Hi Vizeet, Heidelbergensis was killing adult male rhinos with sharpened sticks, while Neanderthal used fire hardened sticks for elephants. In hominid hands sticks and/or stones are really effective weapons.

Hello, A friend of mine has stayed with the bushmen many times. I have asked hime about their relationship with the big preadators they share their home with. He said that one time he arrived they gave him a rather small (and to my mind silly) spear and told him never to leave it behind as lions were close by. Other times they haven't bothered, when leopard tracks were spotted in the camp they gathered the children together and kept and eye on them.
He said that when out hunting in the bush one hunter stays awake at all times during the night, but that in general they have no fear of lions etc but more a healthy respect.

I don't really buy humanity (if that's the right term) being much of an agent in mega fauna extinctions. I honestly think it's an issue where a lot of scientific objectivity gets lost.

this series got me thinking, what with this big brain and all.... Big brains lead to big intelligence. Based on our understanding of the past can we predict the theoretical intelligence limit for our genetic line and how close we are to it? Are we getting smarter? Are the outliers in intelligence significant enough to be selected for? Ignoring any theories about the agricultural diet limiting our brain size etc... which may or may not be true... I'm thinking much bigger picture and I figure in time the agricultural stuff will all work itself out and we'll be back on track.

So where are we headed?

I'm sure you've seen this, right? Earliest Porotic Hyperostosis on a 1.5-Million-Year-Old Hominin, Olduvai Gorge, Tanzania

Hunting definitely by 1.5mya because scavenging would not provide enough meat to cause such nutritional adaptations (due to seasonal availability + actual amount of flesh available). Do you agree? If so, we can say hunting certainly happened by 1.5mya, if not the 2.6mya you suggested. Your idea that hunting predates aggressive scavenging is very interesting, and I would probably agree with it. The paper indicated that competition for meat was low in certain areas, so would that indicate more support for hunting before agressive scavenging?

Video: Daniel Wolpert, The Real Reason For Brains

Ah the motor cortex of primates serves a very important purpose for the eventual development of the first sharp rocks though , conscious control of individual muscle groups.

From Wikipedia:

"In the course of evolution a tendency to develop increasingly more complex brain structures and cortical densification can be observed. Cortical densification describes the increased shifting of control processes into the cerebral cortex. The motor cortex is a relatively recent development and occurs only in mammals. The execution of movement in fish, amphibians, reptiles and also birds is regulated by a core part of the brain called Archistriatum, in mammals the corresponding part of the brain is called Striatum, which is also involved in the execution of movement.

Especially primates have a highly developed motor cortex. In addition, separating them from all other mammals, they have many monosynaptic, thus direct connections from the motor cortex to the motor neurons in the brain stem and spinal cord. This leads to the conclusion, that only primates have a conscious, planned and finely graduated movement of single muscles, whereas the execution of movement for most other animals is probably more automatic and without the possibility of deliberate interference. In comparison to primates, ungulates have a relatively weakly developed pyramidal tract, which ends in the neck region of the spinal cord (Intumescencia cervicalis) and plays an important part in the production of facial expressions. As for dogs, while about 30% of the pyramidal fibres reach the loin region of the spinal cord (Intumescencia lumbalis), those fibres always end on interneurons, never directly on anterior horn cells.

Consequently, a complete impairment of the motor cortex in one hemisphere of the brain never leads to hemiplegia in non-primates, but rather to contralateral disorders concerning postural reflexes. Over the course of their evolutionary process, humans developed considerable control over their hands and articulatory muscles. Furthermore, humans have a uniquely high potential to learn new sequences of movement throughout their life.

Please note that no citations are provided for the above material."