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23 Cards in this Set

  • Front
  • Back
What is the adaptionist approach?
Whether a particular response is an adaptive product of natural selection.
Define fitness.
Higher reproductive success or higher genetic success
What is fitness benefit?
The positive effect of a trait on the number of surviving offspring produced
What do biologists often have to settle for when they measure fitness?
They often have to settle for an indicator or correlate of reproductive success or genetic success
What defines reproductive success?
The total number of his or her offspring that reach the age of reproduction.
What is the comparative method?
Testing predictions about the evolution of an interesting trait by looking at animals other than the species whose characteristics are under investigation
What is Occam's razor?
The principle of parsimony; holds that simpler explanations are more likely to be correct than complex ones.
Squirrels are less eager to approach speakers playing the rattles of larger and warmer snakes. IN nature, this ability to assess the risk of a snakebite would enable the squirrels to reduce the costs of their mobbing behavior.
What is the benefit of puddling for butterflies?
The dilution effect; any butterfly puddling with fewer than 40 other individuals would decrease its risk of predation.
What do skipper caterpillars do?
Blast their waste pellets 20 body lengths or more from their shelters, because some predators track their prey by odor
What are Darwinian puzzles?
Traits whose costs seem likely to exceed their benefits; seem unlikely to evolve by natural selection
Why do monarch butterflies have brightly colored wings?
Monarch larvae feed on poisonous milkweeds, from which they sequester an extremely potent plant poison in their tissues
Why does the tephritid fly habitually wave its banded wings as if trying to catch the attention of its predators?
Wing markings resemble the legs of jumping spiders, an important fly predator
Which hypothesis of gazelle jumping can be immediately rejected?
The anti-ambush hypothesis, because gazelles feeding in short-grass habitats do stot regularly
What are the 5 hypothesis of gazelle stotting?
1. Anti-ambush: a stotting gazelle sacrifices speed in escaping from one detected predator in order to scan ahead for other as yet unseen enemies lying in ambush
2. Alarm signal hypothesis: stotting might warn conspecifics, particularly offspring, that a predator is dangerously near
3. Social cohesion hypothesis: stotting might enable gazelles to form groups and flee in a coordinated manner, making it harder fora predator to cut any one of them out of the herd.
4. Confusion effect hypothesis: by stotting, individuals in a fleeing herd might confuse and distract a following predator, keeping it from focusing on one animal
5. Pursuit deterrence hypothesis: stoting might announce to a pursuing predator that the individual was in excellent condition and therefore unlikely to be captured, which, if true, would favor predators that stopped chasing that gazelle.
What hypothesis of gazelle spotting is most supported?
Gazelles stot to announce to a predator they will be hard to capture
What do the number of pushups that a lizard does correlate with?
THe lizard's running endurance. ; predators could derive accurate information about the physiological state of a potential prey by watching its pushup performance.
What is the purpose of the correlation between the number of pushups and running endurance in some lizards?
Predators could derive accurate information about the physiological state of a potential prey by watching its pushup performance.
What is the purpose of fear screams?
Caputred animal's screams attract other predators to the scene - predators that may turn the tables on the prey's captor, or at least interfere with it, sometimes enabling the prey to escape in the resulting confusion
What is the optimal theory?
Phenotype X can be considered the optimal trait here, because it is an adaptation; the difference between B and C is greatest for this trait
What is game theory?
Individuals are attempting unconsciously to maximize their reproductive success
What is a selfish herd and how could it hypothetically develop?
Under some conditions, a behavioral strategy that caused individuals to be social could, over time, spread through a population in which the other individuals lived alone. The end result would be a selfish herd, in which all the individuals were trying to hide behind others to reduce the probability of being selected by a predator
What aspect of adaptations does the "selfish herd" theory support?
We define adaptations in terms of their contribution to the fitness of individuals rather than the group