We've been seeing this for years....
May. 27th, 2004 10:05 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
senoritafish"Researchers have found that as fishermen hauled away the biggest fish, cod became smaller and produced smaller offspring. It's a rule every weekend angler knows: Throw back the small fish. It helps the population survive long term. Right? Wrong. Mounting evidence suggests that by harvesting only the biggest fish - or biggest mammals, for that matter - mankind is unwittingly forcing many species to evolve rapidly. This process, called "contemporary evolution," isn't taking place over centuries. It's on a fast track that can happen within a few decades."
http://www.csmonitor.com/2004/0520/p15s01-sten.html
It's why for quite a few species, there are regulations for "slot limits" - i.e. you can only take animals bigger than a certain size (so hopefully, they'll have had a chance to spawn at least once), and smaller than the largest sizes, leaving the really large animals that produce the most eggs. However, if all the largest animals are already gone.....
http://www.csmonitor.com/2004/0520/p15s01-sten.html
It's why for quite a few species, there are regulations for "slot limits" - i.e. you can only take animals bigger than a certain size (so hopefully, they'll have had a chance to spawn at least once), and smaller than the largest sizes, leaving the really large animals that produce the most eggs. However, if all the largest animals are already gone.....
