Chapter 10: Evolutionary Genetics Flashcards
Who said, ‘Nothing in biology makes sense except in the light of evolution’?
Theodosius Dobzhansky
- one of the foundations of evolution;
- recognized by Darwin as the key to understand evolution
Genetics
the unit of evolution
population
a group of individuals of the same species
population
A series of partial or complete and irreversible transformations of the genetic structure of a population based principally on altered interaction with the environment.
Organic evolution
Chance processes, interacting with a changing environment, generated complex structures and organs that now have purposes which were not planned or designed.
Organic evolution
Requirements for Evolution (3)
- heritable variation
- limited environmental opportunities
- changing environments
Forces that modify gene frequencies in populations (5)
- mutations
- migration
- natural selection
- genetic drift
- gene recombination
a genetic mechanism that is not perfect but produces offspring that are sometimes slightly different from their parent/s
heritable variation
Insufficient resources for all individuals to survive and reproduce, leading to competition for necessary resources.
limited environmental opportunities
as conditions change, different individuals are best able to survive and reproduce.
changing environments
Forces that modify gene frequencies in populations maintain a state of dynamic balance through __ and
__ of genes
- inflow
- outflow
A force within a population that increases variability
mutation
A force that adds genetic variability to a population
migration
- decreases genetic variability through elimination of unfavorable mutations
- results in the perpetuation of those life forms having favorable characteristics that enable them to adapt to a specific environment
natural selection
a force that results in the chance elimination of genotypes due to small population size
genetic drift
a force causes the reshuffling of genes to produce new gene combinations for acceptance or rejection by selective forces of evolution
gene recombination
Processes driving divergence:
produces new genes into a population (2)
- mutation
- migration
Processes driving divergence: alter the frequency of genes that already exist in the population (3)
- natural selection
- sexual selection
- genetic drift
ancestral canine –> thousands to millions of years of natural selection –> (5)
- African wild dog
- Coyote
- Fox
- Wolf
- Jackal
- a change in a population’s gene pool over a succession of generations
- Occurs over relatively brief period of time (not millions of years)
microevolution
- total collection of genes in a population at any give time
- Reservoir from which members of next generation derive their genes
gene pool