Exam 2 Lecture 9 Life History Evolution Flashcards
(55 cards)
Phenotypic plasticity
= the ability of a single genotype to produce different phenotypes across environments
•Number vs size of offspring
Intrinsic tradeoff (negative correlation)
Semelparous
is characterized by a single reproductive episode before death
Number of eggs laid per Darter clutch is _________ with egg size
negatively correlated
The cost of current reproduction i
s the decrease that current reproduction causes in future reproduction This cost typically decreases with age
•Number vs size of offspring
Intrinsic tradeoff (negative correlation)
r v k: Competitive ability
r v k:
Reproductive effort
the allocation of energy, time, and other resources to the production and care of offspring
Explain Number vs size of offspring
In any given reproductive event, there is a tradeoff between the number of offspring produced and the size of those offspring–Invest in egg yolk, blood supply, provisions
__selection: Characteristic high population growth rate
R selection
—parous: Adult survival is high
Iteroparous
Non-linearity model
If most of the costs of reproduction are realized, even at low levels of reproductive effort, then individuals that invest in a single, massive reproductive event are likely to have a fitness advantage over those that invest in multiple reproductive events
MacArthur and Wilson: r selection
per capita rate of increase
Across many different types of plants, number of seeds per plant
is negatively correlated with average seed size
Define Intrinsic tradeoffs:
- Increase in one life-history trait is linked to a decrease in another life-history trait
- The fitness gains that would have been made by the former are counteracted by the fitness loss caused by the latter •These are usually caused by genetic or phenotypic correlations between life history traits among individuals in a population
Intrinsic tradeoff (negative correlation)
- •Reproduction vs survival
- •Current vs future reproduction
- •Current reproduction vs parental growth
- •Current reproduction vs parental condition
- •Number vs size of offspring
__selection: Most prominent in species whose populations are near the carrying capacity much of the time
K selection
Live Fast Die Young & Neanderthals
‘slow growth’ gave complex brains more time to ‘cook,’ so to speak, and then learn all those things a fancy brain could learn.” “The team noted that the child’s brain had reached only about 87% of an average adult Neanderthal’s brain size, whereas modern human brains reach 90% of their adult size by age 5.
—parity is favored when the ratio of adult:juvenile survival is — or —-
Iteroparity, high or variable
__selection: Strongest in species colonizing new or disturbed habitats.
R selection
•Current reproduction vs parental condition
Intrinsic tradeoff (negative correlation)
—parous: Evolved independently several times
Semelparous
Gene flow between populations of each species
is negatively correlated with egg size
Number of eggs laid per Darter clutch is ________with female size
positively correlated
