[Campbell Biology P.582] Based on the timeline provided in the figure, which of the followin... | Practice Question

Based on the timeline provided in the figure, which of the following statements about the sequence or timing of evolutionary events are correct? Select all that apply

  • A: The Cambrian explosion occurred after the appearance of the oldest eukaryotic cells but before the origin of jawed vertebrates.
  • B: The colonization of land by tetrapods occurred after the origin of jawed vertebrates but before the appearance of flowering plants.
  • C: Multicellular eukaryotes appeared before single-celled eukaryotes.
  • D: Humans are depicted as appearing at the very beginning of the Phanerozoic Eon.

Explanation

Option A is correct: Oldest eukaryotic cells 1.8 bya -> Cambrian explosion 535-525 mya -> Jawed vertebrates 440 mya . Option B is correct: Jawed vertebrates 440 mya -> Tetrapods colonize land 375 mya -> Flowering plants 140 mya . Option C is incorrect as single-celled eukaryotes preceded multicellular ones. Option D is incorrect as humans appeared very recently, at the 'PRESENT' end of the timeline.