204,165 views
14 votes
14 votes
In order to attract females, the male Bowerbird of Australia constructs elaborate structures called "bowers" on the forest floor. His bower is made from twigs, leaves, and moss, and is decorated with colorful ornaments such as feathers, pebbles, berries, and shells. If a female is sufficiently impressed with a bower, she will mate with the male who built it. This is an example of which of the five evolutionary forces? mutation gene flow non-random mating genetic drift

User Soojin
by
3.4k points

1 Answer

25 votes
25 votes

Answer:

non-random mating

Step-by-step explanation:

In animals, most cases of non-random matings are related to behavior. There are three main possible ways of non-random mating:

  • Harem reproduction ⇒ Dominant males mate with their group of females
  • Discriminated mating ⇒ Individuals mate with genetically similar partners
  • Sexual selection ⇒ One of the couple members chooses the other one.

Sexual selection

In many bird and mammal species, and even in some fish species, one of the sexes selects the other one to mate. In general, the one that chooses is the female.

Intrasexual competition between males to get access to females plays a significant role in sexual selection. Males can develop weapons that make them greater fighters.

There is also intersexual selection, in which members of each sex apply selective pressures on the other sex, modeling their phenotype by choosing partners.

As notorious structures and behavior make males be more vulnerable to predation, sexual selection seems to operate against other types of natural selection, as it might affect males´ survival.

However, there seems to be a compensation between sexual selection and natural selection.

----------------------------------------------------------------------------------------------------------

In the exposed example, the construction of elaborated and noticeable structures is done to attract females. If females are impressed with a bower, she will choose the male that built it to mate. The better the nest is, the better the male genetic quality. So the female chooses this male because his genetic charge is significant and reflects a higher fitness for their progeny.

User Yet Another Geek
by
2.8k points