week 2 - parental care

Question 1

define fitness

Answer 1

a measure of the ability of genetic material to perpetuate itself in the course of evolution. it is dependent on the indiviudals ability to survive, the rate of reproduction and the viability of offspring

Question 2

define reproductive success

Answer 2

the passing of genes onto the next generation

Question 3

female reproductive success is limited by what?

Answer 3

offspring number

Question 4

why is sexual reproduction a paradox for evolutionary theory?

Answer 4

because females could reproduce female offspring by parthenogensis but nearly all multicellular species are sexual.

Question 5

Male reproductive success is limited by what?

Answer 5

number of matings

Question 6

What are the advantages of sex?

Answer 6

varied offspring
environment is not static
mutational load
DNA repair

Question 7

Chromosomal sex determination in mammals what are males and females?

Answer 7

XX female

XY male

Question 8

Chromosomal sex determination in butterflies and birds

Answer 8

Females are heterogametic ZW and males are WW

Question 9

Chromosomal sex determinaton produces a ration of how many males:females

Answer 9

50:50

Question 10

In chromosomal sex determination, the assortment of chromosomes during metaphase of meiosis I ensures ????

Answer 10

that exactly half the male gametes contain X chromosomes, and exactly half contain Y.

Question 11

What is environmental sex determination?

Answer 11

sex of an individual is determined by the incubation temperature of the eggs

Question 12

environmental sex determination is seen in which animals?

Answer 12

turtles and alligators

Question 13

what is the function of courtship? (6)

Answer 13

right species
right sex
right time
right place
right conditions
potential for mate assessment

Question 14

Reproduction success should be measured to which generation?

Answer 14

F2

Question 15

What are the problems with trying to determine parents in the field?

Answer 15

we may not observe mating behaviour
if we do observe matings it does not necessarily tell us who the father is
females may have >1 partner
may be multiple paternity in litter

Question 16

What can help us determine paternity?

Answer 16

genetic markers

Question 17

samples for genetic analysis can come from where ? (5)

Answer 17

blood
saliva
tissue
hair roots
faeces

Question 18

what are the 2 mating systems?

Answer 18

monogamy

polygamy

Question 19

within polygamy there are 3 different types

Answer 19

polygyny
polyandry
promiscuity

Question 20

how does the parental care system associate with the mating system?

Answer 20

monogamy - male + female
polygyny - female
polyandry - male
promiscuity - either/neither

Question 21

Mating systems influence ____ ___

Answer 21

sexual selection

Question 22

define polygyny

Answer 22

a type of mating system where one male mates with more than one female while each female mates with only one male. This was once thought to be the fundamental mating system of animals.

Question 23

define polyandry

Answer 23

a type of mating system where females mate with more than one male during a breeding season, resulting in the offspring of one female having more than one father – once thought rare, but now many species known to exhibit multiple mating by females, e.g. tamarins whereas marmosets tend to be monogamous.

Question 24

define promiscuity

Answer 24

a type of mating system where no pair bond is formed. Presumably promiscuous mating systems can evolve where the advantage of the male remaining with the female to help in raising the young is negligible

Question 25

what are the 4 different types of polygyny

Answer 25

Resource defence polygyny
female defence polygyny
lek polygyny
scramble competition polygyny

Question 26

what is resource defence polygyny?

Answer 26

males defend territories that contain resources attractive to females e.g. male back winged damselflies defend aquatic vegetation that the females like to lay eggs in

Question 27

what is female defence polygyny?

Answer 27

males fight with each other to
monopolise females in areas where the latter gather, e.g.
bighorn sheep.

Question 28

what is lek polygyny?

Answer 28

males defend a display area, e.g. black grouse, manikin, topi, fallow deer, cichlids.

Question 29

what is scramble competition polygyny?

Answer 29

males try and outrace rivals

to access receptive females, e.g. thirteen-lined ground squirrels

Question 30

what three things does the polygyny threshold model predict?

Answer 30

1. If differences in quality of male territories influences evolution of polygyny, then it will occur most often in patchy environments when difference in patch quality are marked.
2. Quality of a male’s territory will influence his fitness, in particular the number of females he attracts.
3. Female fitness economics: for females settling at the same time, the fitness of a female who chooses to mate with an already paired male will be at least as great as those who choose an unpaired male.

Question 31

why is there sexual conflict in the polygyny threshold model?

Answer 31

The Threshold model deals with female choice, but males obviously do better if they can sum the offspring of both the 1st and the 2nd female, even though the 2nd female does worse. Therefore, males should try and mate with more than 1 female, as long as the offspring of the 1st female do not suffer as a consequence.
Some males leave 1st female for a short period, mate with a 2nd female, then desert her and return to 1st female

Question 32

why is an understanding of the evolution of parental care critical to the understanding of sexual selection?

Answer 32

because many of the most obvious differences in the reproductive behaviour of males and females are associated with variation in their involvement in parental care.

Question 33

Trivers 1972 defined parental care in terms of parental investment. what is parental investment?

Answer 33

Parental investment is defined as “any investment by the parent in an individual offspring that increases the offspring’s chance of surviving (and hence reproductive success) at the cost of the parent’s ability to invest in other offspring”.

Question 34

Trivers said that relative parental investment of males and females controls which 2 things?

Answer 34

the degree of intra-sexual competition

the degree of intensity of sexual selection.