Why the evolution speed of Australian mammals has been low?

Question

(Australian mammals are in marsupials' stage and have not reached to evolution stage of advanced mammals yet.)

Answer 1

The speed of evolution in Australia has been no less than the speed elsewhere. Separation of Australia and its marsupials from the developing placental mammals of Asia meant that evolution took diferent pathways. The placental mammals evolved eleswhere but very few marsupials did. The range and diversity of marsupial evolution is well shown by the fossils coming out of Riversleigh north of Mt Isa in western Queensland.

A fossil of a placental mammal as old as the earliest marsupial fossils has been found in Australia but it was obviously unsuccessful and did not survive where the marsupials did.

Marsupials amd placental mammals have a common ancestor but marsupials do not evolve into placentals. They are very successful as they are.

Rodents, placental mammals, arrived in Australia about 15 million years ago. These evolved into 47 species of rats and mice. Another rodent arrived about a million years ago which evolved into seven species known as the "New endemics".

Australia has another large group of placental mammals, the bats. many of these have evolved here and are found nowhere else.

Answer 2

Australian mammals have evolved just as fast as other continents mammals and continue to do so. Marsupials are no less advanced than other mammals and have evolved highly specifically to the different environmental conditions they are faced with.

Advanced mammals lost in the evolutionary race with marsupials in Australia due to many varying reasons and it is only now due to human introductions placental mammals exist in Australia.

Marsupials have evolved as much as other animal groups and some species have managed to re-invade other lands (e.g possums) where evolutionary pressures will no doubt cause further changes from there Australian cousins.

Answer 3

Au contraire:

The marsupials evolved very quickly. From one root stock, they branched out to cover all the niches covered by many different orders of mammals in other parts of the world. The idea of regular mammals being higher somehow (and people being higher still) is a misconception. Evolution merely selects animals that are suited to their environment. The marsupial's ancestor caught a huge break by being isolated from the rest of the mammals, so they got to evolve to fill all kinds of roles.

Answer 4

You don't understand evolution.

First of all the very concept of 'evolution speed' is a very poor idea and thats why you dont find it in any books on evolution.

Advanced mammals - so mammals with nipples are more advanced - lol, truly our teats make us god unto lesser creatures... how silly.

Aren't sharks advanced? They're incredibly well-adapted hunting and killing machines. Evolution says if its not broken, then don't fix it.

Marsupials have evolved very well - look at the hopping bodytype - everything from the giant red kangaroo to tree kangaroos and hopping marsupial mice. Doesn't that count for something?

Answer 5

Placental mammals evolved once. Australia was isolated before the adaptation developed. It is not a "stage". It is one solution to the problem of bearing live young. It is not as efficient as a placenta, but in the absence of placental mammals, it is good enough. Besides, if it were more than a slight advantage, oppossums would not have survived on other continents.

Answer 6

i assume it may be by using a potential of eggs that slowly grew to become weaker and much less significant. eggs that hatched extra and extra at as quickly as, till a element the place the hatching surpassed off distinctly much quickly, and at last there became no egg. Shane - it certainly relies upon on the ambience. it incredibly is tough to have self belief that Ice and steam the two began as water, however the ambience has a tremendous result. upload some million years and a few million environmental transformations, and something can ensue. look at brief time era evolutionary effects; The inhabitants of wealthy international locations are starting to be to be taller and taller, the kind of blond haired people is lowering, people are researching to communicate at youthful an prolonged time, hypersensitive reactions are coming up left suitable and centre. Evolution is taking place suitable formerly your very eyes, on your person lifetime - how are you able to even start to think of the results of thousands and thousands of years of organic decision??

Answer 7

I would think that one reason would be the relative isolation of Australia. It isn't connected to other large land masses. Having limited environmental factors to promote evolutionary pressures could account for this in part.

Answer 8

Isolated population and low genetic diversity.

Answer 9

isolation, not a lot of predator