The environment in which the organism is in, through the agents of natural selection. Passes the genes on to the next generation, on which natural selection continues to operate. What are the four ideas making up the modern synthesis of evolution. Natural selection, mutation, random genetic drift and isolation Mutations. Approximately, every gamete, egg or sperm, contains one mutation.
Mutation can be beneficial, neutral or harmful depending on the environmental conditions Kingdoms.
Random genetic drift Isolation leads to the rise of genetic differences as a consequence of the mutations, agents of natural selection and RGD on genetic frequencies in different environments. No, in some subspecies their genes have not become different enough to prevent mating, as in humans. There is exchange of genes between the adjacent groups especially at their boundaries so neither subgroup is genetically unique. There is no or little exchange of genes between organisms in distant groups following prolonged isolation. Separate mutations, adaptations to the their environments, different random genetic drift occurring in each subspecies.