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Unformatted text preview: 1. What is natural selection?-- The survival of the fittest. Acts on traits that benefit the adaptation of the species to their environment.-- The Theory of Evolution by Natural Selection formulated by Charles Darwin published “The origin of Species” in 1859-- Evolution by means of natural selection was for Darwin and Wallace just the differential reproductive success of the species and the adaptation to changing environments where adaptive characters are perpetuated and non-adaptive ones are eliminated 2. What are the basic postulates of evolution by means of natural selection? 1. The ability of a population to expand is infinite, while the resources available to sustain the population are finite. This dynamic causes a struggle for existence among individuals as they compete for resources. 2. Organisms vary in their physical qualities; these variations allow some members to survive and reproduce more successfully than others producing more offspring in the same environment. 3. These variations are inherited by offspring from their parents. Thus traits that confer advantage in survival and reproduction are retained in the population, and traits that are disadvantageous disappear. 3. Where does natural selection operate?-- Adaptation operates at the level of individuals who compete for resources and reproductive success. This is also important when we look at individual decision-making in terms of cultural adaptation--Selection produces adaptations that favor individuals, not populations or species--Adaptation favors the “fitness” of the individual 4. What is fitness?--Fitness: is the reproductive success of an individual. In other words, it is the number of offspring that an individual has.--Selection produces adaptations that favor individuals, not populations or species--Adaptation favors the “fitness of individuals”--Fecundity is the ability to produce offspring--Continuous Variation is the accumulation and random selection of traits that produce adaptive changes and the evolution of species--Natural selection can only work if each small change along the way is itself adaptive 5. Why did the variation in skin color evolve?...
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- Spring '11