What makes monkeys strong

Our fine motor control prevents great feats of strength, but allows us to perform delicate and uniquely human tasks, Walker writes in the April issue of the journal Current Anthropology. Walker's hypothesis stems partly from a finding by primatologist Ann MacLarnon, who showed that relative to body mass, chimps have much less gray matter in their spinal cords than humans have.

Spinal gray matter contains large numbers of motor neurons — nerves cells that connect to muscle fibers and regulate muscle movement. But if this is true, it remains unclear why the dominance of slow-twitch fibres extends to the upper body as well as the lower. It may be that the distribution of different muscle types across the body is dialled up or down by the regulation of different genes.

But Dr O'Neill says that only more research can answer that question. Follow Paul on Twitter. Image source, AFP. Chimps do appear to be stronger than us, but not by as much as we often think.

Puny human? Fast vs slow. Such physical lack of control can potentially lead some chimps to become more aggressive when physical. In Thursday's case, however, an internal investigation by the Jane Goodall Institute near Johannesburg showed that the chimps might not have intended to be malicious, Eugene Cussons, director of the institute, told "Good Morning America" today.

The two chimps saw Oberle's crossing the fence into the chimps' space as a violation of their territory, prompting them to take action, Cussons said. They directed the violence towards Andrew whom they feel was infringing on their territory.

Chimpanzees have a wide range of emotions and they are similar to what humans experience, yet they are known to have erratic and unpredictable impulses, Ross said. The emotional impulses also play a role in how aggressive they can become, he said.

This makes it hard to separate the effects of muscle arrangement, the contributions of tendons, or the effect of overall body shape from the actual strength of the muscles. So keeping this in mind, a team of US researchers dug deeper into the wealth of research conducted between and and came to the conclusion that a more accurate interpretation of the data is that while chimpanzees are consistently stronger, they are on average only about 1.

To put this number to the test and discover why chimp muscles were stronger than ours, the team isolated muscle fibres and tested their overall force and velocity as they contracted. They also examined the tissue's distribution of 'motor proteins' called myosin. Muscle fibres tend to come in two varieties — slow-twitch and fast-twitch, each of which with its own characteristic pattern of myosin chains.