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Garrick
14-04-16, 00:42
Microbes Drive Evolution of Animals and Plants: the Hologenome ConceptEugene Rosenberg, Ilana Zilber-Rosenberg

http://mbio.asm.org/content/7/2/e01395-15.full

The hologenome concept of evolution postulates that the holobiont (host plus symbionts) with its hologenome (host genome plus microbiome) is a level of selection in evolution. Multicellular organisms can no longer be considered individuals by the classical definitions of the term. Every natural animal and plant is a holobiont consisting of the host and diverse symbiotic microbes and viruses.

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The major arguments for considering the holobiont as a level of selection are the following.



All multicellular organisms contain abundant and diverse microbiota. Often, the number of microbial cells and the sum of their genetic information are above that of their host.



Not only the host genome but also the microbiome can be transmitted between generations with reasonable fidelity and thus maintains the unique properties of the holobiont.



Microbiotas and their hosts interact in a manner that affects the fitness of the holobiont in many ways, including its morphology, development, behavior, physiology, and resistance to disease. Taken together, these interactions characterize the holobiont as a single and unique biological entity .



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Prior to the formulation of the hologenome concept, genetic variation in animal and plants was assumed to occur exclusively as a result of genetic changes during sexual reproduction, chromosome rearrangements, and epigenetic changes and ultimately by mutation in the host. However, in holobionts, three additional processes can occur: microbial amplification or contraction, acquisition of novel microbial strains from the environment, and horizontal gene transfer (HGT). These three processes can occur rapidly and, as we describe in the next section, are important processes in the evolution of animals and plants.

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Newer discoveries made that Darwinian theory is obsolete.

Why horizontal gene transfer is bad news for darwinism

http://www.uncommondescent.com/intelligent-design/why-horizontal-gene-transfer-is-bad-news-for-darwinism-2/

Evolution: Charles Darwin was wrong about the tree of lifehttps://www.theguardian.com/science/2009/jan/21/charles-darwin-evolution-species-tree-life

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Vertical vs Horizontal Gene Transfer

http://ib.bioninja.com.au/_Media/horizontal-gene-transfer_med.jpeg


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The Role of Horizontal Gene Transfer in Evolution

http://www.actforlibraries.org/the-role-of-horizontal-gene-transfer-in-evolution/

The implications of a wider occurrence of horizontal gene transfer than was previously thought are creating much controversy amongst evolution theorists. For instance, phylogenetic trees, popularized by Charles Darwin in his major work “The Origin of Species” illustrate the genetic relationships between species. They are, however, based on the premise that vertical gene transfer is and always has been the critical factor in speciation and that all forms of life on Earth derived from one single common ancestor. Darwinian evolution theory also necessitates isolation of species in order for new species to develop. Horizontal gene transfer challenges the foundations of these long held beliefs, presenting a plethora of scenarios from which new, often conflicting theories have arisen.

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According current knowledge Darwin's theory is not adequate more.

Newer discoveries challenge old theories but they are exciting and and teach us to an entirely different way of looking at the organisms and evolution.

LeBrok
14-04-16, 05:34
Yep, it is more complicated and complex environment for life and life itself that we expected. All mixing and mixing and mixing and living together, living in each other, and eating each other, and so on. I'm just surprised that it still works, lol. What can I say, Life Will Find a Way.