Lucy's muscles suggest she was proficient at bipedalism

[dlamberth]

"Australopithecus afarensis, the extinct species to which Lucy belongs, could probably straighten its knee joints, extend its hips and stand up straight like modern humans."

3.2 million-year-old human ancestor 'Lucy' had massive leg muscles to stand up straight and climb trees

Australopithecus afarensis, the extinct species to which Lucy belongs, could probably straighten its knee joints, extend its hips and stand up straight like modern humans.

www.livescience.com

 

[AV1611VET]

"Australopithecus afarensis, the extinct species to which Lucy belongs, could probably straighten its knee joints, extend its hips and stand up straight like modern humans."

Looks like ol' Lucy was more human than they thought she was, doesn't it?

 

[Occams Barber]

Looks like ol' Lucy was more human than they thought she was, doesn't it?

Not really. Lucy is the classic hominin, with a mix of characteristics. If you look at the skull you'll notice how different it is to Homo sapiens (you and me) while the lower anatomy (and musculature) are more human.

Reconstruction of Lucy's skull at the Naturhistorisches Museum Basel, based on a lower jaw bone and several other skull fragments.

Her small skull, long arms and conical rib cage are like an ape's, but she has a more human-like spine, pelvis and knee due to walking upright.​

Johanson thought Lucy was either a small member of the genus Homo or a small australopithecine. Only after analysing other fossils subsequently uncovered nearby and at Laetoli in Kenya did scientists establish a new species, Australopithecus afarensis, four years after Lucy's discovery.

At the time, Au. afarensis was the oldest hominin species known, although far older species have since been found.​

​

Australopithecus afarensis, Lucy's species

Thanks to an extraordinary fossil called Lucy, Australopithecus afarensis is one of the best-known early human relatives.

www.nhm.ac.uk

​

​

OB

 

[Hans Blaster]

"Australopithecus afarensis, the extinct species to which Lucy belongs, could probably straighten its knee joints, extend its hips and stand up straight like modern humans."

3.2 million-year-old human ancestor 'Lucy' had massive leg muscles to stand up straight and climb trees

Australopithecus afarensis, the extinct species to which Lucy belongs, could probably straighten its knee joints, extend its hips and stand up straight like modern humans.

www.livescience.com

That sentence in the quote box from livescience is rather odd. The anatomy of the skeletons of Au. afarensis makes it quite clear that they stood upright and walked as their primary locomotion. It's in the feet, the hips, the knees, and the skull. A regular upright posture is *not* some new discovery.

 

[USincognito]

Au. afarensis is just more evidence that bipedalism evolved before a big brain.

 

[Occams Barber]

Au. afarensis is just more evidence that bipedalism evolved before a big brain.

That was a time when we could walk the walk but not talk the talk.

OB

 

[jayem]

That sentence in the quote box from livescience is rather odd. The anatomy of the skeletons of Au. afarensis makes it quite clear that they stood upright and walked as their primary locomotion. It's in the feet, the hips, the knees, and the skull. A regular upright posture is *not* some new discovery.

Very true. But upright posture and bipedal locomotion also require adaptation of the spinal column. Which is an equally, if not more, important adaptation than the feet, knees, hips, and pelvis. If we assume Lucy's species were the earliest bipedal primates, on an evolutionary time scale, 3.2 million years ago is not that far removed from now. All the bugs haven't been worked out yet. This may be a reason why degenerative disc disease and other causes of chronic back pain are so common. (In modern society, obesity is definitely a factor, too.) And since back problems don't usually interfere with reproduction, there's no natural selection pressure to favor stronger spines.

 

[Astrid]

Very true. But upright posture and bipedal locomotion also require adaptation of the spinal column. Which is an equally, if not more, important adaptation than the feet, knees, hips, and pelvis. If we assume Lucy's species were the earliest bipedal primates, on an evolutionary time scale, 3.2 million years ago is not that far removed from now. All the bugs haven't been worked out yet. This may be a reason why degenerative disc disease and other causes of chronic back pain are so common. (In modern society, obesity is definitely a factor, too.) And since back problems don't usually interfere with reproduction, there's no natural selection pressure to favor stronger spines.

I'm more intrigued with how they fended off
predators than just zactly how they walked

 

[Shemjaza]

I'm more intrigued with how they fended off
predators than just zactly how they walked

I figure bands of, what are effectively, slightly more intelligent and slightly more mobile chimps aren't worth the trouble for most predators, a lot of the time.

 

[Astrid]

I figure bands of, what are effectively, slightly more intelligent and slightly more mobile chimps aren't worth the trouble for most predators, a lot of the time.

What trouble could they give?

 

[jayem]

I'm more intrigued with how they fended off
predators than just zactly how they walked

Bipedalism frees the upper extremities to use clubs and rocks as weapons for self defense.

 

[Shemjaza]

What trouble could they give?

Individually not much... but large primates who are good at coordinating just aren't worth the trouble when there are bigger and dumber things to eat.

 

[GodLovesCats]

Au. afarensis is just more evidence that bipedalism evolved before a big brain.

Scientists already knew about homo erectus, which came later. At the time, it was believed to be the first bipedal hominid, hence its name.

 

[GodLovesCats]

Bipedalism frees the upper extremities to use clubs and rocks as weapons for self defense.

And do many other activities. It is known early hominids (before Neanderhals) used tools.