Topic 7 Evolution of Populations Flashcards
Microevolution
Change in allele frequency in populations over generations.
Gene
A portion of DNA that carries the genetic code for lots of things including traits.
Allele
Alleles are different forms of a gene that can encode for slight differences in traits, ex colour of eyes, inherited from parents.
Population
A localized group of a species that interbreed with one another and produce fertile offspring thus sharing a gene pool.
Gene Pool
The total range of alleles and genetic variance in a population.
Genotype
The actual genetic code that an individual carries.
Phenotype
The expression of an individuals genotype, given their environment and observable traits.
Mutations
Mutations are changes in an individuals DNA sequence, occurring often during the building of the DNA and errors during this time. Mutations must occur in gametes in order to be passed on and are random.
Relative Fitness
the relative ability of an individual to contribute alleles to the next generation.
Directional Selection
Natural Selection that favors individuals at one end of the phenotypic range think beak depth in ground finches on the island daphne major. Shift of the mean value of a trait maintaining the variance.
Genetic Drift
Random Changes in allele frequency across generations not due to natural selection. Can be due to random chance events. Higher population sizes are more resistant to genetic drift.
Fixed Allele
All members of a population contain a certain allele and all subsequent individuals in the population will have the same allele.
Bottleneck effect
Population is reduced in size in a same environment and the surviving population has a random new proportion of alleles commonly losing rare alleles in the process.
Founder Effect
A few individuals from a large population get dispersed to a new location and isolated from the original population.
Founder Effect
A few individuals from a large population get dispersed to a new location and isolated from the original population.
