"All communication—and, eventually, all language—has evolved slowly through natural selection. The honey dance of the bees; the twittering song of the starling; the ballet dance of the male manikin bird—all achieved their impressive complexity slowly. Natural selection has no foresight and no goal in mind, so the solutions that will be favored are those that best suit the problem at hand. Making many different kinds of sounds is useful—not because they lay the basis for a language but because messages can be clear and unequivocal. Animals have large repertoires as a side effect of their communication needs, not because they actually need large repertoires.

Grammar may not be necessary in alien languages.

Perhaps grammar really distinguishes language from non-language. But many animals also have a grammar of sorts. For example, monkeys, with a fairly limited repertoire of sounds, combine those sounds in different ways to create new meanings. But as with the large repertoires of birds, this is just an evolutionarily efficient way of arranging sounds. Grammar seems to evolve as a byproduct and may not be necessary in animal or alien languages."