The correct response is "All of the above."
Genetic drift, natural selection, and reproductive isolation can all contribute to the process of speciation in different ways.
- Genetic drift can lead to changes in allele frequencies in small populations, potentially resulting in the divergence of species over time.
- Natural selection can drive speciation by favoring different traits in different environments, leading to adaptation and the emergence of new species.
- Reproductive isolation is critical for speciation, as it prevents different populations from interbreeding, allowing them to evolve independently.
Therefore, all of these processes can lead to speciation.