So also with the archaea. They can live almost anywhere. But they are boring to look at. The point is not merely aesthetic. For Siefert, an accurate tree, or phylogeny, is the key to reconstructing the early evolution of life on Earth.
Microbes decompose the waste products of other living things, creating nutrients.
They are also used to make beer, bread, and yogurt. Some say life on Earth may have begun when microbes migrated here from outer space . Others say life sprang up out of a primordial soup of terrestrial chemicals. Establishing relationships demands comparisons. And making comparisons requires a yardstick, something common to every living organism.