Scientific American tries to explain:. They say that a big reason chimps can lift heavier things than we can, is that they have less control over how much muscle they use each time they lift. Humans have a lot more fine motor control than chimps: we can do things like play a guitar, paint teeny tiny lines or thread a needle. We might not be able to fight off a chimp, but we can make some pretty amazing needlepoints.
Image: David Heyes. By Michael Le Page. Looks like I really am a softy, after all. Chimpanzees do have stronger muscles than us — but they are not nearly as powerful as many people think. This result matches well with the few tests that have been done, which suggest that when it comes to pulling and jumping, chimps are about 1.
His findings suggest that other apes have similar muscle strength to chimpanzees. To create an accurate computer model of how chimps walk, the researchers needed to find out whether their muscles really are exceptionally strong. These differences in muscles likely emerged within the past 7 million years, when early human ancestors developed more slow-twitch muscle fibers which are good for endurance than fast-twitch muscles which are good for speed and punch , according to Matthew O'Neill, an assistant professor at the University of Arizona College of Medicine in Phoenix.
O'Neill led the research group that reported the findings, which were published today June 26 in the journal Proceedings of the National Academy of Sciences. This greater number of slow-twitch fibers may have evolved because it gave early humans the advantage of being able to travel long distances and forage, and allowed them to rely less on powerful movements for survival and fitness, O'Neill said.
For years, scientists have suspected that chimpanzees are more powerful than humans , but that suspicion was based largely on anecdotal evidence. Adult chimps are generally smaller than adult humans; on average, the apes weigh about lbs.
Therefore, it has been difficult to accurately compare strength between the two primates. The notion that chimpanzees and other apes have superhuman strength dates back first to tall tales from European explorers in sub-Saharan Africa in the early 19th century and then to research in the s by biologist John Bauman, who studied chimps in zoos.
In a series of studies later revealed to have poor methodology, Bauman found that chimps could pull weights five times heavier than the beefiest college football players could. According to ideas put forward in previous work, the difference might be accounted for if chimpanzee muscles were able to generate more force per area, or, alternatively, if chimp muscle was able to shorten faster than human muscle - helping increase its power output.
Dr O'Neill and his colleagues set out to test these ideas and others, by directly measuring the properties of muscle fibres taken from chimps that had been frozen after death. Along with cardiac muscle and smooth muscle, skeletal muscle is one of the three main muscle types, and is mostly found attached to bones via the bundles of collagen known as tendons. However, they did find key differences in the length of the fibres - chimp muscle fibres tend to be longer than corresponding ones in humans - and in the distribution of different muscle fibre types.
Chimps possess about twice the amount of "fast-twitch" muscle fibre. This type of fibre contracts quickly and is useful for rapid movements such as sprinting. But fast-twitch fibres have a downside: they quickly tire. By contrast, corresponding human muscles are dominated by "slow-twitch" muscle fibres, which contract more slowly, but keep going for longer.
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