Evolution Flashcards
Heterozygous Advantage
individuals who are heterozygous
at a certain locus have an advantage for survival.
gene flow
a population loses or gains alleles by genetic
additions/subtractions.
gene drift
unpredictable fluctuation in allele frequencies from one generation to the next.
gene pool
all of the available alleles at all loci in all the
members of the population
convergent evolution
distantly related species can resemble one another
homologous structures
common structures in different organisms
analogous structures
which evolved independently to have the same or similar function, and thus may appear on the surface to have a similar structure, but often this is very different from one organism to another.
vestigial structure
A structure found in an organism that is no longer in use but may have been useful at some point in the organism’s life.
Natural selection can alter the frequency of heritable traits in three ways
directional, disruptive, and stabilizing selection
how fossils form
An organism dies and quickly becomes buried in sediment
As many more layers of sediment form, it squeezes the layers below, eventually turning them into sedimentary rock.
While this is happening, water seeps into the bones and teeth, eventually turning them into stone as it leaves behind minerals.
Evidence for Evolution
fossil records vestigial organs homologous structures embryology molecular homologies convergent evolution biogeography direct observation
Factors that affect Natural Selection
Overpopulation: mature rapidly, live short lives, have many offspring, doesn’t take care of their young, population not regulated.
Producers: mature slowly, live long lives, few offspring at a time, care for their young, population stabilizes
