- BBC slideshow on the wild apples of Khazakhstan.
- Malawi breeder decries genetic erosion.
- Bananas good for food security in central Africa. Well, yes.
- The ruminant family tree deconstructed.
- Public to help researchers locate wild honeybee colonies in Hawaii.
- “No Pesticides No Foreign Drinks.”
Revisiting domestication
One of the crucial pieces of evidence in studies of cereal crop domestication is the DNA mutation that keeps seeds attached to their stalk. ((Discussion can be a bit convoluted, because the process of separation is usually called shattering, and the crucial mutation is therefor an anti-shattering allele, but most people talk about it as the shattering gene, or shattering allele. The key point is that domesticated crops do not shatter.)) Staying attached — not shattering — is important because it allows people to harvest the seeds much more easily. You can gather bundles out in the field, carry them back to the village and do the processing there. If the seeds shatter, you have to harvest early, before they are fully ripe, and thus risk not getting their full food value or do all the processing out in the field or else risk losing much of the harvest on the way back to the village.
The loss of shattering is thus a crucial step in the process from cultivation to domestication.
The shattering mutation itself is extremely rare. In rice, for example, all types of rice share essentially the exact same mutation, crucial evidence that in rice it occurred only once, and then spread from Japonica types back into the wild and from them into the Indica types, domesticated a little later.
Now, we (and others) occasionally play the game of why aren’t any new species being domesticated. Sometimes the answer is that too many people are too satisfied with the few crop species that support humanity. Other times, it is that it is just too hard or too time-consuming, especially if one is hanging around waiting for a non-shattering mutation to arise. Mostly, both.
But hey! We know the gene that is mutated in domesticated rice, and wheat, and sorghum, and maize, and other species too, probably. And we know the nature of the mutation. And we know that the more we know, the easier it is to find out about new species. So, what if some smartypants isolated the gene from an as-yet-undomesticated species, say Coix , mutated it so it no longer functioned to shatter the seeds, and stuck it back in? ((It is important to do it within the species’ own DNA, thus avoiding accusations of God-like meddling.)) Then just give loads of samples to loads of farmers and let them get on with the business of selection.
Could we engineer a post-cambrian explosion of crop diversity?
Nibbles: Preservation, Markets, Cuy, Fallows in slash-and-burn, Rice
- Pickling everything. Japanese edition.
- Mapping farmers’ markets in the US. Idaho has zero demand for organic produce?
- Domesticating the guinea pig. Cute AND good to eat.
- Longer fallows mean more diverse soil microinvertebrates, better soils in French Guiana.
- Archaeological remains of rice from China.
Nibbles: Goats in Europe, Horse domestication, Food map, IITA training, Asian collaboration, Tom Wagner, Tomatoes
- First Law of Geography valid after all.
- Multiple domestication of the horse in China.
- The Atlantic has a weird food map. What does it mean? Answers on a postcard, please.
- IITA tells farmers about its core collections, among other things.
- Bhutan and Thailand collaborate on agrobiodiversity conservation.
- Details of Tom Wagner’s European Tour. He’s the amateur breeders’ breeder.
- Tomatoes thrive on urine diet. Not a piss-take.
Dog fight over canine origins
We’ve pointed briefly to recent studies on the origins of the domestic dog, where two schools of thought hold sway. The conventional version offers east Asia — China, more or less — as the centre of dog diversity and, by implication, the place where dogs were first domesticated. An apostate view is that dogs were domesticated in Africa and perhaps in Europe too.
There’s no clear resolution in sight yet, but it looks as if the Chinese dog may be on top. A news report in Science gives details of (and links to) a new and more detailed study from Peter Savolainen and his team:
The data reaffirm a single site for domestication and pinpoint the origin of the domesticated dog to a region south of the Yangtze River, where wolf taming was quite common, Savolainen’s team reports today in Molecular Biology and Evolution. That’s where the largest number of similar groupings of DNA, called haplogroups, is found. As the researchers looked at dogs farther from this region, they saw fewer haplogroups; Europe had only four, for example. “The gene pool we are finding in Europe and Africa are a subset of the South Chinese gene pool,” says Savolainen.
But the African dogs aren’t rolling over yet.
Carles Vilà of the Biology Station of Doñana-CSIC in Seville, Spain … points out that other genetic studies suggest dogs date back at least 20,000 years and that archaeological remains of dogs in Europe are almost as old. … “I’m not convinced by the results,” he says, “and I do not think this is the last that we will hear about the time and place of the domestication of dogs.”
That seems certain. Back in the days before DNA a multiple-origins theory was all the rage, but then, it was for H. sapiens too.