Question

Occurrence of endemic species in south America and Australia due to :

• A. These species have been extinct from other regions
• B. Continental separation
• C. These is no terrestrial route to these places
• D. Retrogressive evolution

Answer 1

The correct option is B Continental separation

The geographic distribution of organisms on the planet follows patterns that are best explained by evolution in conjunction with the movement of tectonic plates over geological time. Broad groups that evolved before the breakup of the supercontinent Pangea (about 200 million years ago) are distributed worldwide. Groups that evolved since the breakup appear uniquely(endemic) in regions of the planet, such as the unique flora and fauna of northern continents that formed from the supercontinent Laurasia and of the southern continents that formed from the supercontinent Gondwana.
For example, When the ancient landmasses of Laurasia and Gondwana broke apart to form separate continents, the marsupials were divided into two groups. While one group of marsupials was isolated on the Australian island, the other group remained in South America and evolved parallelly.