The term is also frequently used to refer to the appearance of a new species. The next and subsequent generations are referred to as f2, f3, etc. More precisely, it is the collective genotype of a population. A gene may be made up of hundreds of thousands of DNA bases. Genes are responsible for hereditary characteristics in plants and animals.
Genetic drift occurs most rapidly in small populations.
In large populations, random deviations in allele frequencies in one direction are more likely to be cancelled out by random changes in the opposite direction. Genetic mechanisms are the underlying foundation for evolutionary change. Genetics is the branch of science that deals with the inheritance of biological characteristics. See Human Genome Project . Genotype can refer to an organism's entire genetic makeup or the alleles at a particular locus.