What is variation?
Humans differ in many ways - from hair colour, to eye colour, size and weight - we're all different. The physical, psychological and mental differences that occur between members of a species is known as variation. It can be the result of environmental factors as well as genetic factors such as meiosis, random fertilization and mutation. Environmental variation occurs when an individual's characteristics may change over time as they are exposed to certain factors. For example, a person may naturally be fair-skinned, but after continued sun exposure, their skin becomes tanned. Genetic variation is vital, as it allows for evolutionary changes, to ensure that an organism has the best chances of survival and it is also important to the process of natural selection - the determination of the most desired traits by one's environment.
As variation is the result of genetics, mating patterns have a large influence. When a population breeds, nonrandom mating can occur. This is when an individual specifically chooses who they want to mate with, based on the characteristics that an individual possesses. There are two types of nonrandom breeding, which have different effects. One form is known as inbreeding, and it occurs when individuals with similar genotypes, and thus characteristics have a higher chance of mating with each other than those of different genotypes. This however leads to a reduction in variation, as the same traits and characteristics are being passed on. The other form of nonrandom mating is known as outbreeding. This is when individuals who possess a certain genotype will mate with an individual of a different genotype, and who therefore, possesses different traits. This leads to an increase in variation, as different traits are entering into genotypes of offspring, resulting in a wider overall range of characteristics.
As variation is the result of genetics, mating patterns have a large influence. When a population breeds, nonrandom mating can occur. This is when an individual specifically chooses who they want to mate with, based on the characteristics that an individual possesses. There are two types of nonrandom breeding, which have different effects. One form is known as inbreeding, and it occurs when individuals with similar genotypes, and thus characteristics have a higher chance of mating with each other than those of different genotypes. This however leads to a reduction in variation, as the same traits and characteristics are being passed on. The other form of nonrandom mating is known as outbreeding. This is when individuals who possess a certain genotype will mate with an individual of a different genotype, and who therefore, possesses different traits. This leads to an increase in variation, as different traits are entering into genotypes of offspring, resulting in a wider overall range of characteristics.