Evolution of Population Flashcards
adaptation
heritable trait or behavior in an organism that aids in its survival and reproduction in its present environment
adaptive evolution
increase in frequency of beneficial alleles and decrease in deleterious alleles due to selection
allele frequency
rate at which a specific allele appears within a population (aka gene frequency)
artificial selection
the process by which humans choose individual organisms with certain phenotypic trait values for breeding
assortative mating
when individuals tend to mate with those who are phenotypically similar to themselves
beneficial mutation
a type of mutation that has a positive effect on an organism
bottleneck effect
magnification of genetic drift as a result of natural events or catastrophes
convergent evolution
process by which groups of organisms independently evolve to similar forms
deleterious mutation
genetic alteration that increases an individual’s susceptibility or predisposition to a certain disease or disorder
directional selection
selection that favors phenotypes at one end of the spectrum of existing variation
diversifying (disruptive) selection
selection that favors two or more distinct phenotypes
divergent evolution
process by which groups of organisms evolve in diverse directions from a common point
evolutionary (Darwinian) fitness
individual’s ability to survive and reproduce
fixation (fixed)
the preservation of biological tissues from decay due to autolysis or putrefaction
founder effect
event that initiates an allele frequency change in part of the population, which is not typical of the original population
gene flow
flow of alleles in and out of a population due to the individual or gamete migration
gene pool
all the alleles that the individuals in the population carry
genetic drift
effect of change on a population’s gene pool
genetic variabillity
diversity of alleles and genotypes in a population
Hardy-Weinberg Equilibrium
allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences
Heterozygote advantage
the case in which the heterozygous genotype has a higher relative fitness than either the homozygous dominant or homozygous recessive genotype
inbreeding
mating of closely related individuals
inbreeding depression
increase in abnormalities and disease in inbreeding populations
migration
a pattern of behavior in which animals travel from one habitat to another in search of food, better conditions, or reproductive needs
modern synthesis
overarching evolutionary paradigm that took shape by the 1940s and scientists generally accept today
negative selection
the selective removal of alleles that are deleterious
neutral mutation
mutation that neither benefits nor harms the individual
nonrandom mating
changes in a population’s gene pool due to mate choice or other forces that cause individuals to mate with certain phenotypes more than others
population genetics
study of how selective forces change the allele frequencies in a population over time
positive selection
the process by which new advantageous genetic variants sweep a population
relative fitness
individual’s ability to survive and reproduce relative to the rest of the population
selection pressure
environmental factor that causes one phenotype to be better than another
sexual dimorphism
phenotypic difference between a population’s males and females
stabilizing selection
selection that favors average phenotypes
variation
genetic differences among individuals in a population
