In 1983, a population of dark-eyed junco birds became established on the campus of the University of California, San Diego (UCSD), which is located many miles from the junco's normal habitat in the mixed-coniferous temperate forests in the mountains. Juncos have white outer tail feathers that the males display during aggressive interactions and during courtship displays. Males with more white in their tail are more likely to win aggressive interactions, and females prefer to mate with males with more white in their tails. Females have less white in their tails than do males, and display it less often. The UCSD campus male junco population tails were, on average, 36% white, whereas the tails of males from nearby mountain populations averaged 40-45% white. If this observed trait diffe-rence were due to a difference in the original colonizing population, it would most likely be due to:.
a) mutations in the UCSD population.
b) gene flow between populations.
c) a genetic bottleneck.
d) a founder effect.

The answer is D.

Explanation:

The example given in the question is a description of the founder effect which is a term in biology that describes when a small number of the population relocate and this makes an impact on their phenotype compared to the larger population in the original habitat.

The males' relocation has impacted the tail feathers' color and they are now similar to the females which points to a decrease in genetic variation.

I hope this answer helps.

The correct option is option D.

Explanation:

The founder effect is termed as the reduction in the genetic dispersion among the specie due to the travel/shift of specific population, a new population is formulated.

The option A is not correct as the mutations are less likely to occur in this case.

The option B is not correct as the two populations were at different places which were miles apart.

The option C is not correct as the white color in the tail was an effective component in companion selection

so the only correct option is option D.

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

correct answer is a. and d.