There are days when I wish that the Woesian Three Domain scheme were wrong. Not that I would be happier if there were four or five or whatever number of domains. What would please me would be an escape from what I feel is an unnecessarily oppressive way of thinking, the seating of phylogeny (and its acolyte, genomics) alone at the head of the table. Why do I say this? Because as essential as phylogeny is to our understanding of the evolution of living organisms, equally vital is ecology to comprehend present day life. While it’s good to know where you come from, it’s equally important to know where you are and what you’re doing there. The Spanish philosopher Ortega y Gasset said it well: Yo soy yo y mi circunstancia (I am I and my circumstance).
A sole focus on phylogeny forces the past ahead of the present. Compare the two figures; they represent two different worldviews. One highlights the deep clefts between the three domains, the other is integrative and does away with such barriers. Maybe it is not phylogeny’s job to emphasize ecology, but neither should we be fixated on evolution alone. Obviously no one is, so I apologize for erecting a straw man. Yet let me voice a wish: I would like to see a wider ranging acknowledgement of each organism’s give-and-take with its environment. Famed evolutionary biologist and geneticist Dobzhansky once said: Nothing in Biology makes sense except in the light of evolution. Do I dare modify this well-known dictum to read: Nothing in Biology makes sense except in the light of evolution and ecology.
As an evolutionary plant ecologist, I am excited beyond belief at the prospect that assimlation of phylogeny into what we understand and teach will lead to microbiologists following the lead of botanists and rewrite their textbooks so that we can stop using the misleading (paraphyletic) group called "prokaryotes". It's not one or the other. Each illuminates and makes the other field of study more rich.
Posted by: Tom Donahue | January 15, 2013 at 12:00 PM