They help an environment because they create an ecosystem allowing animals to thrive and live a lifecycle with the resources they need.
Alleles are the alternative form of a gene that code for a given trait, the alleles may be dominant or recessive or exhibit incomplete dominance. When two alleles are similar they are referred to as homozygous while they are not similar they are referred to as heterozygous. Based on the founder effect, rare alleles and combinations may be improved in new populations because of the reduced size of the initial population.
