Koala “bears” are a marsupial from Australia known for looks many humans find adorable. They are widely known by sight but not fully understood. The small creatures are posing some questions scientists haven’t answered.
One is the fact that they have fingerprints and those fingerprints are closer to humans than one would expect. After all our common ancestry ended 100 million years ago. The fingerprints are so close some suggest experts have difficulty telling them apart from human prints.
Also, a recent study at the University of Illinois says the koalas can shed light on the origins of the human genome.
But first the basics. Phascolarctos cinereus is not really a bear, although it superficially resembles one. It is instead a marsupial mammal. Marsupials give birth to very immatrue young that climb into a pouch to mature. Koalas are close to a yard in length and can weigh up to 30 pounds. They eat only eucalyptus leaves and have an internal organ that helps digest the not-very-nutritious food. As a result of limited nutrition they are sluggish and spend much time sleeping.
Like many other animals they have suffered at human hands, their desirable fur dooming them by the thousands. As a result of major slaughter they declined in numbers and today are at risk, like tigers and mountain lions, of inbreeding or local extinction.
One of the many unusual things about them is their hands. According to Live Science the mystery of koala fingerprints may be solved. Unlike their close relatives, wallabies and kangaroos, koalas climb trees and grasp with their hands, as do our primate relatives. The latest thinking is that the fingerprints give an advantage to creatures climbing and grasping. Why they are almost identical to human fingerprints is not as clear.
Meanwhile, koalas may shed light on the human genome. According to Scientific American a retrovirus moving through the koalas population may help us understand the evolution of our genome. Apparently, koalas and humans both have about 26,000 genes. About 8 percent of human genes are descended from viruses that began to infect humans. Some viruses eventually work their way into the genome and pass themselves down the generations, eventually becoming benign.
That process is currently playing out in koalas. Some populations are showing the impacts of a retrovirus. That virus appears to be working its way permanently into the koala genome. That is allowing scientists to study how viruses manage to move into an animals genome and how the animal adapts.
In other evolutionary news scientists working on the genetics of Australian wild dogs called dingos have made progress in that field. They are not descended from domestic dogs but have their own genetic line. They appear to be descended from a wild dog not a wolf or a domestic dog. Some think they came to Australia with early seafarers but the difficulty they have digesting starch casts doubt on that. The question still remains whether dingos were ever domesticated as some believe.
Editors Note: The links to the University of Illinois and Scientific American broke during the preparation of this article, My apologies.