Saturday, February 7, 2015
Absence of evolution? The Discover of microorganism that has not evolved over millions of years.
The new discovery of two microbial biota in the deep waters of Turee Creek and Duck Creek in Western Australia, opens a new window on the early history of life, to discover bacteria that can oxidize sulfur with a length of 2.3 billion years (2.3 Ga).
These bacteria were found permineralized in silica, formed shortly after the great oxidation (2.4 to 2.2 Ga) so these two biota can get an answer to what happened in the Precambrian era where increasing environmental oxygen caused an increase in the production of sulfate and nitrate metabolically usable.
But despite these two biota can provide information on the great oxidation on Earth and how amazing is that comparing microbial morphology of fossil bacteria, also habitat and bacteria organization of "modern" sulfur found on the coast of Chile revealed that these two biota were exactly the same, but with the news that the newly discovered had 2.3 Ga.
Similarities in their habitat
Fig. 1. Fabric biota from the Precambrian era. (A-C) Duck Creek 1. 8 Ga; (D-F) Turee Creek 2.3 Ga (Schopf et al., 2015).
These ecosystems biota are characterized by the presence of large bacterial populations that have the ability to metabolize sulfur, also by a low content of dissolved oxygen, in some parts of the subsurface of the community, is essentially zero. Usually comprise two regions: an anoxic zone below the resting surface consisting similar to an interlaced network of randomly oriented long fabric and commonly microorganisms anaerobic filamentous ≤ 10 microns in diameter.
Similarities in morphology and physiology
Fig. 2. Morphological Comparison between "modern" bacteria with fossil bacteria obtained from Turee Creek (2.3 Ga) and Duck Creek (1.8 Ga) (Schopf et al., 2015).
The marked similarities in morphology microbial, habitat and community organization Precambrian their modern counterparts bacteria show a great adaptation to its environment under the seabed, which has remained essentially unchanged for billions of years.
But really seems incredible that life in this habitat has not changed for almost half of the history of the earth when we see that evolution is evident, although the apparent stagnation of two billion years of duration of the mentioned ecosystems relating to the sulfur cycle, is consistent with Darwinian hypothesis which states that if there is a change in the Physical-Biological environment of a well-adapted ecosystem, all biotic components should remain unchanged, i.e., the key to biology is not evolve unless cause changes in the physical or biological environment.
If you want to know more: http://www.pnas.org/content/early/2015/01/27/1419241112.full.pdf+html?sid=7d2171ae-a42c-4401-9dde-79c5d274d96b