Fiber, not food, the reason for agriculture?
Linking archaeology and agrobiodiversity
It was probably a silly thing to say. A couple of days ago I briefly mentioned the models that researchers have built, based on present-day genetic data on Europeans, to understand the rate and pattern of human movement into the continent during the Neolithic. And I made the throw-away comment that I wasn’t aware of similar models for crops. I sort of instantly regretted it, and last night did some googling.
At first I thought perhaps I was right after all. I found a recent (2006) paper whose abstract says:
Thus far, no attempts have been made to track the movement of the founder genetic stocks of the first crop plants from their core area based on the genetic structure of living plants.
Further on, though, the authors say they’ve done just that for wheat. And I also found reference to a “Domestication of Europe” project which sought
to determine the extent to which phylogeographical analysis of modern landraces of barley and wheat, combined with examination of ancient DNA in preserved specimens, can reveal genetic information pertaining to the spread and establishment of cereal cultivation from its points of origin in Southwest Asia into and through Europe.
I think the project must have run from 2003-2006. The Glyn Daniel Laboratory for Archaeogenetics at Cambridge was one of the labs involved, and some of the work, and other related research projects, is described on its website.
So there are people out there trying to link up the archaeology and human genetics of agricultural spread in Europe with the genetics of crops and livestock. Is it too early for a Grand Synthesis?
The spread of agriculture into Europe
You may recall a post a few days back on how domestic pig keeping spread into Europe. Well, Razib over at Gene Expression, a genetics blog, has a post today which includes a map of the spread of agriculture north and west from the Middle East. He points out that current thinking is that either the practice of agriculture did the spreading (cultural diffusion), or people themselves (demic diffusion) — or both. Both was what the pig work implied, of course. Human genetic studies suggest that Neolithic people have made a fairly low (maybe 20%) contribution to European ancestry, and Razib summarizes the current debate about whether that therefore refutes the hypothesis that movement of people was involved in the spread of agriculture, as well as that of ideas. Bottom line: it probably doesn’t.
He also links to a recent paper that calculates a figure for the rate of movement ((Tracing the Origin and Spread of Agriculture in Europe. Pinhasi R, Fort J, Ammerman AJ. 2005. PLoS Biology Vol. 3, No. 12. doi:10.1371/journal.pbio.0030410)): 1 km/year, give or take. That was arrived at by interpolating radiocarbon dates of Neolithic archaeological sites across Europe, and it fits very well with the results of models using human genetic data. ((As far as I’m aware, however, nobody’s done anything similar with crops.)) An interesting way to think about that speed of movement is that it is roughly a one-day walk per generation.
Natura morta
From EurekAlert: “The American Society for Horticultural Science has published multimedia podcast files of 98 horticulture presentations from the 2007 Annual Conference in Scottsdale, Ariz.” Check out, in particular, James Nienhuis of the University of Wisconsin, Dept. of Horticulture, talking about Renaissance art and agrobiodiversity, more specifically vegetable domestication. Wonderful stuff.
International meet on agrobiodiversity
UC Davis is organizing a follow-up to the international symposium held in Aleppo, Syria in 1997 under the name of “The Origins of Agriculture and the Domestication of Crop Plants in the Near East.” Also dedicated to Jack R. Harlan (1917–1998), celebrated agricultural botanist and plant explorer, the 2008 conference is entitled “Biodiversity in Agriculture: Domestication, Evolution, & Sustainability.” If you’re planning to go, how about reporting on the conference for our readers at Agricultural Biodiversity Weblog?