and populated the globe by which routes and over what times is an open book; this new study shows that when the power of modern genetics is brought to bear upon the problem great leaps forward in our understanding are possible.