Which term refers to the formation of new species?

• A. Speciation
• B. Biodiversity
• C. Acid rain
• D. Invasive species

Answer: (A)

Speciation is the formation of new species. It happens when populations diverge genetically over time and reproductive isolation arises, so they can no longer interbreed. This gene-flow stop can come from geographic separation (allopatric speciation) or from divergence within the same area (sympatric speciation), plus mechanisms that prevent mating or successful fertilization (prezygotic and postzygotic barriers). Over many generations, these changes accumulate, producing distinct lineages that become separate species.

To connect with context, think of how isolated populations can adapt to different environments or develop mating preferences that reduce interbreeding, eventually leading to two species where there was one.

Biodiversity, by contrast, refers to the variety of life in a region, not the process that creates new species. Acid rain describes environmental pollution that stresses organisms, not speciation. Invasive species are organisms introduced to new habitats and often disrupt native communities; they’re about movement and impact, not the origin of new species.