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.
Marginality and animal genetic resources
The conventional wisdom is that landraces and local breeds are better adapted to marginal conditions than modern crop varieties and livestock breeds. A paper has just been published in Agricultural Systems that tries to quantify this. The researchers defined marginal areas “as those areas where possible land uses are relatively limited because of higher altitude, shorter growing season, steeper slopes, less fertile soils or broadly speaking because of generally lower soil productivity.” They calculated a synthetic index of marginality using all kinds of environmental and socio-economic data and mapped its value throughout Europe. They also mapped the distribution of goat and sheep breeds using data from the Econogene project. Then they calculated how good the marginality index was at predicting the presence of local breeds. The result: “Increasing marginality, as measured by these indices, is positively and significantly correlated to the fact that local, traditional breeds are present.”
Re-wilding Europe
There was much talk a couple of years back about re-wilding – a suggestion to establish a plausible facsimile of the Pleistocene fauna of North America by introducing carnivore and herbivore species (including wild relatives of livestock) from Africa and elsewhere to the Great Plains. ((Check out a recent interview with a proponent. There’s even a Rewilding Institute now.)) But perhaps Europe might be a better candidate for this kind of thing.
Where the rubber hits the road
The rubber tree comes from Brazil, but natural rubber itself mostly comes from SE Asia plantations these days. One of reasons is the leaf blight fungus, but now comes news of resistant varieties. This may herald a resurgence in climate-friendly natural rubber at the expense of the synthetic kind, which is made from oil. But will that positive effect be negated by increased cutting down of the rainforest to establish new plantations in Brazil?