>> Epigenetic changes show that there is more to hereditary information than base pair sequence. Which I find to be fascinating in and of itself. It also begs the question: Are there any other as yet to be discovered encoding schemas that can be faithfully transmitted across hereditary boundaries? There are at least three hereditary capable encoding schema, e.g. DNA, RNA (RNA viruses as an example), and now also various epigenetic mechanisms (not just methylation mechanisms, but also histone modification and perhaps other means as yet to be discovered). Is this it? Or are there other means in addition to these? I understand why life would have soon discovered the need for (or perhaps great convenience of) developing this second more dynamic and more reversible level of encoding that operates on top of the underlying DNA, in order to be able to finesse the basic instruction set and make it do double, triple or even more duties. How important doing so is for living things can be understood by looking at the process of embryogenesis in complex animals (and plants as well, where epigenetics plays a role in the early maturation process of a plant form potentiated seed to the young but recognizably formed plant) Even post transcription the genetic expression chain is still being modified and regulated by dynamic processes along the way; mechanisms such as for example: autophagy, microRNAs, and ubiquitinization, which all regulate embryo development post-transcriptionally. Can we exclude that this highly dynamic complex of expression regulation stops there? What about in the Ribosomes themselves? Is it just a copy machine faithfully generating amino-acid chains based on the form of the mRNA template it is given; or does the dynamic cellular expression regulation mojo reach all the way down into our cell's protein factories? Why so many various expression regulation mechanisms in the first place? I suspect this gives a clue to the underlying dynamic equilibrium of living things and just how complex and finely tuned a balance life must be. Providing a static DNA blueprint does not suffice and so life has evolved these more dynamic mechanisms to regulate expression along -- each step on the chain that we look at. And now we are discovering that some of these more dynamic expression regulation mechanisms are capable of exerting hereditary influences on organisms yet to be born. -Chris
________________________________ From: Russell Standish <li...@hpcoders.com.au> To: everything-list@googlegroups.com Sent: Tuesday, August 13, 2013 6:12 PM Subject: Re: Serious proof of why the theory of evolution is wrong On Tue, Aug 13, 2013 at 12:01:52PM -0400, John Clark wrote: > On Mon, Aug 12, 2013 Russell Standish <li...@hpcoders.com.au> wrote: > > > The central dogma of molecular biology deals with the detailed > > residue-by-residue transfer of sequential information. > > > Yes, but we're not talking about molecular biology, we're talking about > Evolution and it has a different central dogma. > > > > > It states that such information cannot be transferred back from protein > > to either protein or nucleic acid. > > > I know of no example of a change in a protein making a systematic > repeatable change (as opposed to a random mutation) in the sequence of > bases in DNA that are passed onto the next generation. > Epigenetic information is expressed by the presence or absence of methylation of the bases, not the sequence. > > Not all evolutionary processes have the central dogma > > > > So what? As I said before, Darwin knew nothing about DNA or proteins or > epigenetic changes and he didn't need to; he knew nothing about the details > he only knew that there were hereditary factors of some sort that were > passed from one generation to the next, and because no process is perfect > he knew that there would sometimes be changes in that information, and he > knew that some of those factors would reproduce faster than others, and he > knew that the thing that would determine the winning factors from the > losing factors is natural selection. > Sure, I'm not arguing that epigenetic, prebiotic or cultural evolution shouldn't be called "Darwinian". But in that case, Lamarkian evolution is also "Darwinian", and sometimes people want to draw that distinction, so the adjective "Darwinian" become a bit ill-defined and meaningless. Any process satisfying Lewontin's 3 criteria I would call evolution. If any of the criteria are not satisfied, I would use a word like "process", such as "irreversible process", or whatever. > > > > What it means is that lessons learnt by the body (ie protein) cannot be > > transferred back to the genome (ie DNA). It is the antithesis to > > Lamarkianism. Epigenetic changes involve changes of the genome by the body > > > Epigenetic changes do not change the sequence of bases in DNA, and more > important I see no evidence that the body has learned any lessons. I see no Epigenetic changes show that there is more to hereditary information than base pair sequence. > evidence that epigenetic changes are more likely to happen in the direction > of greater adaptability rather than the reverse. All I see is the > environment causing random changes in hereditary factors that, like all > changes, are more likely to be harmful than helpful. > > > > > How significant epigenesis is to evolution is another matter, of course. > > > > Well Darwinian Evolution was what we are talking about! Well, actually, what we started talking about was prebiotic evolution, the possibility of evolving an oprimised standard genetic code, to be precise. > At most all > epigenesis does is provide a new source of variation for Darwinian Natural > Selection to work on; and if those changes don't persist through many > generations then epigenesis can't even do that. > > > Obviously, there is no equivalent central dogma in cultural evolution. > > > > The central dogma of Evolution, both biological and cultural, has nothing > to do with DNA or proteins or epigenesis. The central dogma of Evolution is: > > 1) Heredity factors exist. > 2) The process that transfers those factors is very reliable but is not > perfect and so sometimes they change. > 3) Because there are more ways to be wrong than to be right most (but not > all) of those changes are harmful. > 4) Some of those changed heredity factors will reproduce faster than > others and become dominant in a population. > Provide one citable source where the author uses the term "central dogma" to describe the above (which is a somewhat poor paraphrase of Lewontin's 3 criteria of evolution). > The discovery of epigenesis does not in any way challenge the central dogma > of Evolution. > Only if you redefine the term "central dogma" to mean something else entirely, my Humpty! -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au/ ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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