FISHING and hunting by humans may drive evolution in a way unlike anything else on Earth, and the rapid changes triggered in wild species risks severe damage to ecosytems.
, an evolutionary ecologist at the University of California at Santa Cruz, and his team, reviewed 34 studies that measured how fast traits such as body size and growth rate had changed in 29 species that people harvest for food.
The average rate of change was three times as fast as comparable changes seen in unhunted populations, they found (Proceedings of the National Academy of Sciences, ).
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It was well known that hunting and fishing, which often target the largest individuals, can cause species to become smaller and mature more quickly. However, Darimont’s study is the first to show that this effect occurs for species ranging from cod to caribou, and that these species change far more quickly than they otherwise would, says , an evolutionary biologist at McGill University in Montreal, Canada.
Rapid changes in size may threaten ecosystems by disrupting size-based interactions such as predation and competition, says Darimont. For example, smaller fish may no longer be big enough to eat species they once preyed on.
