the analog of groove in femur and crest in humerus to that of the Lower Backbone

The groove in the femur of Orrorin was created so that Orrorin is bipedal. To carry the extra heavy load and as such reinforcement of the femur was made in large part by a groove.

For stonethrowing, the reinforcements in the arm structure was the development of enlarged crests to accommodate larger muscle action.

But changes had to occurr to most of the body anatomy, not just to specific isolated points. And an intersection point of the body where Bipedalism meets Stonethrowing would be the Lower Back of the spinal region. To stonethrow the body itself becomes a sling and the weakest point of that sling would be somewhere in the Lower Back region. Likewise, when an animal changes from quadraped to biped, some special point of the body will be the weakest point in that changeover. The Lower Back is just that stress point.

So, I am wondering if the human lower back is vastly different than that of the chimpanzee. I am wondering if there is some groove to femur type of reinforcement to the Lower Back. Or like in the crest to humerus reinforcement in stonethrowing that a similar type of reinforcement appears in human lower back but not chimps.

In short, the groove in femur is a signature of bipedalism. The crests in humerus is a signature of stonethrowing. Similarly, I am hunting for a possible signature of both bipedalism and stonethrowing in the lower back region. If there indeed exists vast differences between man and chimp in the lower back, then physics alone can prove that these differences are due to biped and stonethrowing activity.

whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies

Looking at the Lower Backbone there is a plethora of crests. Whether there are any grooves is unknown. The iliac crests abound. Now I wonder to what extent there are crests in the Lower Backbone of chimpanzees in that they are not biped and they are nonstonethrowers (novelty at best).

Does anyone know how many crests exist in the human body as compared to a chimpanzee?

whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies

whole entire Universe is just one big atom where dots of the electron-dot-cloud are galaxies

Man, you're sick. Frans de Waal, evol-psych 22.9.01: Now, please, don't believe everything you hear about apes not throwing. Darwin was talking about monkeys, and Goodall's chimps may not have had much practice. In all research facilities with chimpanzees it is known how well apes throw. This is why projectiles are kept away from them, and why they mostly work with feces. They are deadly accurate, they swing around from the back of their cage and invariably 'nail' the one new face in the crowd with deadly accuracy. Ask any worker in such a facility: it's not rare, and no illusion! Out in the open, their skills are even more striking. I used to photograph the Arnhem chimpanzees from across the moat, where they were at about 10 m from me. I had to be extremely careful because young males tended to throw extremely well. They would see my eye go behind the camera, and all of a sudden it turned out they had a stone with them which they'd throw at me. Males more than females, mostly overhand. (Another tidbit in the debate whether they know if our eyes are for seeing or not .). Then there was the mother who came to the reception with her crying son. She complained that our chimps threw stones. After questioning and an account by a bystander it turned out that the boy had thrown first, and that the same stone had come back to him. The estimated distance of this case was 25 m. In short, the idea that apes can't throw is bogus. It has been around for a long time, but should be tested with apes who have had target practice. I invite all man-the-thrower advocates for a visit - at least if they don't mind some smelly stuff coming their way!