Question

Island bio geography theory states that the number of species on an island is determined by immigration rates of new species to the island and extinction rates of species on the island immigration rates to an island decline as its distance froooom the mainland increases and extinction rates decrease with increasing island size when the immigration and extinction rates on an island are equal, the number of species on the island reaches equilibrium.
Which of the following gives the correct combination oof distance (near and far) and area (small and rage )of island where species (s-s) occur?

• A. $S_1$ - near island, small island
• B. $S_2$ - near island, large island
• C. $S_3$ - near island, far island
• D. $S_4$ - near island, large island

Answer 1

The correct option is D $S_4$ - near island, large island

If the island is near the mainland, a number of species will reach the island. So, the competition between them will increase. As the distance of the island from the mainland increases, the immigration rate will also decrease.

So, option D is the correct answer.