Ancient Andean agriculture

Meanwhile, on the Western slopes of the Andes, at about the same time as their cousins half a world away were domesticating the cat — which is a lot earlier than has been thought — people in what is now northern Peru were growing peanuts, squash and cotton. That’s according to well-dated macrofossils, as reported in a paper co-authored by our friend and peanut expert David Williams, and picked up in the mainstream press.

We’ve blogged before about recent work that is pushing back the date of agriculture in the New World. There’s a great review of the latest thinking on the “roots of agriculture,” including in the Americas, in the latest Science, but you’ll need a subscription to read it, unfortunately. Anyway, to summarize heroically the new consensus arising from collaboration among geneticists and archaeologists, it seems the process of crop domestication probably took much longer than previously imagined, thousands rather than hundreds of years. And that it may have started at about the same time in different parts of the world, perhaps as a result of changes in climate (and levels of carbon dioxide in the atmosphere).

How the cat became a pet

A DNA study of almost a thousand wild and domestic cats from around the world is helping to unravel the evolutionary history of this most numerous of household pets. There are five wild subspecies of nearest-relatives, including one in the Near East, from which all domesticated cats are derived, though there has been subsequent hybridization of house cats with local wild populations here and there. Modern cat breeds can trace their origin to at least five mothers domesticated in the Fertile Crescent around the same time as agriculture started, over 9,000 years ago. And, coincidentally, there’s news also today of archaeological evidence from nearby Cyprus backing up that date.

Climate change and agriculture

A press release from the Smithsonian Institute draws attention to a study that links climate change, culture and agriculture. Mexico’s Central Balsas Valley is believed to be one of the sites where farmers domesticated maize and squashes. The new data suggest that the climate in the valley became cooler and drier at the end of the most recent ice age. Lakes in the valley formed at around that time and became magnets for human settlements, which contain evidence of maize and squash pollen. Of course, we’re not saying that climate change is always a good thing …

Pollo y kumara

Chickens crossed to South America from Polynesia, while sweet potatoes went the other way, who knows, maybe in the same canoes. Ok, let’s unpack that a little bit. A DNA study has found links between 14th century (i.e. pre-Columbian) chicken bones buried on the coast of south central Chile and chicken bones from Polynesian archaeological sites, particularly on Tonga and American Samoa. Meanwhile, ocean circulation models suggest that, contrary to previous thinking, a ship setting off from various points along the western coast of South America could indeed have delivered sweet potato seed pods (and bottle gourds?) to Polynesia (in particular the Marquesas) in a relatively short period. These studies have been all over the news lately and are being much discussed in the blogosphere. For example, Gene Expression and John Hawks work through some of the anthropological questions.

Ancient genebank dug up?

Is it possible to trace an intellectual connection from Roman horti to the medieval and renaissance physic garden to colonial botanic gardens such as Kew to the modern genebank? Possibly. If so, news of an archaeological discovery not far from where I’m sitting will be of importance to all who take an interest in agricultural biodiversity.