Tasmanian Tiger

New Findings from DNA

Tasmanian Tiger: These animals had a huge gape and a powerful bite. In one account a thylacine fighting a dog bit off the top of its opponent's skull.

Old illustration of two thylacines, showing coloration

The thylacine was not a true tiger. Rather it was a marsupial, a pouched mammal like a kangaroo. It had many doglike features. However, it had climbing and leaping abilities far beyond those of a dog. In one old account, an agitated pet thylacine is described as jumping up into the rafters of a cabin and running about there like a cat.

Extensively hunted by farmers, the Tasmanian tiger was already rare in the wild when the National Zoo acquired its specimens. The thylacine was declared extinct in 1936 when the last captive animal died, although numerous unverified sightings are reported even today.

DNA from the preserved National Zoo thylacine family have been studied in recent years. However, high quality sequences could not be obtained. The DNA was simply too contaminated and degraded.

Now, in an approach called "museomics," researchers are returning to the preserved specimens with improved DNA sampling methods and the latest sequencing technology. In the study just published, an international team sequenced both mitochondrial and nuclear DNA from the hair of one of the National Zoo thylacines, a male, and from a female that died at the London Zoo in 1893.

"What I find amazing is that the two specimens are so similar," said Dr. Anders Götherström of Uppsala University in Sweden. "There is very little genetic variation between them." But Götherström, a co-author of the study, noted that this lack of genetic diversity is indeed consistent with the fact that the thylacine was on the verge of extinction. Genetic variation is typically minimal in very small populations.

This study has established the groundwork for more detailed genetic analysis of the thylacine. It also opens the door to more museomic studies using museum specimens worldwide and suggests larger projects of the same sort may be doable in the future. "The large amount of mitochondrial and nuclear DNA gained in our study demonstrates the feasibility of a thylacine genome project," explained Dr. Stephan Schuster of Penn State University, also an author of the report. "It will also revive discussions on the possible resurrection of the animal."