21 SEP 2011 by ideonexus
Australopithecus afarensis' Hip Bone Indicates She Could ...
When Lucy’s hundreds of fragments were assembled, she turned out
to be a female of a new species, Australopithecus afarensis, dating back
3.2 million years. She was between 20 and 30 years old, 3.5feet tall,
weighing a scant 60 pounds, and possibly afflicted with arthritis. But
most important, she walked on two legs.
How can we tell? From the way that the femur (thighbone) connects to
the pelvis at one end and to the knee at its other. In a bipedally
walking primate like ourselves, the fem...The bone tilts to bring the knees inward, like it does in humans, but not in chimps, who waddle because they are bow-legged.
20 MAY 2011 by ideonexus
Skeletal Similarities in Mammals
What a piece of work is the mammalian skeleton. I don't mean it is beautiful in itself,
although I think it is. I mean the fact that we can talk about 'the' mammalian skeleton at all: the fact
that such a complicatedly interlocking thing is so gloriously different across the mammals, in all its
parts, while simultaneously being so obviously the same thing throughout the mammals. Our own
skeleton is familiar enough to need no picture, but look at this skeleton of a bat. Isn't it fascinating
ho...There are corresponding bones across species, evolved into other functions.