Population GENETICS

stabilizing selection directional selection disruptive selection Vocab list Population Genetics gene pool allele frequency genetic equilibrium genetic drift gene flow stabilizing selection directional selection disruptive selection speciation geographic isolation reproductive isolation gradualism punctuated equilibrium adaptive radiation divergent evolution convergent evolution coevolution

Changes in evolution occur in populations, not individuals Population Genetics Population Genetics Changes in evolution occur in populations, not individuals

entire collection of genes in a population allele frequency Population Genetics Population Genetics gene pool entire collection of genes in a population allele frequency number of times an allele appears in a gene pool genetic equilibrium gene pool which is not changing in allele frequencies a population at genetic equilibrium is not evolving

Change in small populations mutations Population Genetics Mechanisms for Change Change in small populations mutations introduces of new alleles into gene pool

random change in allele frequency over time Population Genetics Mechanisms for Change genetic drift random change in allele frequency over time

increase of possible alleles between populations Population Genetics Mechanisms for Change gene flow increase of possible alleles between populations this can change the allele frequency of both populations

Population Genetics Mechanisms for Change For larger populations natural selection is the significant factor which causes changes in allele frequency

Steps of Natural Selection Mechanisms for Change Steps of Natural Selection In nature organisms produce more offspring than can survive. Population Genetics

Steps of Natural Selection Population Genetics Mechanisms for Change Steps of Natural Selection 2. In any population, individuals have variations.

Steps of Natural Selection Population Genetics Mechanisms for Change Steps of Natural Selection 3. Individuals with certain useful variations survive in their environment, passing those variations to the next generation.

Steps of Natural Selection Population Genetics Mechanisms for Change Steps of Natural Selection 4. Over time, offspring with certain variations make up most of the population and may look entirely different from their ancestors.

stabilizing selection selection against extremes, favors the average Population Genetics Natural Selection on one variation stabilizing selection selection against extremes, favors the average

directional selection Population Genetics Natural Selection on one variation directional selection selection against one extreme, favors other extreme

selection against average, favors both extremes Population Genetics Natural Selection on one variation disruptive selection selection against average, favors both extremes

the production of two or more species what leads to a new species? Population Genetics Evolution of a Species speciation the production of two or more species what leads to a new species? geographic isolation physical barrier which separates populations

what leads to a new species? reproductive isolation Population Genetics Evolution of a Species what leads to a new species? reproductive isolation groups can no longer sexually reproduce ex: behavior, mating patterns, physical differences

species evolve at a slow constant rate Population Genetics Evolution of a Species Speed of speciation gradualism species evolve at a slow constant rate

punctuated equilibrium rapid significant changes over a short time Population Genetics Evolution of a Species Speed of speciation punctuated equilibrium rapid significant changes over a short time

new species develop from a single common ancestor Population Genetics Patterns in Evolution adaptive radiation new species develop from a single common ancestor

new species develop from a single common ancestor Population Genetics Patterns in Evolution divergent evolution new species develop from a single common ancestor

different species develop similar traits Population Genetics Patterns in Evolution convergent evolution different species develop similar traits

Patterns in Evolution co-evolution Population Genetics Patterns in Evolution co-evolution different species develop traits as a result of a close relationship with the other species