The presence of cilia in wide segments of the eukaryote world (though rare in plants) shows the connectedness of life. A tiny paramecium has cilia, as do arthropods, as do mammals, as do humans. The cilia that sweeps food down the oral groove of a paramecium is structurally like the cilia that sweeps mucus in the human respiratory tract.
Both cilia and flagella (but especially flagella) have been a focus of the debate between Darwinists and those advocating intelligent design. For those advocating Darwinism, cilia naturally originated by descent from modification and natural selection. For those advocating intelligent design, the structure of cilia/flagella is an example of an irreducibly complex part that could not come about due to natural selection over gradual stages of descent with modification; rather, it must have come from an intelligent designer (God). (See Talk:Flagellum for a detailed discussion.). Unification Thought bridges these two perspectives, affirming both the creative power of God and the development of new designs in stages as seen in descent with modification. Any dichotomy between a creator God and descent with modification is an artificial and unnecessary one, as the presence of a creator God does not preclude development of life in stages, with new designs coming on the foundation of previous stages—albeit a development where the main creative force is not random forces, as seen in natural selection, but one involving design..