Eubacteria

From Palaeos.org

Scanning electron micrograph of Escherichia coli (Proteobacteria : Gamma Proteobacteria : Enterobacteriales : Enterobacteriaceae)

Life
`--LUCA
   |--Eubacteria
   |  |    (concerning clades, see note, below)
   |  |--Actinobacteria
   |  |--Aquificae
   |  |--Clostridea 
   |  |--Cyanobacteria 
   |  |--Didermata
   |  |--Firmicutes 
   |  |--Proteobacteria 
   |  `--Thermotogae 
   `--Neomura
      |--Archaea
      `--Eukarya

This is the Domain of the Germs. The Eubacteria, in their hundreds of trillions, are the reasons you weren't allowed to pick up the candy you dropped on the floor or eat that egg salad that looked so good a week ago. They are behind every torture you have ever suffered at the hands of the dentist, and they are the root cause of childhood afflictions from antiseptics to acne. They have a lot to answer for. Then again, they're probably not too happy with us, either. Its hard to tell, since bacteria don't go in much for light conversation or email rants. They grow, or they don't, just as they have for the last three or four billion years, and without making much fuss about it. Bacterial psychology is thus a rather limited field. But such simplicity has its advantages. We are never tempted to paint human thoughts and emotions onto a 4 µ long pill-shaped blob of protoplasm. We can safely view the bacterium for what it is, a small biochemical machine, without having to steer the usual narrow passage between the twin perils of anthropomorphism and reductionism.

However, to say that the Eubacteria are biochemical machines is not to belittle them. Consider Gomphosphaeria Kützing 1836, the somewhat larger than average, but otherwise undistinguished, phytoplanktonic Cyanobacterium [1] on the right. If we allowed a single cell of Gomphosphaeria to grow and divide under optimum conditions for only about 4.5 days we would be up to our armpits in Gomphosphaeria over the entire surface of the Earth [2]. Even man's most perfect machines, for example the 1976 Toyota Corolla, couldn't come close to matching this kind of performance.

Currently included pages:

• Eubacteria - Cell Structure - This page will be devoted to considering the basic structural and functional units of the Eubacteria as biological machines. More specific matters, as well as considerations of ecology, phylogeny and evolution will be taken up in connection with more the specific groups to which these matters pertain.
• Eubacteria - Phylogeny - cladogram and suggested phylogentic relationships of the Eubacteria

Footnotes

[1] Phytoplankton is an ecological term referring to any photosynthetic microorganism normally found in water, including forms (like Gomphosphaeria) that are often found attached to some substrate. The Cyanobacteria are the large group of very basal photosynthetic Eubacteria traditionally called "blue-green algae" because they use phycocyanin (a bluish pigment), as well as chlorophyll a (a green pigment), for photosynthesis of carbohydrates.

[2] Try it. Assume each cell is a cylinder 4 µ long, with a radius of 1 µ (1 µ = 10-6 m). Further assume a generation time of 1 hour and that the radius of the earth is 6.35 X 106 m. You can assume what you like about armpit height. It doesn't make much difference to the result.

Palaeos com - Eubacteria

Credits: Palaeos com page ATW030228, this page reorganised MAK060923

Catgeory:Eubacteria