Domestication of species results in what effect on biodiversity?

• A. Decreased biodiversity because only certain species are bred
• B. Increased biodiversity due to more species bred
• C. No change in biodiversity
• D. Widespread extinction of wild species

Answer: (A)

Domestication relies on selective breeding, where humans choose only certain traits and lineages to propagate. This concentrates genetic material into a few cultivated varieties and often replaces a wide range of wild types with a small number of domesticated forms. As a result, genetic diversity within those populations drops, and farming systems can become monocultures or dominated by only a few varieties. That reduction in variety, across crops and livestock, means overall biodiversity is decreased.

The other ideas don’t fit the common pattern: breeding many different new species would increase biodiversity, but domestication usually narrows genetic variety rather than broadening it; no change would ignore the clear effect of selective breeding; and widespread extinction of wild species is not an inherent outcome of domestication alone, though it can occur due to associated habitat changes.