**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.
Genetic drift describes random fluctuations in the numbers of gene variants in a population. Genetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time.These variations in the presence of alleles are measured as changes in allele frequencies.enetic drift takes place when the occurrence of variant forms of a gene, called alleles, increases and decreases by chance over time. These variations in the presence of alleles are measured as changes in allele frequencies.