**If the bride's grandmother and grandfather were to walk together, the bride should ask someone to usher her single grandfather. This could be a female family member not in the wedding party (an aunt, a close cousin, etc.).
When new individuals enter a population: Genetic Drift: A change in allele frequencies of a gene pool due to chance or random events: Emigration: When individuals leave a population: Gene flow: The movement of alleles from one population to another: Mutations are one way : that new variation can be introduced into a gene pool. The bottleneck effect . is a genetic drift that occurs after an event greatly reduces the size of a population: The founder effect : is a type of genetic drift that occurs when a small number of individuals colonize a new area. Intersexual selection : this occurs when males display traits that are attractive to females: Intrasexual selection: this involves competition among males.
The random sampling style of genetic drift shrinks the gene pool and therefore alters the frequency the alleles are found in the population. Some alleles are completely lost within a generation due to genetic drift. This random change in the gene pool can affect the speed of evolution of a species. Instead of taking several generations to see a change in allele frequency, genetic drift can cause the same affect within a single generation or two.