I just found this insanely funny..:D
The ancestors of humans, apes and monkeys may have taken to the trees because of their small body size.
Scientists have long wondered why early primates inhabited forest canopies, given that climbing appears to consume more energy than walking.
US researchers studied primates climbing and walking on treadmills.
They say there was no difference in energy consumption for small primates, giving clues to how their ancestors entered the trees 65 million years ago.
Dr Jandy Hanna of Duke University, Durham, North Carolina, said the data suggested that the earliest primates were able to exploit a new environment without added cost if they remained small.