A new Tree of Life; another comprehensive article (Evolution)

by David Turell , Saturday, April 16, 2016, 19:14 (3141 days ago) @ David Turell

David: Comment: Looking at purpose, one must understand how soil comes from lava. It is broken down by erosion, rain, lichens and bacteria, as simplistic geologic view. We eukaryotes live because of soil. A rocky Earth had to be prepared to be fertile Earth to give us plants as a major source of energy. This 3+ billion years of preparation for the multicellular seems like a good plan for me. God, after all, has all the time He wants.-This paper shows further how bacteria prepared Earth for life by breaking down iron:-https://www.sciencedaily.com/releases/2016/04/160415125954.htm
 
"A pair of papers from a UW-Madison geoscience lab shed light on a curious group of bacteria that use iron in much the same way that animals use oxygen: to soak up electrons during biochemical reactions. When organisms -- whether bacteria or animal -- oxidize carbohydrates, electrons must go somewhere.-"Iron is the fourth-most abundant element on the planet, and because free oxygen is scarce underwater and underground, bacteria have "thought up," or evolved, a different solution: moving electrons to iron while metabolizing organic matter.-"These bacteria "eat organic matter like we do," says Roden. "We pass electrons from organic matter to oxygen. Some of these bacteria use iron oxide as their electron acceptor. On the flip side, some other microbes receive electrons donated by other iron compounds. In both cases, the electron transfer is essential to their energy cycles."-"Iron-metabolizing bacteria have been known for a century, Roden says, and were actually discovered in Madison-area groundwater. "Geologists saw organisms that formed these unique structures that were visible under the light microscope. They formed stalks or sheaths, and it turned out they were used to move iron."-"Roden and He are geobiologists, interested in how microbes affect geology, but the significance of microbes in Earth's evolution is only now being fully appreciated, Roden says. "Eyebrows rose when we contacted the Biotech Center three or four year ago to discuss sequencing: 'Who are these people from geology, and what are they talking about?' But we stuck with it, and it's turned into a pretty cool collaboration that has allowed us to apply their excellent tools that are more typically applied to biomedical and related microbial issues."-"These are fundamental studies, but these chemical transformations are at the heart of all kinds of environmental systems, related to soil, sediment, groundwater and waste water," says Roden. "For example, the Department of Energy is interested in finding a way to derive energy from organic matter through the activity of iron-metabolizing bacteria." These bacteria are also critical to the life-giving process of weathering rocks into soil. (my bold)-"Some of the iron-metabolizing bacteria appear quite early on the tree of life, making the studies relevant to discovering the origins of life, but the findings also have implications in the search for life in space, Roden says. "Our support comes from NASA's astrobiology institute at UW-Madison. It's possible that on a rocky planet like Mars, life could rely on iron metabolism instead of oxygen."-Comment: Note the bold. Bacteria made the Earth inhabitable