Final answer:
The two main steps of speciation are geographic isolation, where a population is separated by physical barriers, and reproductive isolation, where the population develops mechanisms to prevent interbreeding, leading to genetic divergence and eventually speciation.
Step-by-step explanation:
The two main steps of speciation are:
- Geographic isolation - When a population is physically separated by geographical barriers such as mountains, rivers, or oceans, leading to reproductive isolation.
- Reproductive isolation - In addition to being geographically separated, the population must also undergo processes that prevent them from interbreeding with other populations once they come into contact again. This can be due to a variety of prezygotic and postzygotic barriers, such as differences in mating seasons, behaviors, or compatibility of gametes.
Over time, these isolated populations may undergo genetic divergence due to mutations, natural selection, and genetic drift, eventually leading to the formation of new species. Speciation can occur through allopatric speciation, where a geographical barrier leads to reproductive isolation, or sympatric speciation, where new species arise within a shared habitat without geographical barriers.
Predictions for other mechanisms of speciation in a population include ecological niches leading to speciation through adapting to different environmental conditions and morphological differences signaling the scientific definition of a subspecies when populations start to show distinctive physical traits.