Lecture 17- Adaptation Flashcards
what is adaptation?
a change or process of change by which an organism or species becomes better suited to it’s environment
which 2 scientists believed that modification were gradual and not random but were in response to environment?
Lamarck and ERASMUS Darwin
who credited the theories of natural selection?
Charles Darwin
what ideas converged in modern synthesis?
evolutionary biologists (Darwin) and Geneticists (Mendel)
what is Muller’s ratchet?
an accumulation of deleterious mutations (which can be removed by sexual reproduction and recombination)
what promotes adaptation?
anything that gives Natural Selection more to work with in local populations (moderate mutation rate, small gene flow, directional selection)
what prevents adaptation?
inbreeding, genetic drift, large gene flow, stabilizing selection
why are widespread populations more likely to have sub-populations?
different groups experience different environmental conditions that causes differences between organisms eventually creating the sub-populations
what is a fundamental niche?
things an organism COULD be adapted to
what is a realized niche?
things an organism IS adapted to
what are the 2 extremes that aim to explain the speed of evolutionary change?
gradualism and punctuated equilibirum
what is gradualism?
evolution occuring uniformly and by steady/gradual transformation
what is punctuated equilibrium?
evolution being marked by isolated episodes of rapid speciation between long periods of little/no change
what are homologous structures?
similar/ the same adaptations present in organisms with common ancestors (claws on cats and dogs)
what are analogous structures?
adaptations present in species that have no common ancestor (fins on fish, whales, and cuttlefish
