Chapter 13 Flashcards
Hardy-Weinberg Equilibrium
the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors
Homology
the existence of shared ancestry between a pair of structures, or genes, in different species
Microevolution
the change in allele frequencies that occur over time within a population
Modern Synthesis
a consolidation of the results of various lines of investigation from the 1920s through the 1950s that supported and reconciled the Darwinian theory of evolution and the Mendelian laws of inheritance in terms of natural selection acting on genetic variation.
Natural Selection
any characteristic of an individual that allows it to survive to produce more offspring will eventually appear in every individual of the species
Population
The total number of inhabitants constituting a particular race, class, or group in a specified area.
Vestigial Structures
A structure in an organism that has lost all or most of its original function in the course of evolution
Biogeography
The study of the geographic distribution of species.
Bottleneck Effect
Genetic drift resulting from a drastic reduction in population size.
Comparative Anatomy
The comparison of body structures in different species.
Directional Selection
Natural selection that acts in favor of the individuals at one end of a phenotypic range.
Evolution
Decent with modification; genetic change in a population or species over generations; the heritable changes that have produced Earth’s diversity of organisms.
Evolutionary Adaptation
A population’s increase in the frequency of traits suited to the environment.
Sexual Selection
A form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates.
evolutionary tree
a branching diagram that reflects a hypothesis about evolutionary relationships between groups of organisms
fossil record
the ordered sequence of fossils as they appear in the rock layers, marking the passing of geologic time
fossils
a preserved imprint or remains of an organism that lived in the past
founder effect
the genetic drift resulting from the establishment
of a small, new population whose gene pool differs from that of the parent population
gene flow
the gain or loss of alleles from a population by the movement of individuals or gametes into or out of the population
gene pool
all the genes in a population at any one time
genetic drift
a change in the gene pool of a population due to chance
sexual dimorphism
distinction in appearance based on secondary sex characteristics, noticeable differences not directly associated with reproduction or survival
stabilizing selection
natural selection that favors intermediate variants by acting against extreme phenotypes
