Biol110- test2.txt

group of individuals of same species, living in same geographic area

all of the alleles present in a population at a particular time

Natural selection acts on _________, but populations evolve

no mutation, mating at random, infinte population, no immigrating, no natural selection: qualities of equilibrium in __________ principle

Smaller populations are more sensitive to change

______ effect- catastrophe that decimates large population

_____ effect- migration of small group away from large population

sickle cell is an example of _____________: the change in DNA of an organism (heritable)

flow-members of population come and go - can change allele frequency

mates may NOT be chosen at random (self fertilization, assortative mating) � changes genotype frequencies but not allele frequencies

adaptation

_______ selection: mean phenotype is favored (ex. large/small child birth size)

_______ selection: an extreme towards one end of the spectrum of variation (ex. pesticide and antibiotic resistance)

_______ selection: both extremes are selected, while the non-distinct median range is overlooked and phased out (ex. long horned dung beetles vs. tunneling dung beetle)

_______ selection: "heterozygous advantage"- it has increased fitness over its homozygous counterparts (ex. sickle cell carrier)

_______ selection: the more common phenotype is selected against

_______ selection: competition within a sex for mating privilege (ex. male crabs fighting)

_______ selection: mating selection based on preferences (ex. male peacock)

a group of individuals who interbreed, or have the potential to interbreed in nature.

speciation occurs when any condition blocks gene flow between two ___________

_______ isolation: species live in different areas or different habitats (brown bears vs. polar bears)

_______ isolation: isolated by season or day night cycle (plants flowering at different times)

_______ isolation: courtship displays, mating calls, pheromones

_______ isolation: male and female reproductive organs coevolve (lock and key strategy)

mating may occur, but fertilization does not (inhospitable female reproductive tract)

__________ isolation: zygotes form but do not survive OR cannot reproduce. Also, hybrid inviability (genes cannot function together) -ex. male donkey and female horse = mule with abnormal meiosis (cant reproduce)

_________ speciation: a physical barrier prevents gene flow between a species (ex. islands)

__________ speciation: new species within a species' home territory (ex. polyploidy haploid vs. diploid in plants causes this)