直立行走是“从猿到人”的重要标志,但至今没发现这一过渡环节的化石证据。对此,德国科学家施伦克不久前在一个研讨会上提出了自己的看法。他认为,也许古人的直立进化过程并不是持续性的,而是随着地域、环境的改变多次反复。热带雨林草原化改变了古猿的生活环境和食物来源,迫使它们从树上来到地面。在草原上,它们爬着就能寻找食物,但有时需要站起来摘树上的食物,也经常需要站着渡 Upright walking is an important sign of “from ape to man,” but so far no fossil evidence of this transition has been found. In response, Schlenk, a German scientist, put forward his own opinion at a seminar not long ago. He believes that perhaps the ancients’ evolutionary process of erection is not sustainable. Rather, it is repeated many times as geographical and environmental changes. Rainforest Prairie changes the living conditions and food sources of the apes, forcing them to come to the ground from trees. On the grasslands, they crawl to find food, but sometimes they need to stand up and pick up food from trees and often need to stand by