[Campbell Biology P.550] According to the text 'Why Natural Selection Cannot Fashion Perfect... | Practice Question

According to the text 'Why Natural Selection Cannot Fashion Perfect Organisms,' which of the following are reasons why natural selection may not lead to ideally suited organisms? Select all that apply

  • A: Selection acts only on existing variations, and new advantageous alleles do not arise on demand.
  • B: Evolution is limited by historical constraints, meaning it modifies existing structures rather than creating new ones from scratch.
  • C: Adaptations are often compromises, where performing one function optimally may reduce the ability to perform another.
  • D: Organisms actively choose to evolve traits that are not perfect, to maintain biodiversity.
  • E: Natural selection is inherently random and therefore cannot consistently produce optimal adaptations.

Explanation

The text explicitly lists these three points under 'Why Natural Selection Cannot Fashion Perfect Organisms': '1. Selection can act only on existing variations,' '2. Evolution is limited by historical constraints,' and '3. Adaptations are often compromises.' Options D and E are not mentioned as reasons in the text.