"Islands may seem remote and insignificant," David Attenborough says at the close of the first episode of Planet Earth II, which premieres in the U.S. on Saturday, "but they are home to some of the most precious wildlife on earth." By the end of episode one — which is dedicated to islands and the life they hold (sloths, crabs, penguins, and Komodo dragons, to name a few) — it's tempting to zoom out to an even bigger view than Planet Earth's sweeping vistas afford, and look at the Earth itself.