Ques. 1AIPMT 2001
Occurrence of endemic species in South America and Australia is due to
- There is no terrestrial route to these places
- Retrogressive evolution
- These species have become extinct from other regions
- Continental separation
Answer
(4) Continental separation
Solution
As per NCERT, when South America joined North America, the mammals of the north overrode the South American fauna; similarly, due to continental drift, Australian pouched mammals survived because of lack of competition from other mammals.
⇒ After the separation of the continents, the isolated populations evolved independently and gave rise to species found only there (endemic species).
∴ Endemic species of South America and Australia are due to continental separation.
Answer: (4)