Midterm 10 Flashcards
(21 cards)
biogeography
new species arise in specific places
paleontology
fossil species record the history of life`
taxonomy
phylogeny; the nested hierarchy of taxonomic classification corresponds to a treelike pattern of similarity among species
homology
common ancestry; species share similarities in a pattern that reflects descent with modification from a common ancestor
the conditions for evolution by natural selection
- phenotypic variation
- heritability
- phenotypic variation is correlated with variation in offspring number
fitness of a trait depends on
how common it is in the population
the Breeder’s Equation
response to selection = selection differential x narrow sense heritability
response to selection = selection differential x narrow sense heritability
response to selection: the shift in the means from one generation to the next
selection differential: the difference in the means between the whole ppl and the selected fraction
narrow-sense heritability: Va/Vp
directional selection
when individuals with traits on one side of the mean in their ppl survive better or reproduce more than those on the other
disruptive selection
extreme values for a trait are favored over intermediate values
stabilizing selection
genetic diversity decreases as the ppl stabilizes on a particular trait value
drift
uniform random sampling
selection
biased random sampling
Darwin Theory
1/ organisms are related by descent from common ancestors
2. natural selection provides an explanation for organismal diversity
convergence
independent origins of similar traits retain signatures of their separate evolutionary histories
evolution by natural selection
phenotypic states that are heritably correlated with higher than average rates of reproduction will increase in frequency from one generation to the next
what happens if cells acquire mutations
- phenotypic variation
- heritability
- reproduce is correlated with phenotype
adaptation
traits that evolved because they increase the fitness of their bearers
evolutionary spandrels
some traits are just side-effects of other traits
constraints on adaptation
some adaptations are compromised by tradeoffs
some conceivable adaptations are inaccessible because of developmental constraints
evolution is shortsighted
fitness landscapes are dynamic
the red queen
evolution of others affects each individual’s relative fitness
- co-evolution of predators and prey; hosts and parasites
