Question

Australian marsupials and placental mammals are suitable examples of adaptive radiation and convergent evolution. Explain giving reasons.

Answer 1

Hint: The process of change of characteristics of a species over an extended period is referred to as evolution. The process of evolution is based on the number of generations and the procedure of natural selection.

Complete answer:
Adaptive radiation is a process in evolutionary biology in which organisms rapidly diversify from an ancestral species into a plethora of new forms, particularly when a change in the environment makes new resources accessible, introduces new challenges, or creates new environmental niches. The evolution of various Australian Marsupials from a single ancestral stock in the Australian subcontinent is an example of adaptive radiation. This describes the divergent evolution of the ancestral stock, which gives rise to a variety of species. Convergent evolution occurs when multiple adaptive radiations for different organisms occur in a given geographical region. Convergent evolution is the mechanism by which species that are not closely related (not monophyletic) evolve together. When species start different and then become more similar, this is known as convergent evolution. Convergent evolution can be seen in Australia's marsupials and North America's placental mammals. These two subclasses of mammals have adapted to a specific food source, locomotor ability, or environment in similar ways. They split from a common ancestor more than 100 million years ago, and due to convergent evolution, each lineage continued to evolve independently.

Note:
Charles Darwin is known as the “father of genetics”. He defined evolution as the “descent of modification” and defined it as the idea that species change over time and give rise to new species that share a common ancestor. He proposed the theory of evolution based on “Natural Selection”.