mating systems and parental care Flashcards
(26 cards)
what is anisogamy and what ae the usual priorities
fertilisation involving two dissimilar gametes. it affects parental investment where males often prioritise mating whilst females prioritise parenting
what governs polygamy and when is it most prevelent
it is governed by resource availability and synchrony of females being available to mate. it is most prevalent with clumped resources and total asynchrony
what are the key messages from the polygyny threshold model
that in low quality territory polygamous individuals are at a large disadvantage whereas in high quality territory there isn’t much difference between polygamous and monogamous. the better territory compensates for the resources lost due to polygamy
what are the benefits of polyandry (5)
ensures good genes, ensures genetic complementarity, additional parenting, reduces infanticide and can increase female reproduction if she can leave offspring with male and go mate again
what is sex reversal
an occurrence under extreme polyandry where females compete for males to the extent that their morphology is changes
what are preferred mating systems for different sexes and when does each prevail
males prefer polygyny and females prefer polyandry. which sex ‘wins’ depends on resource distribution and individual competitiveness, and if neither win there is polygynandry
what is the female enforced hypothesis
monogamy is due to females aggressively deterring males from approaching other mates
what is the parental care hypothesis
monogamy is due to both sexes benefitting from the males helping rear offspring rather than siring more
what is a lek
males gather at display sites and females visit there to mate. they are only for mating and there are no other advantages for either sex
what are the two types of lek
hotspots (where females would be anyway eg for food) or hotshots (gathering around a particularly attractive male in the hopes that it will attract more females)
what are the benefits of leks (2)
they decrease risk of predation and increase signal attractiveness due to complexity and size
what is the lek paradox
why is there variation when there is choice and the females would all choose the highest quality? must be due to fluctuation of environmental factors so the ‘optimum’ is constantly changing, thus replenishing genetic variation
what are the three types of parental care
uniparental (usually fish and amphibians), biparental (usually birds) and none
what does the parental care depend on (3)
paternity confidence, order of gamete release and proximity association when care is needed
when does male-only care happen
when caring is more costly to the female then the male- interspawn interval
what is parental investment
investing in offspring to increase their chance of survival at the cost of other offspring or to themselves (mating opportunities and survival)
what is parent offspring conflict
conflict of when parents should stop caring for offspring. offspring want more than 1/n of the care, but now all of it due to inclusive fitness
what is cooperative breeding
adults who are physiologically capable of breeding don’t and instead provide care for offspring of others
what is cooperative breeding
adults who are physiologically capable of breeding don’t and instead provide care for offspring of others
in cooperative breeding why don’t some adults breed
ecological constraints and the numerous advantages of group living
in cooperative breeding why do adults care for others (6)
instinct, practice to increase later fecundity, survival, sneaky mating, recruiting offspring to take over territories and inclusive fitness (preference shown for caring for closer relatives)
what is eusociality and what are the requirements to be classed as this
extreme cooperative behaviour. it needs to overlap generations, show parental care in a permanent nest and have distribution of labour (often resulting in caste polymorphism)
why don’t workers reproduce in eusociality
due to ecological constraints, inclusive fitness (especially in haplodiploid species) and parental manipulation (especially in diploid species)
what is anarchy
workers in eusocial systems reproduce. it’s most common when the dominant female mates polyandrously
