The Big One That Got Away

Heard an interesting discussion on NPR’s Science Friday yesterday:

Research published this week in the Proceedings of the National Academy of Sciences says that predation by humans through hunting, fishing, and gathering has had significant influences on the rate of evolutionary change in a wide variety of species. Traits such as body size and first reproductive age shift significantly in species that are ‘harvested,’ the authors say.

“Fishing regulations often prescribe the taking of larger fish, and the same often applies to hunting regulations,” said Chris Darimont, one of the authors of the study. “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 and colleagues found that human predation accelerated the rate of observable trait changes in a species by 300 percent above the pace observed within purely natural systems, and 50 percent above that of systems subject to other human influences, such as pollution.

So basically, by removing the biggest animals from the population (of fish, Bighorn Sheep, etc.), we are speeding up evolution within those populations. It could be said we are managing the breeding programs of these animals through artificial means and causing them to select for unnatural traits. Which is kinda what has gotten us into the genetic mess we are in with purebred dogs. Granted there are very different methods and motivations at work but there is a similarity to my mind. I am not against hunting game or breeding dogs but I do think we can do both more responsibly, with an eye for the big picture. Because focusing on a set of trophy horns for the wall or winning a ribbon at a dog show seems to be leading us down the wrong path toward a dead end future.

Listen to the podcast of yesterday’s Science Friday show here.

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