AP BIO unit 7

Similar structure, different function

Different structure, similar function

a localized group of individuals capable of interbreeding and producing fertile offspring

differences between gene pools of separate populations or population subgroups

consists of all the alleles for all loci in a population

acts on individuals, but only populations evolve

a change in allele frequencies in a population over generations

More generations per unit time allows for mutations to quickly generate genetic variation

Shuffles existing alleles into new combinations

describes population that is not evolving

No mutations, Random mating, No natural selection, Large population, No Gene flow

frequency of the dominant allele

frequency of the recessive allele in the population

percentage of homozygous dominant individuals

percentage of homozygous recessive individuals

percentage of heterozygous individuals

describes how allele frequencies change over generations due to chance

occurs when a few individuals become isolated from a larger population

a sudden reduction in  population size due to a change in the environment

consists of the movement of alleles among populations

favors individuals at one end of the phenotypic range

favors individuals at both extremes of the phenotypic range

favors intermediate variants and acts against extreme phenotypes

natural selection for mating success

competition among individuals of one sex (often males) for mates of the opposite sex

occurs when individuals of one sex (usually females) are choosy in selecting their mates

development of a new species

speciation takes place in populations with geographically separate ranges

the speciation of organisms when the environment changes and new resources are available (opens new ecological niches)

speciation takes place in geographically overlapping populations

gradual changes over time and transitional species

long periods of stasis (equilibrium) punctuated by episodes of speciation

the accumulation of changes associated with the transformation of one species into another

the budding of new species from a parent species that still exists

impede mating between species or hinder the fertilization of the ova

two species live in different habitats; low occurrence of interaction

special signals that attract mates, along with elaborate behaviors unique to a species

two species breed at different times (day, seasons, years)

anatomically incompatible

gametes rarely fuse to form a zygote; sperm might not be able to travel to the ova

prevent the hybrid zygote from developing into a viable, fertile adult

hybrids are less viable (usually don’t survive)

hybrids are completely or largely sterile

the first generation of hybrids are fertile, but as those mate with one another, the offspring of the next generation are sterile

defines a species in terms of its ecological niche, the set of environmental resources it uses

characterize species in terms of structural features

defines a species as a set of individuals that share a common ancestor