An international team of scientists has sequenced the DNA of two extinct Tasmanian "tigers," finding that the two animals were extremely similar to each other with only five differences in 15,492 nucleotides. Their findings suggest that the Australian marsupials, which looked like dogs but were evolutionarily more closely related to kangaroos and koalas, died out about 70 years ago because they may have become too inbred to survive. "Our goal is to learn how to prevent endangered species from going extinct," says co-author Web Miller, in a BBC story.