To : Joe Morlan Subj: ADAPTION=EVOLUTION? JM Would it have taken as much time as it took w

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From: David Bushard Posted: 7 Oct 94 00:53 To : Joe Morlan Subj: ADAPTION=EVOLUTION? JM> Would it have taken as much time as it took writing the above JM> paragraph to simply explain that each chromosome is a DNA JM> molecule and each chromosome is different? How about taking a you still don't have it. a chromosome is NOT a dna molecule. you have your scale off by quite a few orders of magnitude. previously you were off by something like 10 or 12 orders; you may now be off by a mere 5 or 6 orders. the correspondence between "gene" and "dna molecule" is probably not one-to- one, but it may be close. a gene may be one molecule, it may be part of a molecule, it may take more than one molecule to comprise a gene, but they are on approximately the same order of magnitude. the theoretical (but VERY unlikely) lower limit on the number of genes per chromosome is one, but the upper limit is at least millions. a chromosome is NOT a dna molucule, any more than a bus is a person. maybe this will help a bit: genes and alleles are conceptual entities. the phenomena of inheritance and genetics can be explained only if there are "particles" of information that behave in certain ways. genes are these particles. there are many millions, probably many billions of different particles, which when combined in a set contain the information that is heritable for a particular organism. this is further complicated by the fact that there may be many different genes that affect the same thing. eye color is a good example, since it behaves so (comparatively) simply. there exists a gene that codes for blue eye color, one for brown, one for hazel (probably), perhaps one for green, one for grey, and maybe one or two more, but in any case a total of at least several. you carry two of them, not all of them. there are other genes elsewhere that may over-ride this, such as those that produce albinism, which would cause your eye color to be red, regardless of the eye-color genes you carry. there may be others that cause the color to be more or less intense, etc. the main point is that in a population there are at least several alleles of the eye- color gene. each of them is "the eye color gene," but there must be some difference or they would be expressed the same. of all possible alleles that exist in the population, an individual will carry (in most cases) two. the exceptions are the sex-linked characteristics, in which males often carry only one copy of particular alleles, and various pathological conditions like down's syndrome and others. all that above was CONCEPTUAL, not necessarily physiological. the exact molecular and/or biochemical and structural basis for the above ideas has been the subject of extremely intense investigation for a long time. watson and crick made one of the most important breakthroughs, but the exact correspondence between DNA molecules and genes is yet to be shown. we know that there is a correspondence, but the mapping is complex. as with many other things, it appears to defy any simple analysis. however, certain things are known about the PHYSICAL basis of genetics: chromosomes carry on them the heritable information. they are organized in pairs, each member of a pair carrying information analogous and homologous to the information on the other of that pair, but NOT the same. furthermore, the chromosomes are NOT the smallest unit of information; they are only the physical entities on which that information is written. think of a chromosome as a book, and the words printed in it as the individual units of information, and you will have the scale conceptually close enough. during the life of a cell (including germ cells) the chromosomes can be disassembled, then reassembled into a pair that still carrys all the same alleles, but grouped differently. (e.g., a child will have info from both parents on each of it's chromosomes, not simply one chromosome from dad and one chromosome from mom, but all information present comes from either dad or mom, except in the case of a mutation.) chromosomes are fairly easily visible structures in the cell. DNA molecules are MUCH MUCH smaller -- they are sub-microscopic in size. being very complex, it is often not clear where one begins and another ends, nor is it clear that each one remains essentially intact, nor is it clear that they do not. it IS clear that they are complex, and that we have a great deal to learn about how they actually behave. this discussion of chromosomes and DNA is not conceptual, it is physical. the correspondence between the concepts and the actual phsical particles is being mapped out. the simple hypotheses, like "a gene is a dna molecule" do not seem to work. JM> I discussed basic cell biology with several colleages at a recent JM> conference and found that I was incorrect. In fact, each JM> chromosome is a DNA molecule wrapped in a protein, and each JM> chromosome is different. i think you misinterpreted what these colleagues told you. JM> Would it have taken as much time as it took writing the above JM> paragraph to simply explain that each chromosome is a DNA JM> molecule and each chromosome is different? How about taking a JM> minute or two to correct what might be a widespread JM> misunderstanding? I'm here to learn, not to win debating points! aside from the egregious error about a chromosome being a dna molecule, it has so far appeared that you have been unwilling to learn some very fundamental ideas. it may be that this has changed. perhaps in the light of the above, you will now understand what john thompson has been trying to explain to you about how probability is exactly the explanation for the irreversibility of speciation. this is just "biology," after all. david --- Maximus 2.01wb * Origin: The Swamp, River Falls WI 715.425.8865 & 612.436.5254 (1:2245/101) From: David Bushard Posted: 7 Oct 94 00:53 To : Joe Morlan Subj: THE RULES JM> to show that the current variation in humans could not possibly JM> have occurred in the short time since the Ark. In fact, small JM> isolated populations and bottlenecks have considerably more JM> evolutionary potential despite their small size because each JM> individual's contribution to the total gene pool is higher. His JM> calculations seemed to ignore this phenomonon. you misunderstand this. the quantity of information present in today's human population -- not any individual, but the population as a whole -- is so hugely larger than the maximum possible in the few on the ark that a change rate very much greater than anything ever observed would be required. there may have been 4 to 14 alleles for a particular gene on the ark, and this would have to translate into, in some cases, thousands of different alleles. 8 people related as those were can carry a max of 14. whence arise the others that are now present? JM> E.g. the recent "Eve hypothesis" claimed that the human JM> population did, in fact, go through such a population bottleneck. this is a common misunderstanding. the eve hypothesis says nothing even remotely similar to this. furthermore, the postulated "eve" would have been at least twenty times farther back than the noah of the fundamentalists. david From: Dr Pepper Posted: 9 Oct 94 18:53 To : David Bushard Subj: ADAPTION=EVOLUTION? > JM> Would it have taken as much time as it took writing the above > JM> paragraph to simply explain that each chromosome is a DNA > JM> molecule and each chromosome is different? How about taking a > you still don't have it. a chromosome is NOT a dna molecule. > you have your scale off by quite a few orders of magnitude. > previously you were off by something like 10 or 12 orders; you > may now be off by a mere 5 or 6 orders. > the correspondence between "gene" and "dna molecule" is probably > not one-to-one, but it may be close. a gene may be one > molecule, it may be part of a molecule, it may take more than > one molecule to comprise a gene, but they are on approximately > the same order of magnitude. the theoretical (but VERY > unlikely) lower limit on the number of genes per chromosome is > one, but the upper limit is at least millions. How about: A gene is a file, a dna molecule is a magnetizable surface, a chromosome is a disk. Mutation is a parity error in data transmission. Junk dna is a consequence of the lack of a defragger. 10 2 DR PEPPER 4 --- From: David Bushard Posted: 14 Oct 94 09:42 To : Dr Pepper Subj: ADAPTION=EVOLUTION? DP> A gene is a file, a dna molecule is a magnetizable DP> surface, a chromosome is a disk. Mutation is a parity DP> error in data transmission. Junk dna is a consequence DP> of the lack of a defragger. DP> DR PEPPER a good analogy -- so good that i thought it would bear some repetition, as above. of course, the total volume of information in a cell approximates the volume of info in the library of congress, so we have to think in magnitudes rather larger than the hard disks most of us have. 11 3 david 5

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