I asked my masters in the Freethoughtblogs collective, because there are (I believe) some evolutionary biologists in the house. However, I don’t want to turn this into a case study of “what happens when you ask a scientist a question?” [because the answer is usually “maybe” or “that’s bullshit.”]
Over at Vice, there is a report that some elephants have evolved to be tuskless, due to the evolutionary pressure caused by poachers/hunters. [vice]
Elephants in Mozambique are evolving away from having tusks due to pressure from rampant poaching over decades, according to a daunting new study.
Published in the journal Science on Friday, the report from researchers across departments at Princeton University, the non-profit ElephantVoices, Gorongosa National Park in Mozambique, and the University of Idaho, analyzed survey data that suggests natural selection has favored tusklessness in female elephants – a rare genetic trait that has become more common – amid high rates of poaching and population decline.
I always thought that evolutionary changes are slow(ish) and elephants haven’t really been hunted to near-extinction prior to the 1800s. (Probably a combination of cheaper/faster travel and the development of massive empires with a wealthy class that can afford to travel someplace for their bloodbaths) – so I asked the FtB HiveMind(tm) and I got a kind of “well… maybe.” One thing I hadn’t thought of is that the population of elephants in some areas are very small, which amounts to an “evolutionary bottleneck” – changes ripple through small populations faster. So, it could be.
The researchers took scans of the entire elephant genome and located two genes associated with tooth development in mammals, both of which guide the formation of enamel, dentin, and other materials necessary for tooth and tusk development. One of the genes – AMELX, which provides instructions for the creation of a protein called amelogenin – was found to be associated with selection pressure due to poaching.
The team undertook the study after observing both growing rates of tusklessness among female elephants and severe population declines (2,542 elephants in 1972 whittled down to 242 in 2000) among both sexes in Gorongosa National Park. A civil war in Mozambique from 1977 to 1992 killed off some 90 percent of the country’s elephant population, the paper notes, as armies on both sides of conflict targeted the animals for ivory. Though tusklessness is currently considered a rare genetic trait in female African elephants, they’re significantly less attractive to poachers. Tuskless elephants are therefore much more likely to survive, passing on the tuskless gene to their offspring, who pass it onto their offspring, and so on. The paper notes that as the population of elephants took a nosedive, there was a threefold increase in the frequency of tuskless females.
242 elephants is a tiny population; that’s a hell of a bottleneck. Apparently early proto-humans experienced a similar bottleneck, in which it came down to 6 females that everyone alive today descended from.
I’m not too encouraged for the fate of the elephants, though. As we’ve seen from NRA executives, basically nothing is safe from the “killing as entertainment” crowd; the elephants are going to have to evolve to not have feet, next, so Wayne LaPierre can’t turn them into umbrella-stands. Someone ought to hunt him, because apparently he likes that kind of thing.