The great variety of plant life (algae, bryophytes, pteridophytes, gymnosperms and angiosperms) did not appear at one time. It developed gradually over hundreds of millions of years, from simple aquatic forms to complex land plants, through the accumulation of variations and natural selection. Single abrupt mutations or seed dispersal alone cannot produce such diversity, and plants did not appear suddenly on earth. So diversification in plant life appeared due to long periods of evolutionary changes.
ConceptGradual evolution of plant diversity
Evolution in past papers
143 questions from this chapter have appeared across 27 exam years.
