If you ever find yourself in a boxing match with a kangaroo, watch out for its left hook. A Russian biologist named Yegor Malashichev says that the marsupials tend to be left-handed—or rather, left-pawed.
Figuring out how some species of kangaroo and wallaby evolved to be southpaws could help scientists understand how humans evolved handedness. Like us, these creatures from Down Under are bipedal: they stand on two legs, and the link between walking styles and hand preference may be more than a coincidence. The origins of handedness are much debated, but one leading theory suggests that upright posture is the key to developing a favorite side.
“It seems like bipedalism is a triggering factor that pushes forward the evolution of handedness,” says Malashichev, whose team reports their work this week in Current Biology. “Standing on your hind legs frees up your forelimbs, and you can do with them what you like.” … Read more —> http://www.smithsonianmag.com/science-nature/kangaroos-are-lefties-and-can-teach-us-about-human-handedness-180955630/#fejsR8GC1qhDzCYQ.99