Two critical advances were bipedalism and encephalization.

两个关键进展，两足行走和脑的发达。

The debate over the origins of human bipedalism has been argued since Charles Darwin's day, dividing into two competing models.

围绕人类两足行走起源的争论从查尔斯·达尔文时代就开始了，分为相互不让的两种模式。

'the debate over the origins of human bipedalism has been argued since Charles Darwin's day, dividing into two competing models.

围绕人类两足行走起源的争论从查尔斯·达尔文时代就开始了，分为相互不让的两种模式。

That proved bipedalism did not evolve on the savannah, but since hair does not fossilise, it is hard to establish when the hominids began to lose it.

这证明，两足动物的演化史并不是在大草原上进行的。但是，由于毛发不会变成化石，因此很难确定原始人类在什么时候开始失去毛发。

Known as bipedalism, our habitual upright posture is unique in the animal kingdom and has arisen through specific complementary adaptations of the body and brain.

作为两足动物，我们直立的习惯在动物界是独一无二的，这种习惯也是为了适应我们的身体和大脑而采取的一种特殊补偿。