The Most Amazing Fact About Koalas
Koalas are absolutely fascinating creatures. Females have two vaginas, and males have a bifurcated penis split into two prongs. They also have one of the smallest brains in proportion to body weight of any mammal, perhaps an adaptation to their eucalyptus diet, which probably isn't nourishing enough to support a large brain. Koalas also digest their food for as long as 200 hours!
But all of those incredible factoids pale in comparison to this one: koalas have fingerprints that are almost indistinguishable from human prints! (Below: a koala's print is on the left and a human's is on the right.)
Maciej Henneberg, a forensic scientist and Wood Jones Professor of Anthropological and Comparative Anatomy at the University of Adelaide, originally made the discovery back in 1996. As reported by NewScientist:
With his colleagues Kosette Lambert and Chris Leigh, Henneberg obtained three male koalas that had been killed by cars and a 46-year-old female chimpanzee that had died in captivity. Using a scanning electron microscope, they compared the koala and chimp prints with those from humans. Strangely, given that chimpanzees are our closest relatives and themselves have human-like fingerprints, the koala prints were even more like those of humans.
Even more amazing, primates and koalas' ancestors branched apart between 70 and 80 million years ago, suggesting that both independently evolved their fingerprints.
While the modern human experience with fingerprints centers around crime and identification, the mesmerizing whorls on our fingers (and chimpanzees' and gorillas') did not evolve for that purpose. One theory is that fingerprints function as 'tactile enhancers', amplifying vibrations to boost the sense of touch. Another is that fingerprints boost an individual's ability to grasp objects.
The latter reason makes the most sense for why koalas – who spend much of their life in the trees – have fingerprints. Surprising and wonderful chance made their prints so much like ours.