AP Bio Test 9/27

Charles Darwin

proposed that all species of life have descended from a common ancestor

Charles Lyell

demonstrated the power of known natural causes in explaining the earth's history

Jean-Baptiste Lamarck

believed that living things evolved in a continuously upward direction, from dead matter, through simple to more complex forms

Alfred Russel Wallace

believed plants and animals evolved to their environment

Natural Selection

Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success

Homologous Structures

similar physical features in organisms that share a common ancestor, but the features serve completely different functions

Analogous Structures

features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature

Directional Selection

changes in population genetics in which extreme values for a trait are favored over intermediate values

Stabilizing Selection

a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value

Disruptive Selection

changes in population genetics in which extreme values for a trait are favored over intermediate values

Heterozygous Advantage

the case in which the heterozygous genotype has a higher relative fitness than either the homozygous dominant or homozygous recessive genotype

Taxonomy

the branch of science concerned with classification of organisms

Taxonomic Groups

species, genus, family, order, class, phylum, kingdom, domain

Bottleneck Effect

the loss of genetic variation that occurs after outside forces destroy most of a population

Founder Effect

the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population

Genetic Drift

random fluctuations in the numbers of gene variants in a population

Speciation

occurs when a group within a species separates from other members of its species and develops its own unique characteristics

Number of Mass Extinctions

5

Convergent Evolution

process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities

Divergent Evolution

what occurs when two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures

HOX genes

a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals

Coevolution

the influence of closely associated species on each other in their evolution.