Summary
The modern synthesis of evolutionary theory grew out of the cohesion of Darwin’s, Wallace’s, and Mendel’s thoughts on evolution and heredity, along with the more modern study of population genetics. It describes the evolution of populations and species, from small-scale changes among individuals to large-scale changes over paleontological time periods. To understand how organisms evolve, scientists can track populations’ allele frequencies over time. If they differ from generation to generation, scientists can conclude that the population is not in Hardy-Weinberg equilibrium, and is thus evolving.
Glossary
allele frequency
(also, gene frequency) rate at which a specific allele appears within a population
founder effect
event that initiates an allele frequency change in part of the population, which is not typical of the original population
gene pool
all of the alleles carried by all of the individuals in the population
genetic structure
distribution of the different possible genotypes in a population
macroevolution
broader scale evolutionary changes seen over paleontological time
microevolution
changes in a population’s genetic structure
modern synthesis
overarching evolutionary paradigm that took shape by the 1940s and is generally accepted today
population genetics
study of how selective forces change the allele frequencies in a population over time