This one’s a little of the beaten path for this site, since it’s not physics or even anything I normally follow as a hobby. But along with science and many other things I’m a bit of a firearms enthusiast, and since guns are closely connected with hunting it probably wasn’t unlikely that I’d come across this Livescience piece about the genetic implications of hunting.
The thesis is so simple as to be almost self-evident. Hunters tent to hunt for the largest and most impressive animals, especially when hunting seasons are short and bag limits are small.
This unnatural selection, a practice that dates back decades and more to hunters like Teddy Roosevelt who sought trophy animals before there were restrictions, is forcing “reverse evolution,” according to a recent article in Newsweek.
Biologist Marco Festa-Bianchet of the University of Sherbrooke in Quebec found a 25 percent decline in the size of horns on bighorn sheep over the past 30 years, and both male and female bodies are getting smaller.
And the author goes on to cite some numbers involving other animals. It’s not terribly surprising. Nonetheless, it can be misinterpreted and in fact the author starts off the piece with a misinterpretation:
Survival of the smallest is not exactly what Darwin had in mind, but in some animals species, humans may be forcing a smaller-is-better scenario, and the ultimate outcome may be species demise.
Neither Darwin nor nature cares in the least about size as such. If it were so, I’d be a huge dinosaur typing this on a huge keyboard designed by dinosaur engineers for use with claws. But in fact I’m a fairly small and puny animal who is part of a species that’s nevertheless managed to do pretty well. All that matter is how well you reproduce. Do it successfully and your species will grow, don’t do it successfully and it won’t. If smaller happens to avoid hunting, than small is what’s going to be around to breed.
However, genetic problems can present themselves. Some locations in Africa have had greatly increased populations of deformed tuskless elephants, since obviously those will have a much smaller chance of being poached. These kinds of features hurt the animals’ chance of natural survival, potentially threatening the entire species.
What can hunters do about it? All of the hunters I know hunt primarily for the meat and the enjoyment of being in nature and part of the food chain in a much more natural way than eating chemically saturated slaughterhouse cows. Some are interested in trophy animals (though the meat is never wasted), but it’s a much less prevalent motivation. Probably a good thing to do would be to set aside genetic preserve locations where smaller animals were deliberately hunted, allowing larger ones to build up. These could be transplanted into regions experiencing diminution. Another possibility could be providing incentives for hunting smaller animals, such as higher bag limits or lower cost licenses. Obviously this could only work for animals which are not threatened, but many game species such as deer are so common as to be nowhere near that point. One more option (sort of the converse of the previous) could be to set inverse size limits – put a comparatively small limit on the number of deer above a certain size that may be taken. I think hunters would likely support all of this if it could be shown to improve the quality of hunted species.
This is for the US and other developed nations which already have a solid and time-tested symbiotic relationship between hunters, prey species, and the cultural and legal rules of the hunt. In places where poaching is a serious problem the top priority will have to be stopping poachers. I suspect the Whale Wars crew would never do something as declasse as buying some rifles and helping guard African wildlife preserves, but it would be a lot more useful than their thus far ineffective petty harassment of one Japanese whaling vessel.
Those are just some ideas from a guy who knows very little about population genetics or hunting. It’s still an interesting thing to think about.