4 ms·
> Think of marsupial/mammal convergence. Is it really wrong to think of marsupial mice and mammalian mice as a somehow similar kind of thing? It seems to me th
by ashtonbaker 5y ago
> Think of marsupial/mammal convergence. Is it really wrong to think of marsupial mice and mammalian mice as a somehow similar kind of thing?
It seems to me that most of the similarity can be explained by their shared phylogenetic history. Before the K-T extinction, that ecological niche was probably occupied by a very different small animal, and its occupation of that niche may have even been quite stable. So, occupation of a particular niche by an organism doesn't really imply optimization over the space of possible organisms, but rather over the space of relatively cheap modifications to existing body plans.
Think of it this way - say Australia had never been connected to the rest of the continents, so no organism with a common ancestor with mammals could exist there. How similar would the organisms filling the niche of marsupial mice be then? Probably some strategic similarities like burrowing etc, but probably enough to pass as a pseudo-mammal.
- thaumasiotes 5y ago> Think of it this way - say Australia had never been connected to the rest of the continents, so no organism with a common ancestor with mammals could exist there. This was more or less true of New Zealand until the 13th century. The only indigenous mammals were bats.