Question

how marsupials show adaptive radiation? ​

Answer 1

Answer:

Adaptive radiation is the relativity fast evolution of many species from a single common ancestor.

Answer 2

Answer:

Adaptive radiation is the relatively fast evolution of many species from a single common ancestor. Adaptive radiation generally occurs when an organism enters a new area and different traits affect its survival. An example of adaptive radiation is the development of mammals after the extinction of dinosaurs.

Explanation:

Marsupials in Australia and placental mammals in North America provide another example of conver-

gent evolution. These two subclasses of mammals have adapted in similar ways to a particular food

supply, locomotor skill, or climate. They separated from some common ancestor more than 100 mya,

and each lineage continued to evolve independently. Despite this great temporal and geographical sepa-

ration, marsupials in Australia and placentals in North America have produced varieties of species liv-

ing in similar habitats with similar ways of life. Their resemblances in overall shape, locomotor mode,

and feeding and foraging are superimposed upon different modes of reproduction, the feature that accu-

rately reflects their distinct evolutionary relationships.

Australia, a continent in the southern hemisphere, is the size of North America; 200 mya it was

part of Gondwana, the large southern continent that included Africa, Madagascar, New Zealand,

Antarctica, and South America. As Gondwana split up, Australia became isolated and has remained so

for over 100 million years. Marsupials entered Australia before this separation and have evolved inde-

pendently from placental mammals ever since. Marsupials had a similar and successful radiation in

South America, which was also an island during this same time period. South America joined to North

America as recently as 3 mya, through a land bridge, the Isthmus of Panama. Placental mammals

invaded South America and replaced many marsupial species.

Over 200 species of marsupials live in Australia, along with many fewer species of placentals.

The marsupials have undergone an adaptive radiation to occupy the diversity of habitats in Australia,

just as the placentals have radiated across North America.