Question

question 7
islands provide ideal opportunities to study speciation because:
a they have small land areas that make it relatively easy to monitor their populations.
b organisms cannot easily move off of islands.
c few organisms can cross long distances across oceans to reach isolated islands.
d all of these are correct

question 8
which population would have the most loss of diversity from a genetic bottleneck?
a 100 elephants
b 1000 mice
c 103 e. coli
d 10 cats
e 100 humans

Explanation:

Question 7

• Option A: Small land areas do make population monitoring easier, which is useful for studying speciation as we can track changes in populations more effectively.
• Option B: If organisms cannot easily move off islands, it helps in maintaining relatively isolated populations. Isolation is a key factor in speciation (e.g., allopatric speciation where a physical barrier isolates a population).
• Option C: Few organisms crossing long - distance oceans to reach isolated islands means that the initial colonizers can then undergo speciation in isolation. For example, Darwin's finches on the Galapagos Islands likely had a few ancestors that reached the islands and then diversified.

Since all of these factors (ease of population monitoring, limited emigration, and limited immigration) contribute to islands being ideal for studying speciation.

A genetic bottleneck is an event that drastically reduces the size of a population. The smaller the original population size, the more likely it is to lose genetic diversity. Among the given options:

• Option A (100 elephants): Larger than the population in option D.
• Option B (1000 mice): Larger population size compared to option D.
• Option C (103 E. coli): While E. coli has a large potential for rapid reproduction, in terms of the initial population size given (103), it is larger than 10.
• Option D (10 cats): Has the smallest population size among the options. A smaller population has less genetic variation to begin with, and a bottleneck (which further reduces population size) will have a more severe impact on losing the already limited genetic diversity.
• Option E (100 humans): Larger than the population in option D.

Answer:

D. all of these are correct

Question 8