Final answer:
The typical mutation rate for a gene in a natural population is 10⁻⁶ per gene per generation. The correct option is (D).
Step-by-step explanation:
The question asks about the typical mutation rate for a gene in a natural population. The mutation rate is the frequency at which a specified genetic element or set of elements within the genome undergoes mutation. Based on the provided information, the most accurate representation of the typical mutation rate is 10⁻⁶ per gene per generation, which is option D. This represents a chance of one in a million mutations occurring in a particular gene from one generation to the next.
The existence of mutations is crucial for evolutionary change as it generates the genetic variation necessary for natural selection to act upon. However, most mutations are either neutral or harmful, and beneficial mutations are rare. The probability of observing a particular helpful mutation in response to an environmental challenge is very low. This does not mean that mutations don't play a role, as over longer periods, they are fundamental to evolutionary processes and species adaptation.
Mutation rates can be influenced by several factors such as errors in DNA replication, exposure to certain chemicals, physical and biological agents, and spontaneous lesions. While the probability of a mutation in an individual gene is low, the vast number of genes present in an organism means that the genome as a whole is likely to experience at least one mutation with each generation.