Q218 Immigration rates decline as the SIZE of an island decr

Q2.18. Immigration rates decline as the SIZE of an island decreases. (Hint: This wasn\'t directly addressed in the section, but you can use the logic of the equilibrium theory of island biogeography to deduce the answer.)

TrueFalse

Q2.19. Extinction rates decline as the number of species on an island decreases.

TrueFalse

Q2.20. Extinction rates increase as the size of an island increases.

TrueFalse

Q2.21. All else being equal, turnover rates are higher on large islands than on small ones.

TrueFalse

Q2.22. When we think of islands, we often think of them as land masses surrounded by water. Ecologists have suggested a much broader definition of an island. Which of the following would NOT be viewed as an island by an ecologist?

Mountain top habitatsUrban parksCavesThe Sahara desert

Q2.23. Horses originated in North America and then migrated to Asia and Europe. As they migrated, they evolved over many generations into the horse species we see today. This is an example of which migration type?

DiffusionJump DispersalSecular Migration

Q2.24. Horses went extinct in North America and did not return until they were ferried in boats by European settlers (no land mammal can swim on its own across an ocean). From a horse\'s perspective, the ocean barrier is best described as what?

A corridorA filterA sweepstakes route

Q2.25. In the figure to the right, islands A and B are the same size and distance from the mainland. One of them has some smaller islands between it and the mainland. Based on island biogeography, what difference would you expect to see in species richness between A and B, and why?

Island A should have more species than Island B, because Island B\'s extinction rate should be higher.Island B should have more species than Island A, because Island B\'s colonization rate should be higher.Island A should have more species than Island B, because Island A\'s colonization rate should be higher.Island B should have more species than Island A, because Island A\'s extinction rate should be higher.

Solution

Q2. 18. True. Because as per the \"Target effect\", the rate of immigration depends on the size of the Island. If the size of the Island is smaller, then the rate of immigration will be lesser and if the size of the Island is large then the rate of immigration will be much greater.

Q2.19.true. because, if number of species is more, then utilization of nutrients also will be more which causes the extinction of species. If number of species is small, it causes the decline in the rate of extinction.

Q2.20. False. Because there is less extinction if habitat area is more. So with the increase in area, there is decrease in the rate of extinction.

Q2.21.True. Because, turnover rates are more on larger area