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Richard Dawkins discusses this in his book The Greatest Show on Earth: The Evidence for Evolution Bacteria and other microorganisms, specifically Archaea, are able to exchange in a sort of 'copy and paste' genetic exchange that differs wildly from sexual reproduction. They can even exchange genes with other distantly related species. This, coupled with ...


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I'm not sure I understand the question. You've elegantly demonstrated that only a tiny fraction of all protein sequences could possibly exist, but then asked why only a tiny fraction of all protein sequences do exist. Your conclusions about independent origins of life having no proteins in common are accurate, but also consider that you as a human being have ...


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The answer is chance or, even better, contingency. About your calculations, it is true that the theoretical sequences are almost unlimited, but the basic scaffolds are not. Very different sequences can fold into the same basic scaffold and have a similar reactivity/function. So, even if not all the sequences have been explored on this planet, most of the ...


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http://www.livescience.com/46986-human-genome-junk-dna.html Microorganisms are often able to adapt to new environments quickly, but they lack the specialized functions of macro-organisms. Consider that the micro-organisms of macro-organisms have developed to form machinery that builds solutions to problems, rather than being retrofitted themselves to ...


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His notion of systemic mutations involved the postulation of massive chromosomal rearrangements (not mere recombination/crossing-over) as mediators of speciation in one-step. While whole genome duplications have been shown to induce speciation (see, for example, cryptic speciation in Hyla versicolor) they are not large scale rearrangements as he suggested. ...


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According to this wiki page , the average background radiation is 3.01 milli-Sievert per year (including natural and artificial sources). This equals 0.301 rad. I found a short letter to nature that says the average forward mutation rate in human is 2.6 * 10^-7 per locus per rad = 2.6 mutations per ten million bases. Also it say that this mutation rate is ...


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It is not essentially asexual reproduction that causes mutations. Mutations can be caused because of errors in DNA replication which can happen during both mitosis and meiosis. Mutations can also be caused because of error-prone DNA repair mechanism. Other than these intrinsic factors there are physical and chemical mutagens that alter the DNA or ...


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It is possible but extremely unlikely. When a base undergoes tautomeric shift the DNA does not contain a mutation yet, just an unmatched pair. The mutation will only becomes inscribed into the DNA permanently after the DNA is replicated or wrongly repaired. In order to reverse the mutation you would need to provoke a chemical change to that specific base ...


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Lets assume for simplicity that DNA is globally subjected to the same mutation rate (which is probably not a fully correct assumption). Now let take a DNA region which is functional (what you meant by giving a fitness benefit), mutations in this region will occur as anywhere else in the genome. Some mutations will be deleterious and reduce the fitness of ...



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