Upgrade to remove ads
Terms in this set (27)
Fishers theory 1930
it pays to produce sex that has higher mating success
Fisher 1930, argues the ESS is ?
always beneficial to produce the rarer sex
Mating success per individual = ?
total mating success/ number of that gender (in population)
Lab reared Platyfish
- 3 factor sex determination
- tended to produces a larger number of the sex that is rarest
What must be equal to get an equal sex ratio?
the ratio of success/cost
between males and females
- equal investment between tow sexes
Who showed that in lab reared populations of Platyfish - they tend to produce a larger number of the sex that is rarest?
The sex ratio of males to females should be proportional to?
the costs of producing those sorts of offspring
if very costly to produce females, will see a shift towards producing males who are least costly sex
Despite the hight cost of males in red deer
why is there still equal sex ratios?
might be hard to influence sex ratio, defined by meiosis
might be that females cost more later (e.g. females not dispersing)
Who showed local resource competition in bush babies
who found a small bias in favour of the dispersing sex in primates?
Silk & Brown, 2008
How did Trivers define parental investment?
The reduction in future expected reproductive success due to investment in current offspring
How do African wild dogs show Local resource enhancement?
Males help more in packs
on formation of a new pack, there is a male based sex ratio in offspring production
What Alpine animal shows local resource enhancement?
male biased sex ratio when helpers absent
Hamilton's , 1967 theory concerns?
Extraordinary sex ratios
What do fig wasps show?
local mate competition
What does the Mite Acarophenax show?
local mate competition
Local mate competition occurs when?
it is not the whole population interacting
In Nasonia vitripennis what is shown?
- first female produces female based brood form local mate competition
- second female: detects parasitism already happening and biases sex ratio accordingly
- if laying small clutch - lays male biased
- if laying large clutch - female biased
Mack et al, 2011
Selection experiment - spider mite
1 foundress - 23% males
10 foundress - 45% males
>100 foundress (fisher) - 50% males
Trivers and Hare, 1976 - concerned with?
conflict over sex ratio in reproductives of social hymenoptera
investment in females/investment in males = relatedness asymmetry
- if relatedness asymmetry = 1
= equal investment
If the relatedness asymmetry is 1 then investment between sexes is?
if the relatedness asymmetry of workers goes down, what is predicted?
more equal sex ratios
What evidence is there for more equal sex ratios as relatedness asymmetry of workers goes down?
across 25 species of polygynous ants (>1 queen), investment in daughter is not significant different form 0.5
Boomsma and Grafen suggest?
because colonies differ in relatedness asymmetry
workers have control and known asymmetry in colony
optimal to specialise on one sex
If RA is higher than average in single mated colonies specialise in?
(and vice versa)
When do things deviate from Fishers classic ratio of sex ratios?
when there is local mate competition
there can be conflict over sex ratio if?
Relatedness differs between interested parties
THIS SET IS OFTEN IN FOLDERS WITH...
Size & Fat
Cost of reproduction
YOU MIGHT ALSO LIKE...
Genetics Chapter 4-Sex Determination and Sex-Linke…
Ch. 4: Sex Determination
Sex Linked Inheritance
OTHER SETS BY THIS CREATOR
Senescence, Menopause, Semelparity
Sex Ratios II
OTHER QUIZLET SETS
ECON2013 Final Exam: CH.1,2,3,6,7
chapter 2 business
CH-26: Pulmonary CON'T
Quiz 8 (Ch 8)