Why did humans leave the trees?

Answer 1

Answer 1

Humans did not leave the trees for the simple reason that they were never in the trees to start with.

Our forefathers, ape-like creatures, eventually left the trees most likely because they 'learned' to walk up-right, use bones and stones as tools and weapons and caves for shelter. Since there was no longer an advantage in being able to climb trees and life there, we simply lost that ability.

Other animals have experienced similar adaptations. The Kakapo for example is a kind of parrot which lives solely in New Zealand and which has lost the ability to fly for the simple reason that it did not have any enemies, no predators which could attack and eat it. It therefore did not need the ability to fly away when attacked and as a result, it lost that ability.

There is a very interesting video of a talk by Douglas Adams recorded at the University of California in which he describes the interesting and evolutionary adaptations of the Kakapo and other animals. The video is nearly 90 minutes long but educational and very funny. See link below in Related Links.

Answer 2

There are various hypotheses explaining what might have driven the ancestors of H. sapiens to adapt to a life in the plains rather than in and amongst trees. One is that a climatological chance slowly drove certain tribes of apes from their preferred habitates; another factor may be increasing population numbers and competition; it may have been simple curiosity or chance, that drove primates to try their luck at first the outskirts of their preferred habitat and then beyond them. Frankly, I doubt we'll ever know with any certainty what, out of a million possibilities, brought our ancestors from the trees.