A long article in icWales, the self-described “national website of Wales,” details the predicament of the local pony breed. Once an important part of everyday rural life – and indeed industrial life, due to their use in coal mines – more recently a children’s trekking pony, there is now limited demand for the breed. Wild herds have thus declined dramatically, no doubt resulting in genetic erosion. Does it matter? A resounding yes echoes around the hills.
Smorgasbord: take what you need
Like a perfectly assembled buffet, everyone should be able to find something nourishing in Fidel Castro’s latest essay: Where Have All the Bees Gone? And Other Reflections on the Internationalization of Genocide ((Actually, I don’t know whether that is the title he gave it himself, but it’ll do)). Ranging across more topics than you can shake a stick at, he says a couple of things that I happen to agree need saying. Like criticising the modern mania for biofuels: it’s a sick joke in developed countries. As The Economist said two weeks ago, “It is not often that this newspaper finds itself in agreement with Fidel Castro, Cuba’s tottering Communist dictator. But …” ((In fairness, they were commenting on an earlier essay by Castro, but one that contained the same points))
(Disparities between Cuba’s infant mortality rate and medical services and those of the United States are not the subject of this blog.)
Then there are the bees. Here’s Fidel:
Scientists are entertaining all kinds of hypotheses, including the theory that a pesticide may have caused the bees’ neurological damage and altered their sense of orientation. Others lay the blame on the drought and even mobile phone waves, but, what’s certain is that no one knows exactly what has unleashed this syndrome.
There’s enough trickiness around without going into the mobile phone argument. I’d be happy to be proved wrong on this, but for now I’m not even prepared to link to the many, many outpourings on the subject. Let’s just say that mobile phones are the least of Cuba’s worries, with the lowest penetration of any country in South America.
Oekologie
The latest edition of a relatively new blog carnival called Oekologie — very groovy — is up at Behavioral Ecology Blog. There’s not an awful lot of direct agricultural interest. A post from GrrrlScientist summarizes a study on the evolution of Soay sheep on the island of Hirta in the Outer Hebrides (not) near Scotland. Cold winters select larger sheep, which selects for fewer sheep. But not all winters are that cold. On the indirect front, there are an awful lot of posts on climate change, including the one from our own Andy Jarvis, which Oekologie compiler Matt admits he found “too depressing … to read”. Shame on you Matt, but thanks for the carnival.
Lactose tolerance: independent origins and strong selective pressure
Michael Kubisch has submitted another post, based on an article in Nature Genetics. Unfortunately the full article and a News and Views piece about it are behind a paywall. However, I’ve done some sleuthing to find a few links that give more details on the story, which I’ve added at the end. As Michael noted, the article is “not about genetic diversity of agricultural species, but how agriculture has affected human genetic diversity”. That’s good enough for us.
The ability to digest lactose, one of the primary carbohydrates in milk, varies widely among adult human populations. In some European countries nearly 90% of individuals can tolerate lactose, while the incidence in some Asian countries is as low as 1%. The inability to digest lactose is caused by a decline in lactase, the enzyme that breaks down lactose into sugars that can be absorbed into the blood stream. This decline starts shortly after weaning and most likely reflects the fact that until animals were domesticated, milk was simply not a staple of human diets. Lactose tolerance, or lactase persistence as it is sometimes called, in turn is facilitated by a continuous production of lactase throughout adulthood. Not surprisingly, lactase persistence appears to be closely linked to whether a population has traditionally practiced a pastoral or an agricultural lifestyle.
This new study examined the incidence of lactase persistence in several African populations. Based on analysis of genetic markers the authors of the study conclude that the trait appears to have evolved not only independently from Europe, but also more than once in Africa itself. Given that the prevalence of the trait is so high in some populations and domestication of milk-producing animals only goes back 12000 years or so, which is a mere blink of an eye in evolutionary times, milk consumption must have provided a significant benefit for human survival.
Those links:
- New York Times: Lactose Tolerance in East Africa Points to Recent Evolution
- Genetic Archaeology.com: Lactose tolerance gene proves Natural Selection in humans
- University of Maryland press release: UMd-Led Team Discovers Gene Mutation for Milk Tolerance in Africans
- Understanding Evolution ((Best of the lot, by far. What a fine site.)): Got lactase?
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Chinese fungi and tea
I’m killing a few hours at Hong Kong International Airport, so I pick up the latest issue of China Today. There’s a number of really interesting articles, but two little snippets jumped out at me. The first is a short note on the Chinese Caterpillar Fungus, Cordyceps sinensis. No, I’d never heard of it either, but it turns out that it is important in Chinese traditional medicine, and that it has not been possible to grow it in the lab. Until just now that is, hence the note in the Sci-tech Info section announcing the possibility of mass-production.
The other really nifty piece of sino-information occurs in the opening section of an Around China piece on the Zhenyuan Yi-Hani-Lanu Autonomous County. It seems that this ancient tea-growing area, with its tea-dominated forests, boasts what is considered the oldest and largest tea plant in the world. At 25 metres tall, almost 3 metres in diameter and an alleged 2,700 years of age, it is apparently quite the tourist attraction, and “its fleshy, glossy leaves produce a strong and lasting flavour.”