What impact does habitat fragmentation have on the process of speciation?

Habitat fragmentation significantly impacts the process of speciation by isolating populations and limiting gene flow. When an environment is fragmented, natural barriers such as roads, urban development, or agricultural practices divide previously continuous habitats, creating smaller, isolated patches. This isolation restricts individuals of the same species from interbreeding with one another, leading to reduced genetic exchange.

Over time, the separated populations may adapt to their specific environmental conditions, accumulating genetic differences due to natural selection, genetic drift, or mutation. This divergence can eventually result in reproductive isolation, where the populations become so genetically distinct that they can no longer interbreed even if they come into contact again. This process is a key mechanism of speciation, as it demonstrates how geographic and ecological factors can lead to the formation of new species.

The other options do not accurately reflect the ecological and genetic realities following habitat fragmentation. The introduction of gene flow or the merging of species populations contradicts the isolating nature of fragmentation, while the assertion that fragmentation has no effect overlooks the significant evolutionary consequences it can have.