Lesson 3 Flashcards
Population
organisms of the same species that live in a particular geographical area at the same time
capable of interbreeding
Population genetics
study of diversity in terms of allele differences
look at genotype and phenotype frequencies over time
microevolution
evolutionary changes within a population
gene pool
all the alleles of all the genes of all individuals in a population
gene pools can be described in terms of
allele frequencies
allele frequency
the proportion of each allele within a gene pool
frequency of dominant and recessive alleles must add to
1
Causes of microevolution
genetic mutations
gene flow
genetic drift- bottleneck effect, founder effect
non-random mating
genetic mutations
lead to evolutionary change
create new alleles
some mutations lead to survival improvements
gene flow (gene migration)
movement of alleles between populations
continual gene flow reduced divergence between two populations (creates bigger gene pool)
genetic drift
changes in allele frequencies due to chance or random event
likely to occur -
with severe inbreeding
after bottleneck effect
when founders start a new population
stronger effect in small populations
bottleneck effect
random event prevents the majority of individuals from contributing to the next generation
next generation is composed of a small subset of the gene pool
founder effect
new population started from just a few individuals
alleles carried by population founders directed by chance
formerly rare alleles will either occur at a higher frequency in the new population or be absent in the new population
non-random mating
individuals choose own mate
selection/ rejection based on phenotypes
increases/ decreases certain alleles
