What’s the News: Due to a vicious disease, the population of the endangered Tasmanian devil has decreased by at least 70 percent since 1996. The cancer, devil facial tumor disease, spreads when an infected devil bites another, typically during feeding or mating. Because Tasmanian devils are so genetically similar, their bodies don’t recognize the intruding cancer cells as foreign.
But now, researchers have sequenced the genome of two devils and created a genetic test that could help breeders select genetically diverse mates. The test will help conservationists breed future generations of Tasmanian devils that are prepared for the cancer, as well as other types of diseases.
The Tasmanian tiger may have been threatened by inbreeding before humans hunted the marsupial into extinction, a new genetic analysis suggests. The last captive tiger died at a Tasmanian zoo in 1936 after a decades-long effort by farmers and hunters to kill the creatures and collect a government bounty, but the new study suggests that the tigers’ lack of genetic diversity left them particularly vulnerable to the human onslaught and outbreaks of disease. “It’s looking like the thylacines were sort of on their last legs,” says Webb Miller [Science News], one of the coauthors.
Researchers sequenced the mitochondrial DNA of two Tasmanian tigers, more properly known as thylacines, from tissue samples preserved at museums in Sweden and the United States. And while the researchers’ main goal was to investigate the roots of the thylacine’s extinction, they acknowledge that having a complete genome at their disposal is sure to prompt talk of cloning. Says Miller: “Our goal is to learn how to prevent endangered species from going extinct…. I want to learn as much as I can about why large mammals become extinct because all my friends are large mammals,” Professor Miller added. “However, I am expecting that publication of this paper also will reinvigorate discussions about possibly bringing the extinct Tasmanian tiger back to life” [BBC News]. Some scientists think that the thylacine would be one of the easiest extinct animals to resurrect, as it died out recently and several well-preserved specimens exist in museums.