When the chimpanzee genome was published a couple of years ago we got a fascinating insight into how similar we are to our closest relative. But, when scientists found genes that differed only slightly between humans and chimpanzee it raised the mystery of who had the original and who had the mutation. Until now.

 The way through this impasse is to compare chimpanzees and humans to a third species–ideally another primate. But it was not until today that scientists had a third primate genome to study. Now they have all the DNA from a macaque.

I happen to be re-reading Dawkin’s The Ancestor’s Tale at the moment so I know that we split from our chimpanzee cousins about 5 or 6 million years ago and that we apes split from the monkeys about 25 million years ago. That’s why I found this so fascinating…

Some people carry versions of genes (known as alleles) that either cause diseases or predispose them to getting sick. When scientists studied the chimpanzee genome, they discovered that chimpanzees carry the human disease allele, without suffering the human disease. The macaque genome team expanded this search, looking for matches in chimp and macaque genomes to every known human disease allele. They discovered 229 cases in which the disease allele turns out to be the ancestral version.

There have been a bunch of papers published recently about the macaque genome and its differences from ours. Whenever papers like this are published you can always read a paragraph about it in The Economist or Time or maybe even a whole article in The New York Times. But the best place by far is The Loom by Carl Zimmer. Go read it now.
About 9 months ago, I subscribed to about 30 science blogs but, one by one, I dropped them. The Loom is one of only two science blogs that I still read regularly and it’s always good.