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Evolution (Speciation (Prezygotic Barriers (block fertilization from…
Evolution
Speciation
is a group of organisms whose members have the potential to interbreed in nature and produce viable, fertile offspring
Reproductive Isolation
the existence of biological factors that impede members of two species from interbreeding and producing viable offspring
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Postzygotic Barriers
ovum is fertilized from another specie and may contribute to reproductive isolation after hybrid zygote is formed
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Polyploidy
specie may originate from an accident during cell division that results in extra sets of chromosomes
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Natural Selection
the process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do other individuals
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selecting and breeding individuals that possess desired traits a process called artificial selection
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natural selection can increase the frequency of adaptations that are favorable in a given enviornment
relative fitness
one organisms has greater relative fitness than another organism if it leaves more fertile descendants
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Genetic Variation
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the nucleotide differences provide the basis of genetic variation that originate when mutations and gene duplication produce new alleles and new genes
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in sexually reproducing organisms, most genetic differences among individuals result in crossing over, the independent assortment of chromosomes, and fertilization
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Gene drift and gene flow
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Gene flow
the transfer of alleles between populations, tends to reduce genetic differences between populations over time