What are the major ways in which the genetic make-up of a population changes over time?

Answer 1

Generic makeup of a population refers to the the amount of genetic variation within that population and the variables that drive the genetic change. According to the Harvey-Weinberg equilibrium, genetic variation will remain at a constant each generation unless acted upon by the specific elements that cause the change.

These elements are:

1. Selection- the ability of a certain genotype to have better rates of survival in each generation (two types of selection: directional, overdominant)
2. Migration- the immigration of genes into and emigration our of populations will cause change
3. Genetic Drift- random changes in allele frequency
4. Mutation- this is a random change at the molecular level of the organism that will cause one of three effects in an individual’s genome. It will either be an advantage, disadvantage or neutral in the expression of the change.

These processes will have an effect on the genetic makeup of the population (measured in allele frequency). The allele frequency over a given time is what is known as the evolutionary change of a population (micro evolution).