mating systems and parental care

Question 1

what is anisogamy and what ae the usual priorities

Answer 1

fertilisation involving two dissimilar gametes. it affects parental investment where males often prioritise mating whilst females prioritise parenting

Question 2

what governs polygamy and when is it most prevelent

Answer 2

it is governed by resource availability and synchrony of females being available to mate. it is most prevalent with clumped resources and total asynchrony

Question 3

what are the key messages from the polygyny threshold model

Answer 3

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

Question 4

what are the benefits of polyandry (5)

Answer 4

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

Question 5

what is sex reversal

Answer 5

an occurrence under extreme polyandry where females compete for males to the extent that their morphology is changes

Question 6

what are preferred mating systems for different sexes and when does each prevail

Answer 6

males prefer polygyny and females prefer polyandry. which sex ‘wins’ depends on resource distribution and individual competitiveness, and if neither win there is polygynandry

Question 7

what is the female enforced hypothesis

Answer 7

monogamy is due to females aggressively deterring males from approaching other mates

Question 8

what is the parental care hypothesis

Answer 8

monogamy is due to both sexes benefitting from the males helping rear offspring rather than siring more

Question 9

what is a lek

Answer 9

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

Question 10

what are the two types of lek

Answer 10

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)

Question 11

what are the benefits of leks (2)

Answer 11

they decrease risk of predation and increase signal attractiveness due to complexity and size

Question 12

what is the lek paradox

Answer 12

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

Question 13

what are the three types of parental care

Answer 13

uniparental (usually fish and amphibians), biparental (usually birds) and none

Question 14

what does the parental care depend on (3)

Answer 14

paternity confidence, order of gamete release and proximity association when care is needed

Question 15

when does male-only care happen

Answer 15

when caring is more costly to the female then the male- interspawn interval

Question 16

what is parental investment

Answer 16

investing in offspring to increase their chance of survival at the cost of other offspring or to themselves (mating opportunities and survival)

Question 17

what is parent offspring conflict

Answer 17

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

Question 18

what is cooperative breeding

Answer 18

adults who are physiologically capable of breeding don’t and instead provide care for offspring of others

Question 19

what is cooperative breeding

Answer 19

adults who are physiologically capable of breeding don’t and instead provide care for offspring of others

Question 20

in cooperative breeding why don’t some adults breed

Answer 20

ecological constraints and the numerous advantages of group living

Question 21

in cooperative breeding why do adults care for others (6)

Answer 21

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)

Question 22

what is eusociality and what are the requirements to be classed as this

Answer 22

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)

Question 23

why don’t workers reproduce in eusociality

Answer 23

due to ecological constraints, inclusive fitness (especially in haplodiploid species) and parental manipulation (especially in diploid species)

Question 24

what is anarchy

Answer 24

workers in eusocial systems reproduce. it’s most common when the dominant female mates polyandrously

Question 25

what is the concorde fallacy

Answer 25

investing in something endlessly because you don’t want to waste previous investments in it

Question 26

what is asynchronous hatching

Answer 26

having eggs that hatch at different times, promoting sibling competition and conflict. if resources are sparse the youngest will die in order to prioritise the older, stronger offspring