Concept 23

Concept 23 - phenotypes resulting from their interactions...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Concept 23.3 Natural selection, genetic drift, and gene flow can alter frequencies in a population. Genetic Drift - Statistically, the smaller a sample the greater the chance of deviation from a predicted result - With small population sixes, allele frequencies can fluctuate unpredictably from one generation to the next - Tends to reduce genetic variation Gene Flow - Genetic additions to or subtractions from a population resulting from the movement of fertile individuals or gametes - Migration among populations - Tends to reduce variation among populations over time Concept 23.4 Natural Selection is the only mechanism that consistently causes adaptive evolution - Natural selection: differential success in the reproduction of different
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: phenotypes resulting from their interactions with the environment. Evolutionary Fitness-Fitness: the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals Sexual Selection-Type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate-Can result in sexual dimorphism-Intrasexual selection: direct competition among individuals of one sex for mates of the opposite sex-Intersexual selection: individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex...
View Full Document

This note was uploaded on 03/27/2010 for the course BIOL 1202 taught by Professor Gregg during the Spring '08 term at LSU.

Ask a homework question - tutors are online