Final answer:
Speciation, as per the biological species concept, requires the evolution of two populations from one original, leading to reproductive isolation due to genetic divergence. Allopatric and sympatric speciation are two pathways for this process, enabled by prezygotic and postzygotic barriers.
Step-by-step explanation:
According to the biological species concept, for speciation to occur, two new populations must be formed from one original population and they must evolve in such a way that it becomes impossible for individuals from the two new populations to interbreed. Speciation involves either allopatric speciation (geographic separation) or sympatric speciation (occurs without geographical barriers within a population). Reproductive isolation plays a crucial role, where either prezygotic or postzygotic barriers prevent interbreeding, allowing populations to evolve independently.
Key Points in Speciation
- Speciation requires genetic divergence that leads to reproductive isolation.
- Environmental conditions can prompt changes leading to speciation.
- New traits can arise through mutations, or gene flow may introduce them.
According to the biological species concept, for speciation to occur, at least one gene, affecting at least one phenotypic trait, must change. The biological species concept defines a species as a group of organisms that can interbreed and produce viable offspring. When a gene that affects a phenotypic trait changes, it can lead to the development of new traits in a population, eventually leading to the formation of a new species.