Comments on: Coevolution with viruses drives the evolution of bacterial mutation rates http://henry.simon.net.nz/stories/2007/12/12/coevolution-with-viruses-drives-the-evolution-of-bacterial-mutation-rates/ cultural evolution news Fri, 04 Jun 2010 09:25:12 +0000 hourly 1 http://wordpress.org/?v=abc By: Dave Finn http://henry.simon.net.nz/stories/2007/12/12/coevolution-with-viruses-drives-the-evolution-of-bacterial-mutation-rates/comment-page-1/#comment-64 Dave Finn Wed, 19 Dec 2007 21:26:37 +0000 http://henry.simon.net.nz/stories/2007/12/12/coevolution-with-viruses-drives-the-evolution-of-bacterial-mutation-rates/#comment-64 First rule of science - do the mathematics. If you calculate the values of the supposed "disadvantages of mutation" over all values of probability of survival and not only the stable normal range you will note that at low rates of survivability (caused by phages, or anything else) the disadvantages of mutation become progressively smaller until they are smaller than the advantages. Hence any organism that treats being pushed to the limits of extinction as a stimulus to increased mutation will tend to gain advantages and leave more descendants - which is the ultimate test in evolution. Active mutation, as opposed to the passive forms considered in the popular but essentially irrelevant neo-Darwinian theories, is subject to natural selection. The organisms that mutate most appropriately in response to a specific stress gain most advantage and leave most descendants. After a few billion years of selection the forms of active mutation utilised by bacteria are spectacularly more effective at producing genetic novelties appropriate to the presenting problems than any form of random mutation. Evolution of species is also an active process. A thriving population of a species is under no pressure to evolve, it is only the failing species that have to evolve or become extinct. Since the failing species have an example before them, the thriving species, of a genome that is more appropriate to the (presumably changed) environment there is no difficulty in determining the preferred direction of evolution. All that is required is a mechanism, and this is provided by lateral gene transfer - the acquisition by a species which cannot survive in a given environment of genes from a species that can. First rule of science – do the mathematics. If you calculate the values of the supposed “disadvantages of mutation” over all values of probability of survival and not only the stable normal range you will note that at low rates of survivability (caused by phages, or anything else) the disadvantages of mutation become progressively smaller until they are smaller than the advantages. Hence any organism that treats being pushed to the limits of extinction as a stimulus to increased mutation will tend to gain advantages and leave more descendants – which is the ultimate test in evolution. Active mutation, as opposed to the passive forms considered in the popular but essentially irrelevant neo-Darwinian theories, is subject to natural selection. The organisms that mutate most appropriately in response to a specific stress gain most advantage and leave most descendants. After a few billion years of selection the forms of active mutation utilised by bacteria are spectacularly more effective at producing genetic novelties appropriate to the presenting problems than any form of random mutation.

Evolution of species is also an active process. A thriving population of a species is under no pressure to evolve, it is only the failing species that have to evolve or become extinct. Since the failing species have an example before them, the thriving species, of a genome that is more appropriate to the (presumably changed) environment there is no difficulty in determining the preferred direction of evolution. All that is required is a mechanism, and this is provided by lateral gene transfer – the acquisition by a species which cannot survive in a given environment of genes from a species that can.

]]> By: links for 2007-12-13 « Chatquah and Galoshes http://henry.simon.net.nz/stories/2007/12/12/coevolution-with-viruses-drives-the-evolution-of-bacterial-mutation-rates/comment-page-1/#comment-63 links for 2007-12-13 « Chatquah and Galoshes Thu, 13 Dec 2007 15:19:01 +0000 http://henry.simon.net.nz/stories/2007/12/12/coevolution-with-viruses-drives-the-evolution-of-bacterial-mutation-rates/#comment-63 [...] Bacteria mutates more quickly when with viruses (especially phages) (tags: biology evolution science technology) [...] [...] Bacteria mutates more quickly when with viruses (especially phages) (tags: biology evolution science technology) [...]

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