Question

A fossil of a new primate species is discovered. Scientists hypothesize that the species traveled long distances without putting their hands down on the ground, and used tools. If this hypothesis is true, which trait would the fossil most likely have?

A. a foramen magnum at the back of the skull
B. a curve in the lumbar region of the spine
C. a femur angled outward
D. an opposable big toe

Answer 1

Well, A is referring to a hole in the skull where the spinal cord and brain stem exit. B is referring to the S shaped spine of humans Hint, creatures like cats, dogs, bears, rats, armadillos, deer, lizards, etc have a C shaped spine. Outward femurs angle legs away from the main body, and I am not even going to deal with D.

Answer 2

Yep, I ruled out D immediately, and I didn't consider A.

Answer 3

Well, but I was considering how those primate species were relying on walking with only two legs...

Answer 4

However, those primates were still evolving, so their spinal cord may have still been hunched.

Answer 5

I'm afraid to say anything, 'cause I'm afraid if I do, it won't be helpful. (Including this statement.)

Answer 6

Then again, if it were hunched, then chances are that the primate would touch the ground, which isn't what the question is asking for.

Answer 7

Well, given that the travel long distances and use tools, it seems that they would have to have evolved an efficient method of walking upright.

Answer 8

True. I will go with C then. Thank you. :)

Answer 9

I agree with C! Not that that matters, but still.

Answer 10

No!

Answer 11

O.O

Answer 12

Wait what?

Answer 13

If I understand B correctly, they are referencing the S-curve spine that is the way humans have their spine. Otherwise there is just a C curve of the spine.

Answer 14

Yeah, C was wrong... :P

Answer 15

I AM NOT TO BE TRUSTED! NOOOOOOOOOOOOOOO!!!!

Answer 16

Kyan...your comments aren't helping, honestly,

Answer 17

I'm sorry.

Answer 18

Well, a bit late now but this site has some good info: http://efossils.org/book/knee-distal-femur-and-proximal-tibia

Answer 19

Okay. Thanks for your help.

Answer 20

So, there are the spine types (what I drew) You can see the line down the S spine represents how the S curve allows the weight of the head to be inline with our hips, from a side view.

Answer 21

I see.

Answer 22

Fun fact, humans have horribly inefficient running, but AMAZINGLY efficient walking, especially over long distances.

Answer 23

I agree. XD

Answer 24

On the other hand, mammals that run with four legs are much more efficient in running. Humans seemed to have developed a disliking for running. XD

Answer 25

You know there is also a hypothesis that humans evolved upright walking b/c we used a tool like a spear to hunt. I think it is discounted now.