From “Scientists Confirm Limited Genetic Diversity in the Extinct Tasmanian Tiger” (ScienceDaily, Apr. 18, 2012), we learn,
A team of international scientists including from the University of Melbourne have discovered the unique Tasmanian Tiger or thylacine had limited genetic diversity prior to its extinction.
The results revealed the thylacine specimens were more than 99.5 per cent similar over a portion of DNA that is normally highly variable between individual animals.
“If we compare this same section of DNA, the Tasmanian Tiger only averages one DNA difference between individuals, whereas the dog, for example has about 5-6 differences between individuals,” Dr Menzies said.
He said in a direct comparison with other species, the thylacine averages about 5-10 DNA base differences over the coding sections of the mitochondrial genome.
“This is quite low when compared to other species including the wolf (77) or African humans (85).
The tiger was hunted to extinction at the turn of the twentieth century, and the mitochondrial DNA was recovered from museum specimens.
Limited genetic diversity may predispose a life form to extinction because all members of the population may be similarly at risk from a given cause.
Ironically, some research suggests that the marsupial tiger was not even as much of a threat to sheep as farmers feared.
See also: Can biotechnology bring back extinct animals?