Early Humans

[ysabetwordsmith]

This ancient fossil could rewrite the story of human origins

A seven-million-year-old fossil may rewrite human origins, showing our ancestors were walking upright far earlier than anyone expected.

Scientists may have cracked the case of whether a seven-million-year-old fossil could walk upright. A new study found strong anatomical evidence that Sahelanthropus tchadensis was bipedal, including a ligament attachment seen only in human ancestors. Despite its ape-like appearance and small brain, its leg and hip structure suggest it moved confidently on two legs. The finding places bipedalism near the very root of the human family tree.


This makes sense given how many primates are capable of walking on two legs and do so whenever it offers them an advantage. With the potential already there, all it would take is an environment where bipedalism worked better than other methods -- like Africa's growing savannas.

Comments

The small brain intrigues me

[dialecticdreamer]

The smaller brain case suggests that bipedalism improved survival and nutrition, which then contributed heavily to the development of bigger brains, generation after generation.

It's the exact opposite of the theory that was the gold standard when I was in school.

In the same way, better eyes and better hearing probably preceded the bipedalism by another half million years or more, for the same reasons.

Re: The small brain intrigues me

[ysabetwordsmith]

>> The smaller brain case suggests that bipedalism improved survival and nutrition, which then contributed heavily to the development of bigger brains, generation after generation.<<

Exactly. The thing to remember is that brain tissue is expensive. No matter how useful it is, you have to be able to support the metabolic demand. So there's an odd bit of back-and-forth where you need enough intelligence for bipedalism to be feasible and useful -- for instance, understanding that seeing farther is an advantage and using that to secure more resources or avoid predators -- before it can increase the diet enough to support a bigger brain for things like talking.

>>In the same way, better eyes and better hearing probably preceded the bipedalism by another half million years or more, for the same reasons.<<

Well yeah, primates have been developing those all along. Good vision is essential for determining fruit ripeness and troopmate faces; being able to holler in a forest is necessary for communication.