Tree of LifeThe first record we have of a classification system for living organisms comes in the wr

Tree of LifeThe first record we have of a classification system for living organisms comes in the writings of Aristotle, who divided organisms into just Plants and Animals. By the time I first began to study biology (not quite as far back as Aristotle, but close), there were five kingdoms of living organisms: Animalia, Plantae, Fungi, Protista, and Monera, based on the system of classification developed by Linnaeus in the mid-1700’s. Animalia, Plantae, and Fungi were pretty obvious areas of classification to me, even as a freshman biology student. Monera was where bacteria were placed and Protista, of course, was the junk drawer of the kingdoms, where all of the odds and ends were put.It was not until I was doing summer work writing curricula at NASA -JSC in the late 1990’s-early 2000’s that I discovered the three-domain system of classification, which was first published by Carl Woese (of University of Illinois) and his colleagues in the 1970’s. In the wake of the controversial announcement of possible proof of life on Mars inside the meteorite ALH84001, I learned a lot about extremophilic microbes and the domain system made perfect sense to me. Woese’s system is now widely accepted by many scientists and is made up of three main branches, called domains.Today, a team of researchers led by Jillian F. Banfield of the University of California, Berkeley, published a new version of the tree of life, based on the genomes of more than 3000 species of organisms from all facets of life, including 1011 previously unknown species of microbes the team collected in recent years. Using a supercomputer to look at possibilities, they found one tree that best represented the data. As you might have expected, all of the Eukaryotes, including humanity, are a very small part of the tree. Next to the Eukaryotes is Domain Archaea, with the vast majority of the tree being made up of bacteria. What might surprise some is that a great many of these newly discovered microbes were found not in extreme environments, but in the soil under our very feet and according to this proposed tree, half of Domain Bacteria (the large purple section to the right, labeled “Candidate Phyla Radiation) are only a prediction thus far and have yet to be discovered.CWImagehttp://nyti.ms/1WowgL5Sourceshttp://nyti.ms/1WowgL5http://bit.ly/1N5gjHuhttp://bit.ly/1UX972V -- source link

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