Truly, Madly, Deeply
There's a lot of talk of savagery in Cloud Atlas. Before we can analyze it, though, we have to define savagery. Meronym is nice enough to do that for us about halfway into the book: "The savage sat'fies his needs now. He's hungry, he'll eat. He's angry, he'll knuckly. [...] His master is his will, an' if his will say-soes 'Kill' he'll kill. Like fangy animals" (6.1.327). In plain English: human instinct is destructive. It wants to feed, fight, fornicate, and kill. Like a shark. And a person who gives in to this nature without any thought, without thinking of how it affects others, is a savage.
With that definition, it's hard to find a character in the book who isn't a savage. Pretty much everyone but Adam Ewing is one in his section. Both Frobisher and Ayrs could be called savages in one way or another. Frobisher, having an affair with Ayrs's wife, even accuses her of savagery, saying, "There's joylessness in [Jocasta's] lovemaking. No, a savagery" (2.9.3).
Seaboard Corp.: savages. Timothy Cavendish: a savage. The consumers of Unanimity: all savages. So what does it all mean? Morty Dhondt says it best when, taking his cure from Nietzsche, he says, "Our will to power, our science, and those v. faculties that elevated us from apes, to savages, to modern man, are the same faculties that'll snuff out Homo sapiens before this century [the 20th] is out" (10.1.19). If we give in to our nature and become savages, we will eventually destroy the world. Do you think we're already destroying it? If so, can we ever turn back?