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.
Michael Kubisch is a geneticist and reproductive physiologist working at the Tulane National Primate Research Center in the New Orleans area. He’s sent us his take on a recent paper on the genetics of the water buffalo. We really welcome this kind of contribution from our readers. Keep ’em coming! Here’s what Michael has to say:
Results of an interesting study by Chinese researchers have just been published, describing an extensive analysis of the genetics of Chinese swamp water buffalo (Bubalus bubalis). The Chinese swamp-type buffalo differs from the Indian river-type buffalo by the fact that it has 48 chromosomes compared to the 50 found in the latter. There is a third subspecies, the wild water buffalo, which may still exist in Southeast Asia, although its population size and genetic status are unknown and the animal is listed on the IUCN red list as being threatened. Based on analysis of mitochondrial DNA (which is solely inherited from one’s mother and consequently ideal for tracing maternal inheritance patterns), it appears that river and swamp buffalo split about 28,000 years ago with a further split in the swamp buffalo into two maternal lines taking place about 18,000 years ago. The genetic diversity varies between the two swamp buffalo matrilines in China and the authors suggest that the difference between the two lines might in part be due to the fact that occasional genetic introgression from wild swamp buffalo might have taken place into one of the lines. Interestingly, domestication of water buffalo seems to have occurred independently in India and China, most likely as a result of rice cultivation. Substantial numbers of water buffalo outside exist Asia, among other countries in Italy, where, as any cheese afficionado will know, their milk is used for the production of mozzarella.
Thought that would get your attention. Actually, what the research summarized here revealed was that a couple of genes mutated independently thousands of years ago in the ancestor of the modern grapevine, whose berries were red. The resulting white variety proved to be the ancestor of almost all of the 3000 or so white grape varieties we have today. This discovery from CSIRO will apparently be useful in marker-assisted breeding.
I’ve gone back to my blog a few days back on crop wild relatives and expanded it somewhat. In particular, I’ve added links to several more recent papers on the subject. Should have probably done that in the first place. Sorry.
A couple of papers discussed here and here (among other places: the chili pepper story in particular has been getting a lot of media coverage) describe how the minute, species-characteristic starch grains found in micro-crevices on stone tools and cooking utensils recovered from archaelogical sites are being used to study the domestication of crops as varied as maize, cassava and chilies in the Americas. The findings are pushing back the timing of domestication and suggesting that wet lowland areas were more important in the process than previously thought. Jeremy blogs on the chili angle at greater length here. No word on the past of cactus cultivation, at least in these papers, but this piece suggests its future may be troubled.