Was sunflower domesticated in Mexico or what?

I don’t know much about sunflower. That’s obvious enough from the cavalier fashion in which a recent Nibble of mine referred to a press release on a PNAS paper on sunflower domestication by David Lentz and others. 1 Briefly, that paper presented a range of archaeological, linguistic, ethnographic and ethnohistoric evidence for the domestication of sunflower in Mexico by 2600 BC. This would complement a separate, independent, well-attested domestication in the Mississippi Valley. That’s important not only academically but also for the insights it would give into genetic structure within the species, and hence possible breeding strategies.

But it looks like I unwittingly walked into a bit of a controversy. It seems things are a bit more complex than the press release made out. In a 2007 short communication in GRACE, the great Charles Heiser reverses himself with regards to some archaeobotanical material he had previously identified as a sunflower achene and as a result comes out against the Mexican domestication for the crop first advocated by Lentz in 2001. The available molecular evidence seems to support Heiser.

I don’t know much about sunflower. But after today, I know a little bit more. And I’ll be keeping an eye on this academic spat to learn more.

Maize in Africa

An article in the latest Economist discusses the Malawi fertilizer subsidy programme. There’s been a fair amount in the media about this lately, and in particular about whether the bumper maize harvests of the past couple of years can be attributed to the extra fertilizer 2 now finding its way onto farmers’ fields increasingly sown to modern varieties, or just to better rains. I think the jury is still out on that one, but check out this statement from the piece in The Economist:

…local seed varieties, little altered from those first brought by the Portuguese centuries ago…

I don’t know about you, but I think that rather underestimates the power of natural selection, drift and recombination. Not to mention 500 growing seasons’ worth of painstaking selection by twenty generations of African farmers.