When does geographic isolation occur?
1 Answer
Geographic isolation may occur due to separation by accident/catastrophe. It may also occur due to migration and isolation.
I would request you to read this as well.
Explanation:
We will discuss some examples of geographic isolation to understand this.
- Geographic Isolation due to continental drift :
Each of North American continent and South American continent became an isolated land mass when Pangaea completely disintegrated. About 65 million years ago, coenozoic era began and life on the two American continents were evolving in separate directions. This is why North American continent never had monkeys or sloth.
The story changed about 13 million years ago, when an isthmus appeared between the two continents. Though it allowed extensive migration of land flora and fauna, it stopped all interbreeding between aquatic organisms living on the two sides of isthmus.
(
)
- Geographic Isolation due to distance:
Lions are today living mainly in Africa and only few hudred of them are located in Gir forest of India, on its western front (a small red dot on the map). The species was once distributed in all the intervening areas but hunting and habitat fragmentation has geographically isolated the African and Asian lions.
(
)
- Geographic Isolation due to migration:
Accidental migration of few finch birds in volcanic islands of Galapagos , geographically isolated the small group from original south American population. Geographic isolation always acts in favor of reproductive isolation and evolution.
(
)
Geographic Isolation helps in promotion of adaptive radiation and allopatric speciaton .
