Human hunting speeds up evolution of prey - January 13, 2009
The impact of human hunting on wildlife populations doesn’t end with the individual animal deaths — it also forces harmful evolutionary changes on animal populations, according to new research.
Although previous research has shown that hunted species evolve in response to predation, it was unclear whether hunting affects the rate of evolution.
Thus, evolutionary biologist Chris Darimont of the University of California, and his colleagues assessed how morphological characteristics of 29 species — including fish, limpets, snails, bighorn sheep, and two plants — changed over time.
Their findings, published in Proceedings of the National Academy of Sciences, show that human-hunted species have undergone the most rapid change, and that this has forced dramatic shifts in features such as average size and age of reproductive animals.
"The public knows we often harvest far too many fish, but the threat goes above and beyond numbers," Darimont said in a press release. "We're changing the very essence of what remains, sometimes within the span of only two decades. We are the planet's super-predator."
Other predatory animals hunt young and nearly-dead meals, partly explaining why they have less of an effect on population genetics, Darimont told the New York Times.
Ironically, this means that some rules that are designed to conserve animals might be having detrimental effects.
"Hunters are instructed not to take smaller animals or those with smaller horns. This is counter to patterns of natural predation, and now we're seeing the consequences of this management," Darimont told Reuters.
Another cause is that humans will harvest many more animals per year than other hunters.
Darimont hopes these findings will serve as a wake up call for conservation managers. "We should be mimicking natural predators, which take far less and target smaller individuals," he says.
Daniel Pauly, of the Fisheries Center at the University of British Columbia, told the New York Times that the new findings “make sense”.
More: Darimont's last appearance on the Great Beyond, discussing wolf food preferences: “We had a literal mountain of wolf shit. In Mum’s defense, and in my defense, we autoclave it so all the parasites are rendered inviable."
Image: Duck hunting / USFWS
Comments
I doubt that these human induced changes are inherently bad. It is just causing some species to evolve in a different direction. Not only that, but I don't think we should be mimicking the less powerful hunters as far as the quantity and type of prey we choose. Is it to any of our benefit to give up our super-predator status? I doubt it, doing so would only mean a better life for the animals at the cost of a far diminished quality of life for us. I vote humans first.
Posted by: Kevin | January 13, 2009 10:37 PM