In nature, predators usually go after the weakest of the prey – the oldest or youngest, the injured or ill. It makes sense; these animals are easier to catch, even if they’re not always the meatiest. This ensures that wildlife populations stay strong, as the weakest animals get culled while the strongest and healthiest survive to pass on their genes.

We humans are different. We’re often out to prove something, and so, with our fancy hunting or fishing gear, we go after the biggest and strongest animals.

Hunting and harvesting done by humans has the opposite effect. New research published in the Proceedings of the National Academy of Sciences shows that many of our current hunting and fishing practices not only reduce population numbers but also cause dramatic and often negative changes in the behaviour, size, and characteristics of targeted species.