Chapter 10 - Evolutionary Genetics Flashcards
central concept in biology
evolution
one of the foundations of evolution
genetics
group of individuals of the same species
population
- series of partial or complete and irreversible transformations of the genetic structure of a population based principally on altered interaction with the environment
- 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
- heritable variation
- limited environmental opportunities
- changing environments
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
- mutation
- migration
- natural selection
- genetic drift
- gene recombination
increases variability within a population
mutation
adds genetic variability to a population
migration
- decreases genetic variability through elimation 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
results in the chance elimination of genotypes due to small population size
genetic drift
causes reshuffling of genes to produce new gene combinations for acceptance or rejection by selective forces of evolution
gene recombination
identification by humans of desirable traits in plants and animals, and the steps taken to enhance and perpetuate those traits in future generations
Artificial selection
genetic base in artificial selection
narrow
genetic base in natural selection
broad
- change in population’s gene pool over a succession of generations
- occurs over relatively brief period of time
microevolution