Nibbles: Rhubarb and the EU, Mexican biodiversity Qat in Yemen, Organic cubed

How did farming start?

No answers: we just don’t know. But Bruce Smith, whose book on The Emergence of Agriculture remains one of the best, recently told an audience at Harvard University that although most people see domestication as “a before-and-after kind of event, with hunter-gatherers before and farmers afterward. The reality … was likely far more complex.”

Hard to argue with that, especially in light of increasing evidence that people were both altering the environment to favour wild food sources and cultivating plants without domesticating them. Smith talked a bit about which plants were domesticated — “early-succession species that did well in disturbed environments that humans could create for them” — but not, at least according to the reports, about whether there’s any scope for additional domestications. We’ve asked before: are there any species that people should be cultivating, and possibly domesticating, now that they have so far ignored? My own contenders would be perennial grains. The plants are there; they just need a few thousands year’s work.

Smith’s lecture was part of a series called Food for Thought. ((Harvard brains hard at work.)) We missed one by my old mucker Richard Wrangham, of How Cooking Made Us Human, but tomorrow, 23 February, Samuel Myers will “discuss troubling trends, including climate change and increased threats from pests and pathogens that may constrain the world’s resources, requiring new approaches to sustainable agriculture.” I wonder whether agricultural biodiversity will feature. Someone go, and tell us.

Nibbles: Sequencing, Agricultural origins, Mating systems, Tomato shelf-life, Beer vs Tea, Soy, Carrot, Seed processing, Screw-pine, Yams, Salicornia, Pollinators

Cracking the code of dog diversity

Another contribution from Michael Kubisch.

Ever wondered why your rat terrier looks so different from your neighbor’s mastiff? Well, eons of selective breeding, of course, which have resulted in genetic differences between these two and other dog breeds. Man’s best friend was undoubtedly among the very first animals to be domesticated, although the huge variety of breeds found today is probably a much more recent phenomenon. Which part of the dog genome, or more pertinently which genes, were involved in generating this diversity remains largely a mystery — but one that many geneticists would like to solve.

A first glimpse has now been provided by a group of scientists who compared genomic data from dogs belonging to ten different breeds using what is called single-nucleotide polymorphisms or SNPs for short. SNPS are very helpful because the presence of a particular SNP sometimes is indicative of the presence of a specific allele at a nearby gene. Similarly, if there are SNPs that differ between two dog breeds it is possible that nearby genes may be different as well and that those genes may have played a role in what sets these breeds apart.

The study revealed 150 areas of the dog genome containing more than 1000 candidate genes that appeared highly variable between those breeds that were examined. Not surprisingly perhaps, several of these genes are known to determine things like coat color, size, skeletal morphology and behavior. However, interestingly, several candidates included genes that are known to act as regulators of other genes, suggesting that some evolutionary changes are not the result of variant alleles of genes but changes in how these genes are controlled. More interesting insights are sure to follow.