Formation of one or more new species via reproductive isolation.

• A. Reproductive potential
• B. Species
• C. Speciation
• D. Cladistics

Answer: (C)

Speciation is the process by which one or more new species arise when populations become reproductively isolated from each other, stopping gene flow and allowing genetic differences to accumulate over time. When interbreeding between groups ceases, natural selection, genetic drift, and new mutations act independently in each population, leading to divergence in traits, behaviors, and genetics. Over enough time, these differences can become substantial enough that the groups can no longer produce viable or fertile offspring together, solidifying them as separate species. This makes speciation the best term for describing the formation of new species via reproductive isolation.

Reproductive potential, by contrast, refers to how many offspring an organism could produce, not to the origin of new species. A species is a recognized group of interbreeding organisms, not the process by which new species form. Cladistics is a method for inferring evolutionary relationships, not a mechanism that creates new species.