my initial reaction to claims of a placental mammal going extinct in australia due to climate change was that australia doesn't have indigenous placental mammals, and humans must have introduced them.

frankly, i don't want to shed too many tears for dead rats.

but, it turns out that there are two kinds of placental mammals that were introduced to australia before humans, namely bats and a few species of rodents. or, that is the thinking, anyways.

i wonder, though, how a rat would have found it's way from new guinea to australia, short of a land bridge - which, while not entirely outlandish (water levels would have been lower in glacial periods), belies the fact that the continent does not have any other placental species. we have learned the hard way that placentals tend to outcompete marsupials for spaces in the same niches.

so, how did these placentals get there, exactly?

a bat could have flown. granted.

but, maybe we ought to spin this around: is the introduction of placental rodents to australia in the last five million years actually evidence that ergaster made it that far south?

i don't like rats; i mentioned that. but, justice, to me, means keeping australia as a safe homeland for marsupials and monotremes.

placentals out of australia! placentals go home.....

https://en.wikipedia.org/wiki/List_of_rodents_of_Australia#Old_%22Endemics%22_*