Which factor might contribute to the development of a new species?

The development of a new species often hinges on significant reproductive isolation. This factor plays a crucial role in speciation as it prevents different populations from interbreeding, allowing them to evolve independently. When populations are reproductively isolated, whether through geographic barriers, behavioral differences, or temporal factors, genetic differences can accumulate over generations. These differences may lead to the emergence of distinct traits that characterize each group, ultimately resulting in the formation of new species.

For example, if a population of organisms becomes divided by a mountain range, the groups on either side may adapt to their specific environments, leading to divergent evolution. If these adaptations become pronounced enough and the groups cannot interbreed, speciation is likely to occur.

In contrast, constant environmental conditions might not provide enough selective pressure for significant changes to occur. Random mixing of gene pools could facilitate gene flow, inhibiting the divergence required for speciation. Immediate environmental changes could lead to extinction events or rapid adaptations but may not necessarily establish the reproductive isolation needed for the long-term development of new species.