Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities?
A) Cilia and flagella arise from the centrioles.
B) Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.
C) Motor proteins such as dynein must have evolved before any of these four kinds of structure.
D) Cilia and flagella coevolved in the same ancestral eukaryotic organism.
E) Natural selection for cell motility repeatedly selected for microtubular arrays in circular patterns in the evolution of each of these structures.
