According to new research and mathematical modeling, Tasmania's marsupial "tiger" might hvae been on a path to extinction before it even met humans. But once the two species did meet, the ending was grimly predictable.
The thylacine was already set up for trouble in the long run by low genetic diversity. That itself is survivable: the cheetah has the same problem. But when humans put bounties on it, converted prime habitat to sheep farms, and wiped out its prey species (a factor not much taken into account by earlier studies - I'd never thought about it), the modeling shows it had nowhere to go but down. A distemper-like disease was suspected because of how fast the "tiger" slid into extinction, with the last definite specimen dying in a zoo in 1936. But apparently, we needed no help from microbes.
COMMENT: Cryptozoologists still look for this animal, and a trickle of sightings in Tasmania, on the Australian mainland, and in New Guinea give some reason to keep looking. But while the animal definitely survived past 1936 - I think the evidence is very solid on that - its current chances, while not zero, are tragically small.