Adaptation, Life History And Behaviour Flashcards
What is the Lack clutch size observation
Great tits lay 8-9 eggs
What does the Lack clutch size measure?
Number of clutches, and recaptures per brood against clutch size
Reproductive value is another term for
Offspring quality
Offspring survival graph
Offspring survival decreases exponentially post Lack value
Other lack graphs
- Average weight of young against brood number
- Percentage recovered 3 months after feeding against weight
Describe the average weight of young against brood number
- average weight (g)
- as brood number increases, average weight decreases
- strong negative linear correlation
Describe the percentage recovered 3 months after feeding against weight
- weight (g)
- as wight increases, percentage recovered 3 months after feeding increases exponentially
How does the lack value compare to the Lack prediction
Observed: 8-9
Predicted: 8-12
Give another trade off in reproductive success
Current vs future reproduction (multi-generational tradeoff)
Describe mother survival against brood number
As brood number increases, mother survival decreases exponentially after a certain threshold
Describe Visser and Lessells 2001 mother survival test
2 eggs added
What constrains organisms from being ‘Darwinian Demons’?
They have to maximise all aspects of fitness simultaneously (there are multiple fitness axes)
What do tradeoffs arise from?
Limited resources
What is the strategy set of the male redback spider?
To catapult into female mouth or not
What are the competing hypotheses behind the male redback spider observations?
- nutrition to female (nuptial gift of increased resources)
- mating success through assured paternity
Make redback spider female nutrition hypothesis
- disproved
- females lay 250 eggs with or without eating a male
How much bigger are female redback spiders, relative to males
50-100 times
Make redback spider female assured paternity hypothesis
females that have cannibalised their suitor are 67% likely to reject a second suitor, and only 4% if not (Andrade, 1996)
Plotting P2 against CD2 of second male
As copulation duration of second male increases from 11-25 mins, proportion of eggs fertilised increases from 45% (115) to 92% (235)
At what copulation time does non-cannibalisation copulation cease
11 mins
At what copulation time does cannibalisation copulation cease
25mins
Cannibalisation vs future reproduction trade off (Andrade, 2003)
- A cannibalised spider has a 0% chance of reaching another web
- a non-cannibalised spider has a 16% chance of reaching another web
The relative mating success of a cannibalised red back spider is equal to the
- Mating success with the first female
- 235 eggs
The relative mating success of a non-cannibalised red back spider is equal to the
- Mating success with the first female (115)
- chance of making it a o a second female x mating success (0.16x115)
= 133 eggs
- chance of making it a o a second female x mating success (0.16x115)
Bluehead wrasse strategy set
Be a male or a female or a sex changer; when to change
Bluehead wrasse trade off
- Relative benefit of being different sex at different ages
- female fecundity v male mating success
Fecundity against standard length in Bluehead wrasse
- standard length (mm) increases, fecundity increases
- weak linear positive correlation
- R^2 = 0.18
- n = 58
Male size against daily spawning frequency (Warner et al, 1975)
- small fish have 1.3 dsf
- large fish have 43.2 dsf
Plotting of number of female sex changers against number of males removed in Anthias squamipinnis
(Shapiro, 1980)
- As number of males removed increases, number of female sex chambers increases
- strong linear positive correlation
How did Lack calculate great tit reproductive success?
Multiple number of each chick by survival likelihood
Why does offspring quality differ?
- genetics
- metabolic cost involved in raising chicken
What is the cost associated for male red back spiders)
Cannibalisation
What breeding ecology are blue head wrasses?
Harem breeders
Why do some small blue head wrasse males persist?
Sneaky fucker strategy
