A population of 1000 birds exist on a small pacific island. some of the birds are yellow, a charcteristic dete

Question

a population of 1000 birds exist on a small pacific island. some of the birds are yellow, a charcteristic determined by a recessive allele. the others are green a characteristic determined by the dominante allele. a huricane on the island kills most of the birds from this population. only ten remain and those birds all have yellow feathers. which of the following is true?

A. the hurricane has caused a population bottleneck

B. this situation illustates the founder effect

C. assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds

D. the ten remaining birds will mate only with each other, and this will conribute to gene flow in the population

E. this situation illustrates the principle of adaptive radiation

Answer 1

B. this situation illustrates the founder effect

Answer 2

A  is, i think, the desired answer.  the hurricane has limited the selection of available genes.

one could say that  D  is also true, but that doesn't really relate to the question asked.

one might also say that  B  is true, since the founders of the remaining population have only the recessive gene.

however, it's my suspicion that the answer being looked for is  A.

Answer 3

The only plausible answer is B. A founder effect occurs when a small population has limited opportunities to reproduce with a larger population due to geographic barriers. Since all the yellow birds have to be homozygous recessive, the gene pool has changed. From now on all birds of this species on this island will be yellow.

Actually, while you can make a case of the founder effect, it's really a population bottleneck, A. Sorry about the confusion.

Answer 4

The answer is A

Because the Yellow gene is recessive, only a small part of the population has it. The Yellow birds cannot have the Green gene, so it's completely gone from population. What happens here is that a small population that wouldn't normally be dominant, becomes dominant through a external action, this is known as a population bottleneck, it causes genetic drift.

Taking a look at the answers will rule them out as well.

B - The founder effect is when one group seperates from the main population. This will happen in the future, but it's not the answer.

C - because the Yellow gene is recessive, the birds cannot have the Green gene, or they would be green. This population can not produce a green bird.

D -  Gene flow is the transfer of alleles of genes from one population to another.

E - No, adaptive radiation is a rapid evolutionary radiation of a single, rapidly diversifying lineage

also, it's nice to see an actual question about evolution on here, between all the creationist nonsense.

EDIT:

It is NOT answer B.

If the description has gone on, it would be a founder effect, and a founder effect will occur when the population reproduces but IT IS NOT the answer to this question. Yes, it will occur if the population survives, but it hasn't happened yet. If the description has said: "From now on, all the birds are yellow, what causes this?", the answer would be "B", but that wasn't the question.