 The science of genetic change in populations.  Population- interbreeding single-species group  individuals of the same species, living in the same place at the same time  Populations are the smallest unit that can evolve.

 As a change in the prevalence of certain traits in a population over several generations  Evolution is only apparent when a population is tracked over time

 Spontaneous mutations may produce new traits  Segregation & independent assortment produce variations in gametes & offspring  Genes are passed through gametes from parents to offspring

 Theory developed in the 1940’s  Includes genetics and evolution

GGENE POOL = where all members of the next generation get their genes! WWhen allele frequencies in a population change over generations, evolution is occurring at its smallest scale.

 Species distributed over a geographic range –> have different gene pool  THAN  Species localized  due to water, islands, mountains etc.!!!

 1. genetic drift  2. bottleneck effect  3. founder effect  4. gene flow  5. mutation

 A change in the gene pool of a small population due to chance!  Ex: flipping coin 10X

 Type of genetic drift - colonization of a new location by a small number of individuals  small size, less representative of the gene pool.

 Fertile individuals move into or out of a population  Gametes are transferred between populations.

 Allele frequency with ONLY sexual reproduction involved!  NO OUTSIDE AGENTS

p = dominant q = recessive 2pq = heterozygous p + q = 1 p 2 + 2pq + q 2 = 1

 1. very large population  2. population is isolated  3. mutations (changes in genes) do not alter the gene pool

44. mating is random 55. all indiv. Are equal in reproductive success  NO NATURAL SELECTION OCCURS!

 Conditions rarely met by a natural population  Gives us a basis to compare nonevolving population vs. actual ones with gene pools that are changing!