Biology . 7 questions?
1.what is genetic drift?
a. the production of an evolutionarily independent group of organisms
b. the motion of continental plates over time
c. the physical splitting of a habitat
d. a change in allele frequencies caused by random events 2.why are the large finches now living on the galápagos islands different from the original source population from a nearby island?
a. natural selection favored individuals that were more fit in the new environment.
b. all three answers are correct.
c. the separation of habitats reduced gene flow between the populations.
d. genetic drift occurred in the two populations. 3. true or false? the last ice age produced many different species mainly because populations dispersed and colonized new habitats.
a. true
b. false 4. which of the following statements about reinforcement is true?
a. reinforcement increases the number of intermediate phenotypes.
b. reinforcement is a type of natural selection.
c. reinforcement decreases the morphological difference between two incipient species.
d. reinforcement is also called dispersive selection 5.a subset of a population of birds leaves its habitat on the mainland and colonizes a nearby island. the birds, after a period of time, become reproductively isolated. the island sinks and the population of birds that lived on the island returns to its original habitat. which of the following statements about these bird populations is true?
a. the populations will not be able to interbreed because they are different species.
b. the populations will be able to interbreed even though they are different species.
c. the birds were separated by a vicariance event.
d. the populations were sympatric while they diverged. 6.a population of birds colonizes an area in which the insects upon which they feed live inside trees. which of the following events accounts for an observed increase in average beak size in the bird population over time?
a. decreased fitness of the insects, allowing the birds to catch them more easily
b. decreased fitness of small-beaked birds, creating a new species
c. ncreased fitness of the large-beaked birds, creating a new species
d. ncreased fitness of large-beaked birds, leading to natural selection 7. true or false? a flood that separates a population of frogs onto opposite sides of a lake is an example of a vicariance event that may result in allopatric speciation
a. true
b. false