humans hunt

Humans hunt, their prey gets smaller

• U.S. researchers reported that hunting has a profound impact on animals and plants, driving an evolutionary process that makes them become smaller and reproduce earlier. Collecting of 29 different species shows that under human pressure, creatures on average become 20% smaller and their reproductive age advances by 25%.
  
  
• The human tendency to seek large "trophies" appears to drive evolution much faster than hunting by other predators, which pick off the small and the weak.
  

• Darimont and colleagues calculated the rates of trait change with a metric called the "Darwin," after Charles Darwin, who developed the theory of natural selection to help explain evolution.
  

• They studied changes in the size of fish, limpets, snails, bighorn sheep and caribou, as well as two plants the Himalayan snow lotus and American ginseng. In virtually all cases, human-targeted species got smaller and smaller and started reproducing at younger ages making populations more vulnerable. The findings fit in with other studies that suggest many fish are over-harvested.