Kathleen Rogers: Symbiotic Evolution
The Chemistry of Evolution
Bacteria, Geology and Blood
Ideas about the origins and evolution of life get constantly reversioned by the sciences. In 2005 I made a road trip with Oran Catts, Ionat Zurr and Paul Venouse to pay homage to the most ancient microbial ancestors of life on earth in a remote corner of Australia. Thrombolites and Stromatalites are living fossil communities of earliest bacteria occurring around the coast and within salt tidal lakes in Western Australia. The Thrombolites at Clifton Lake are rare archaeobacteria; these colonies of cells are the pre cursors of all living organisms on the earth. They sweat out layer upon layer of mineral limestone and these mats like some filthy swollen quilt appear in the shape of soft mounds. Billions of years old, these subtle generators of matter and photosynthesis opened a door to oxygenate the earth and in doing so left a geological trail of iron banding within the earth. This iron is a pre cursor of haemoglobin in our own red blood cells. Photographs and written descriptions give little indication of their scale or poetic impact. They have a strangely soothing presence and are curiously mesmerising. Watching their benign forms nesting at the edge of a lake you almost expect their creature like forms to move and speak. Evolutionary biology has inspired scientists and designers to explore the creative potential of “smart materials,” man-made materials modeled after nature that can adapt to changes in their environment and physically transform.These mutualistic bacterial communities are the key example of how symbiosis works.
The origin of cells with nuclei is exactly equal to the evolutionary integration of symbiotic bacterial communities. These microbial symbionts are part of the evolutionary picture. The membrane of organells resemble bacteria in their behaviour and metabolism.
The order of events in evolution is decisive. Corkscrew shaped spirochetes, speedsters of the microbial world, are coiled and snakelike. Through viscous fluids such as mud, slime, mucus and living tissue, these bacteria dart to and fro, up and down, left and right. As they do now, in the remote past they outswam other bacteria. Quick and prolific spirochetes invaded archaebacterial inner space and those that interacted survived. Their living descendents are now inextricably involved in mitotic cell movements and other actions of complex cells.
All cells with mitochondria also have microtubules, remnants of ancient wrigglers. Such structure is consistent with the idea the spirochete- archaebacteria symbiosis was established first. Today certain mitotic swimming cells, to which oxygen is poison, still lack mitochondria. I deduce that the mitotic ancestor to all eukaryotic life evolved before oxygen permeated all corners of the atmosphere.
The Symbiotic Planet
Liquid salt water on Mars is in the form of highly-concentrated brine may support a "salt-loving" type of bacteria, says Geoffrey Landis, a space scientist and science fiction writer at the NASA Glenn Research Center in Cleveland, Ohio. Halobacteria, is a form of extremophile, archaeobacteria, adapted to surviving in saturated salt solutions. It is possible that this ancient bacteria is preserved in salt deposits on the planet.
"Retrieval of ancient life from Mars would answer many questions about the origin of life, and the relationship or independence of Mars and Earth biology," Landis recently reported in the new journal, "Astrobiology".
NASA scientist Chris McKay, suggests that these Martian life forms could be retrieved, then cultivated in a suitable medium for growth back here on Earth.
Posted by Kathleen on September 2, 2006 2:20 PM to Kathleen Rogers