reminants or remains of organisms that lived long ago
fossiles
body parts that are similar in structure but may differ in functionality
Homologous Structures
Study of developmet from embryo to adult hood
comparative embryology
comparing bodily fluids like hemoglobin or blood
Molecular biology or biochemistry
comparing where an organism lives or where it's ancestors lived
biogeography
comparing body structures like jaws, skulls, teeth and bones
comparative anatomy
humans choosing desirable traits of domesticated organisms to breed
selective breeding or artificial selection
the entire collection of alleles or genes among a population at any one time
gene pool
small-scale changes in allele frequencies over generations of time
MICROevolution
3 things that can cause genetic variation in organisms that reproduce sexually
independent assortment, crossing over, random fertilization
sexual repro alone will not change the gene pool without other factors operating
Hardy-Weinberg equilibrium
p^2 represents
Frequency of homozygous dominants
2 pq represents
Frequency of heterozygotes
q^2 represents
Frequency of Homozygous recessives
define an organisms "fitness"
the contribution the individual makes to the gene pool of the next generation relative to other individuals
3 main causes of evolutionary change within microevolution
natural selection
genetic drift
gene flow
when the genetic make up of a small icolated population is not likely to be the same as the original population
bottleneck effect
a cause of genetic drift attributable to colonization individuals from a parent population
founder effect
the type of environmental impact that favors intermediate phenotypes in relatively stable environments
Stabilizing selection
this type of selection shifts the overall make up of the population by acting against individuals at one of the phenotypic extremes. Most common during periods of environmental change or when individuals migrate to new habitats with different conditions
Directional selection
environmental conditions are varied in a way that favors both the extremes in phenotypic expression