Why do female African elephants no longer grow tusks? 　　In everyone’s impression, evolution is a very long process, especially for some key traits for organisms, but with the continuous increase of human hunting and poaching of wild animals, this situation may have changed. Evolution, under the effect of artificial selection, started to run wild. 　　A 15-year civil war ravaged Mozambique from 1977 to 1992. In order to obtain war funds, rampant poaching has caused a sharp decline in the number of elephants in Gorongosa National Park, and more than 90% of African elephants have lost their tusks. Object-wise, ivory = life. 　　After the war, although poaching has disappeared in Gorongosa…