Evolution, Natural Selection, Population Genetics, & Speciation Flashcards
adaptive radiation
Previously occupied niche that is now available. (other organisms were living there and outcompeted other species… but were wiped out!)
Allopatric speciation
Two groups of species become separated from each other for so long that they evolve into their own new species… if you attempt to put them back together they could no longer reproduce viable fertile offspring
biogeography
The study of the past and present distribution of organisms
Bottleneck
- forced case of genetic drift An event that drastically changes the size of a population… typically the surviving population is no longer genetically a good representation of the original population
Founder effect (forced causes of genetic drift)
Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool is not reflective of that of the original population
endemic
Endemic species: a species whose distribution is limited to a specific geographic area
think polar bears forced to live in arctic
Heterozygote advantage
Greater reproductive success of heterozygous individuals compared to homozygotes… because they usually tend to preserve variation within the gene pool
neutral varation
When a population carries several different alleles, it is usually likely that all those alleles are equally good at performing their job, therefore the allele does not affect a population’s fitness
Ex: being left or right handed… it doesn’t affect you negatively if you have either
Paleontology
The branch of science concerned with fossil animals and plants
Polyploidy
Heritable condition of possessing more than two complete sets of homologous chromosomes (is a result of an accident of cell division)
Can only cross with itself
More common in plants than animals
