Vital Question: Energy, Evolution, and the Origins of Complex Life

by Nick Lane

But now imagine that lateral gene transfer predominates. So we sequence the ribosomal RNA, and it tells us we are dealing with a bird. Only now do we look at this ‘bird’. It turns out to possess a trunk, six legs, eyes on its knees, fur; it produces eggs like frogspawn, lacks wings and howls like a hyena. Yes, of course that is absurd; but this is precisely the problem that we face with bacteria. Monstrous chimeras regularly stare us in the face; but because bacteria are typically small and morphologically simple, we don’t scream. Nonetheless, in their genes bacteria are almost always chimeric, and some are real monsters, genetically as mangled as my ‘bird’. Phylogeneticists really ought to scream. We can’t infer what a cell might have looked like, or how it might have lived in the past, on the basis of its ribosomal genotype.