A DNA study suggests that small dogs started to appear about 10,000 years ago as a result of a mutation in a single gene (called IGF-1). I wonder if something similar will be found in other domestic animals.
Domestication
Michael’s post on water buffalo genetic diversity and domestication reminded me that I was intending to point you all in the direction of Dienekes’ Anthropology Blog. Although Dienekes mainly blogs about the genetic diversity and evolution of humans, he does occasionally link to papers on animal domestication and related issues. He has an RSS feed, which makes it easy to monitor his blog. In the past couple of years he has pointed to interesting papers on:
Incidentally, a great paper reviewing the use of genetics and archaeology to document domestication came out last year and you can see the abstract here. Now, what’s really needed is for someone to bring together the human, livestock and crop genetic data.
A new route for pigs and people across the Pacific
The standard story of Pacific colonization is that people and their crops and livestock spread across it in a generally southwestern direction. Scientists from Durham University and the University of Oxford are renavigating the details. They looked at DNA from various pigs across the Pacific, and conclude that their journey may have started in what is now Vietnam. It has always been assumed that the people and their agriculture traveled together as a single package. This research indicates that different parts of the package took different routes.
There’s more detail at a Durham web site about pig domestication, but the actual paper does not seem to be available online yet. Here’s the press release announcing it.
Audible Darwin
It is easy to forget sometimes that The Origin of Species actually starts with a lengthy discussion of genetic diversity in crops, ornamentals, livestock and pets, although of course Darwin doesn’t call it that. He calls it “variation under domestication,” and you can now hear his seminal words, by downloading 24 hours’ worth of audio files from here. There’s a also a link to an e-text of the book.
Very diverse barley discovered … and already under threat?
SciDev.net reports on a paper in Theoretical and Applied Genetics that identifies the world’s most genetically diverse barley varieties. SciDev.net and other press reports focus on the high diversity of the barleys, found growing in farmers’ fields around the captial city of Asmara in Eritrea, as a source of potentially valuable material for improving tropical varieties worldwide. They point out, too, that the populations are threatened by urban development and that Eritrea has no genebank in which to protect them. But does Eritrea really need its own genebank, or have they more pressing priorities? A researcher from ICARDA, which has a perfectly serviceable genebank, was on the team. The International Treaty on Plant Genetic Resources for Food and Agriculture guarantees free access to the material if stored there. Eritrea was one of the first signatories of the Treaty. What’s the problem?
More interesting, perhaps, is a part of the paper that the reports I read neglected to mention. The molecular analysis indicates that the Horn of Africa may be where barley was first domesticated. That honour usually goes to the Fertile Crescent, with the Horn a “secondary centre of diversity”. But Eritrean and Ethiopian barley may actually have been domesticated independently.