Population Genetics.

1. Genetic _________ that influences the characteristics of organisms provide the raw material for natural selection. 2. Darwin never used the term " evolution " – he used the term " descent ______ __________. " 3. Jean-Baptiste Lamarck proposed that evolution occurred by the _____________ _____________ _____________ _____________. 4. Natural populations contain considerable amounts of genetic variation in all organisms including humans. Such variation cannot be fully accounted by __________ alone. 5. A _________ locus exhibits more variation than is expected by mutation. 6. Migration and hybridization between individuals of adjacent populations causes gene ____. 7. Random changes in the __________ of alleles at a given locus is known as genetic drift. 8. In order to study evolution we must study the properties of genes first within individuals and then within _______________ 9. Genotypes are said to be in _____-_______ equilibrium if there is random mating and no other forces tend to alter the proportions of alleles from one generation to the next. 10. The key point in Darwin's proposal is that the ___________ imposes the conditions that determine the results of selection and thus the direction of selection. 11. The early theory, later disproved, that suggested offspring were always intermediate types relative to their parents, is the theory of _____________ _____________ 12. Selection cannot alter a trait with little or no genetic variation and will not eliminate _________ alleles. 13. Natural selection as a mechanism of evolution that acts on variants within populations and ultimately leads to the evolution of different species was proposed by 14. Features that increase the likelihood of survival and reproduction by an organism in a particular environment are called A. genes B. alleles C. mutations D. adaptations