Which of the following are examples of postzygotic barriers in speciation?

• A. Mechanical isolation and gametic isolation
• B. Geographic isolation and ecological isolation
• C. Hybrid sterility and hybrid breakdown
• D. Temporal isolation and behavioral isolation

Answer: (C)

Verified step by step guidance

1. Understand the concept of postzygotic barriers: These are reproductive barriers that occur after fertilization, affecting the viability or fertility of the hybrid offspring.
2. Identify examples of postzygotic barriers: Hybrid sterility refers to hybrids that are unable to reproduce, while hybrid breakdown involves hybrids that may be fertile but produce offspring with reduced fitness.
3. Differentiate postzygotic barriers from prezygotic barriers: Prezygotic barriers prevent fertilization, such as mechanical isolation (physical differences) and gametic isolation (incompatibility of gametes).
4. Recognize that geographic and ecological isolation are prezygotic barriers: These prevent mating due to physical separation or different habitats.
5. Note that temporal and behavioral isolation are also prezygotic barriers: Temporal isolation involves differences in mating times, while behavioral isolation involves differences in mating rituals.