FAST VS SLOW. “Burrows et al. (2014) demonstrated that humans have a greater percentage of fast-twitch fibers than slow-twitch fibers, and the relationship holds true for both the closely related chimpanzees and the distantly related rhesus macaques. However, humans have a significantly higher percentage of slow-twitch myosin fibers than either chimpanzees or rhesus macaques.”
http://onlinelibrary.wiley.com/doi/10.1111/joa.12440/full