人类是唯一有下巴的灵长类动物——现在终于知道原因了

BIOLOGISTS have long debated why Homo sapiens evolved a prominent lower jaw, but this unique feature may actually be a by-product of other traits shaped by natural selection. other evolutionary changes. probably directly selected – meaning something about them was favorable enough to shape their evolution. But the other six traits appeared to be unaffected by selection or simply by-products of evolution for other non-chin traits (PLOS One, doi.org/hbn72k). beneath the braincase instead of projecting forward like it does in chimpanzees, von Cramon- Taubadel explains. Meanwhile, larger brains and dietary shifts reduced the need for large front teeth and powerful chewing muscles, shrinking the lower face and jaw. …