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

by David Turell , Saturday, April 16, 2016, 15:40 (3142 days ago) @ David Turell

This article has a great diagram of the new 'tree' which is not a tree at all:-http://www.theatlantic.com/science/archive/2016/04/the-tree-of-life-just-got-a-lot-weirder/477729/-"We visible organisms should be the small wedge. We're latecomers to Earth's story, and represent the smallest sliver of life's diversity. Bacteria are the true lords of the world. They've been on the planet for billions of years and have irrevocably changed it, while diversifying into endless forms most wonderful and most beautiful. Many of these forms have never been seen, but we know they exist because of their genes. Using techniques that can extract DNA from environmental samples—scoops of mud or swabs of saliva—scientists have been able to piece together the full genomes of organisms whose existence is otherwise a mystery.-"Using 1,011 of these genomes, Laura Hug, now at the University of Waterloo, and Jillian Banfield at the University of California, Berkeley have sketched out a radically different tree of life. All the creatures we're familiar with—the animals, plants, and fungi—are crowded on one thin branch. The rest are largely filled with bacteria.-***-“'This is humbling,” says Jonathan Eisen from the University of California, Davis, “because holy **#$@#!, we know virtually nothing right now about the biology of most of the tree of life.”-***-"From every organism in these samples, the team analyzed sixteen proteins that form part of the ribosome—a universal machine that's found in all living things and that makes other proteins. Every organism has its own version of these proteins, and as new species diverge from each other, their versions become increasingly different. So by comparing these sixteen proteins, Hug and Banfield could work out how closely related their various microbes were, and draw their tree of life.-***-"It has two main trunks—one full of bacteria and another comprised of archaea, a dynasty of single-celled microbes that look superficially similar but run on very different biochemistry. The eukaryotes—the domain that includes all animals and plants—are but a thin branch coming off the archaeal trunk. (This hints at a much broader debate about the origin of eukaryotes.-***-"There's also a grander answer: we are the first and only organisms in Earth's history with the capacity to find and understand the others. We've done a reasonable job with the tools we have, but it's clear that our understanding of life is so unfinished that it makes iceberg tips look complete. If we care about knowing our world, and our place in it, then our work is just starting."-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.