(Photo: S.J. Bennett)
For the first time, scientists have discovered that a species other than humans has a handed dominance. Just as humans are mostly right-handed, kangaroo species are mostly left-handed. Lead researcher Yegor Malashichev and his colleagues found this tendency among eastern grey kangaroos, red kangaroos, and red-necked wallabies. The researchers think that handedness may result from a species evolving into an upright posture and walking on the hind legs. BBC News reports:
In terms of handedness, Dr Malashichev said this confirmed for the first time that "we are not alone in the Universe; we are two - humans and kangaroos".
He and his colleagues suggest that their discovery is an example of "parallel evolution". This is because handedness seems to have appeared in primates, which belong in the group of placental mammals, as well as the marsupials in the new study, but not in related animals across these two branches of the evolutionary tree.
-via National Geographic