Unnatural Evolution: Fishing Eliminates Cod Adapted for Shal

[Homunclus]

http://blogs.discovermagazine.com/8...ion-cod-fishing-drives-fish-to-deeper-waters/

The fishing boats that relentlessly sweep the northern Atlantic Ocean looking for cod may be changing the genetics of the species, researchers say, in a case of "fisheries-induced evolution." Commercial fishing techniques used to harvest the valuable fish are wiping out the cod that swim at shallower depths, which have a genetic variant that's not seen in cod that stick to deeper water. If overfishing of cod continues, the research team believes the genetic variant will be lost all together

"Man the hunter has become a mechanised techno-beast," the team writes. "Modern fisheries are uncontrolled experiments in evolution

Previous studies have suggested that hunting and fishing are removing the largest animals from species' gene pools: For example, stags with the largest antlers are routinely hunted and may therefore fail to reproduce, while smaller stags with scrawny antlers,the ones least prized by hunters,may live long, fruitful lives.

cod in the Icelandic fishery are becoming sexually mature while still smaller and younger

We think this too is an evolutionary response to the selective pressure of fisheries,

An example of evolution on action and of the impact of men on the ecosystems. A perfect two on one