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Flashcards in Chapter 13 Deck (23):
1

Hardy-Weinberg Equilibrium

the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors

2

Homology

the existence of shared ancestry between a pair of structures, or genes, in different species

3

Microevolution

the change in allele frequencies that occur over time within a population

4

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.

5

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

6

Population

The total number of inhabitants constituting a particular race, class, or group in a specified area.

7

Vestigial Structures

A structure in an organism that has lost all or most of its original function in the course of evolution

8

Biogeography

The study of the geographic distribution of species.

9

Bottleneck Effect

Genetic drift resulting from a drastic reduction in population size.

10

Comparative Anatomy

The comparison of body structures in different species.

11

Directional Selection

Natural selection that acts in favor of the individuals at one end of a phenotypic range.

12

Evolution

Decent with modification; genetic change in a population or species over generations; the heritable changes that have produced Earth's diversity of organisms.

13

Evolutionary Adaptation

A population's increase in the frequency of traits suited to the environment.

14

Sexual Selection

A form of natural selection in which individuals with certain characteristics are more likely than other individuals to obtain mates.

15

evolutionary tree

a branching diagram that reflects a hypothesis about evolutionary relationships between groups of organisms

16

fossil record

the ordered sequence of fossils as they appear in the rock layers, marking the passing of geologic time

17

fossils

a preserved imprint or remains of an organism that lived in the past

18

founder effect

the genetic drift resulting from the establishment
of a small, new population whose gene pool differs from that of the parent population

19

gene flow

the gain or loss of alleles from a population by the movement of individuals or gametes into or out of the population

20

gene pool

all the genes in a population at any one time

21

genetic drift

a change in the gene pool of a population due to chance

22

sexual dimorphism

distinction in appearance based on secondary sex characteristics, noticeable differences not directly associated with reproduction or survival

23

stabilizing selection

natural selection that favors intermediate variants by acting against extreme phenotypes