AP Bio Evolution Flashcards

the change in a population's inherited traits from generation to generation
natural selection
the evolutionary process by which favorable traits that are heritable become more common in successive generations
evolutionary adaptations
inherited traits further developed through evolution
the slow, gradual steps of change
the philosophy of science that believes that the natural processes operating now are doing so at the same rate as in the past
artificial selection
the intentional breeding of certain characteristics over others
any similarity between structures due to shared ancestry
homologous structures
any structures that are sismilar due to shared ancestry
vestigial organs
anatomical structures of organisms in a species which have lost much or all of their original function due to evolution
the study of evolutionary relatedness among various groups of organisms
the collection of people or organisms of a particular species living in a given geographic area or space
one of the basic units of biological classification
Hardy-Weinberg Theorum
a relationship between the frequencies of alleles and the genotype of a population
Hardy-Weinberg equilibrium
when alleles are in perfect Hardy-Weinberg proportion
Hardy-Weinberg equation
evolution that occurs at or above the species level
bottleneck effect
an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing
founder effect
establishing a population by a small number of individuals, carrying only a small fraction of the original population's genetic variation
gene flow
the transfer of gene alleles from one population to another
balanced polymorphism
natural selection maintaining polymorphisms in a population
heterozygote advantage
when heterozygotes have greater fitness than homozygotes
hybrid vigour
the increased strength of various characteristics in hybrids
stabilizing selection
a type of natural selection in which genetic diversity decreases as the population stabilises on a particular trait value
directional selection
when natural selection favors a single allele and therefore, allele frequency continuously shifts in one direction
diversifying (disruptive) selection
a type of evolution that simultaneously favors at both extremes of the distribution
sexual dimorphism
the systematic difference inbetween individuals of different sexes in the same species
the occurrence of small-scale changes in allele frequencies in a population over a few generations
the evolutionary process by which new biological species arise
phyletic evolution
genetic changes that occur within an evolutionary line
branching evolution
when a species evolves separately from itself to form separate groups
prezygotic barriers
barriers that prevent mating between species/prevention of egg fertilisation
morphical species concept
when species are classified as the same species based on anatomy
recognition species concept
a concept that defines a species as a set of organisms that recognise each other as potential mates
cohesion species concept
defines a species as a group of organisms that can exchange genetically
ecological species concept
defines a species as a set of organisms that are adapted to a particular set of resources
evolutionary species concept
a species is a lineage evolving separately from others and with its own unitary evolutionary role and tendencies
allopatric speciation
when populations physically separated by an extrinsic barrier evolve so that if the barrier breaks down, they can't breed
adaptive radiation
rapid speciation of a single or a few species to fill many ecological niches
sympatric speciation
different species sharing the same territory
punctuated equilibrium
rare events that cause milestone evoltion branches
convergent evolution
where unclosely related organisms evolve similar traits as a result of having to adapt to similar environments