Ecology Lecture Test (2)b

Pair bond between individuals

Time. It is defined as a pair bond between individuals, but how long does that bond have to last? One season? For life?

• Both parents could be required to be able to successfully raise young.
• Partners can share learned experiences, and don't have to deal with a novice.

a single member of one sex bonds with several members of the other sex

polygyny

One male with several females. Females benefit because the strongest male wins the harem, therefore the offspring have a genetically more fit father: this means the females offspring are more likely to survive.

• hairless, burrowing rodent from Africa
• only one female breeds, but if she dies another replaces her
• caring for young is cooperative but only between breeding female nurses

When establishing a eusocial society, a species must be able to populate castes. Termites accomplish this task in a preordained fashion using a haplodiploid characteristic to distinguish castes. In naked mole rats however, there is not a haplodiploid system. Instead they rely on hormaonl signaling to populate their castes, thus estabolishing the eusocial type society. Not sure if this is true. It's my interpretation.

Breeding naked mole rat females leave a chemical which inhibits other females, until she dies and another becomes the breeder.

sex role reversal: one female has several males, seen in a few birds

A male builds a nest to attract female, she picks the best. Who raises babies? If it only takes one, who gets to leave? The male has more invested in the nest than the female does in the egg.

"one night stand", meet, copulate, depart (no continuing bond relationship)

• It takes two to raise child. Don't want novice.
• Only takes one to raise child. Male has more invested in nest.
• Female wants strongest male for his genes and protection.
• Only takes one to raise child. Male has no investment. Can leave.

promiscuous

The female can get enough food to feed self and young (i.e., the male isn't needed.)

the male can leave because the child would be cared for, the female might think less about the future because the state or legal system would insure that the child is cared for

Yes, according to Dr. T.

Habitats and environment. The environments sets the standards. A monogomistic bird might choose a polygyistic relationship if the environment is better. Remember the graph.

It is measured by the relative number of grandoffspring.

if habitat quality within the breeding area is quite variable, females may choose to become polygynous rather than monogamous.

• males want to mate with anything of the same species if they can, this means potentially more offspring carrying their genes
• females are more selective, they are limited in the number of offspring they can produce to carry their genes so they want the best genes possible in the father.

In general a female wants the greatest fitness possible, so if a male can defend a territory enough better than another male's territory (which is unmated) she may give up the opportunity to be monogamous for fitness in the mated male.

essentially adultery in human terms, it is when a female mated to one male mates also with another male.

It reduces a female birds chances of mating with an infertile male. A bird doesn't know if the egg she is incubating is sterile (unfertilized).

change; descent with modification

genes that produce advantageous phenotypes gradually are expressed commonly in populations through successive generations. Thus, this 'gradual change' or shift in allele frequency via natural selection through successive generations portrays evolution.

There ~might~ be something on the test.