进化生物学家至今也不十分清楚人类(以及绝大多数四足动物)为何每只手长有5根手指。如果我们拥有6根手指,我们的生活又会变成怎样?或者说,额外的一根手指对我们到底是利大于弊,还是弊大于利?额外的一根手指能够让我们更轻松地完成一些任务。我们可以演奏更复杂的乐器,提升打字速度,抓握物体时也更为牢固。但最大影响应该是在数学方面。如果人类的每只手拥有6根手指,现在的计数系统将完全是另一番景象。绝大多数人采用10进制,人类学家 So far, evolutionary biologists have not known why human beings (and most quadrupeds) have five fingers per hand. If we had 6 fingers, how would our life turn out? Or would it be more harm than good or more harm than good to have an extra finger? An extra finger made it easier for us to do something task. We can play more complicated instruments, improve typing speed, and get stronger when gripping objects. But the biggest impact should be in mathematics. If human beings have six fingers in each hand, the current counting system will be completely different. Most people use the decimal, anthropologist