Relevant extracts from my posts of July 1999
By Wolfgang G. Gasser
Re: Knockout blow to neo-Darwinism Despite many contradicting claims, it is a (logical) fact thatabiogenesis is a prerequisite for neo-Darwinism. If abiogenesis canbe proven impossible, the whole neo-Darwinian house of cards foldsup, leaving a lot of valuable stuff for alternative paradigms. The difficulty to refute reductionist abiogenesis lies in the lackof concrete knowledge. The more concrete facts and explanations arebrought forward, the more difficult it becomes for neo-Darwinism tosurvive. Everybody should agree that the common ancestor of terrestrial lifemust have had the capacity of reproducing and the potential of furtherevolving by selection. In order to refute neo-Darwinism, I have toreplace the gaps in knowledge by concrete assumptions concerning theneo-Darwinian Adam. 1) Adam was a bacteria-like creature with a cell wall.2) Adam contained 10 different enzymes consisting of each 100 amino acids.3) The genome of Adam consisted of 10 x 100 x 3 = 3000 nucleotides.4) There were 100 copies of each enzyme within Adam.5) Adam lived in a primordial pond with high proportions of prefabricated amino acids, nucleotides and high energy molecules.6) These nutrient molecules and waste molecules could easily cross the cell wall.7) The cell wall protected Adam from harmful molecules.8) The replication of Adam occurred by a) doubling the number of each enzyme from 100 to 200, b) doubling the genome molecule(s), c) splitting the cell into two equal parts by randomly distributing enzymes and genome molecules to the parts. If we ignore the cell wall, we conclude that 103'000 chemical uphillreactions had to be carried out for Adam to replicate. It is perfectlynatural that the enzymes of very early life on earth could not haveworked as efficiently as the enzymes of modern bacteria. Errorcorrecting mechanisms did not yet exist. So I think it is reasonable to assume that the error rate in buildingchemical bonds was not lower than 1 percent. The task of chainingbuilding blocks correctly by using templates and energy from othermolecules is certainly not trivial. An error rate of 1 percent leadson average to 1'030 errors per replication, 30 of them in thegenome molecules. The assumption that the majority of these errors have no or evenhave positive effects is not reasonable. So even without fatal errorsor dangers from the environment, Adam and his descendants would havedegenerated during every cell division and certainly would havebecome extinct after some generations, unless ... ========================================================================Re: Knockout blow to neo-DarwinismRe: Knockout blow to neo-DarwinismRe: Knockout blow to neo-DarwinismRe: Population======================================================================== Re: Knockout blow to neo-Darwinism What can be accepted as evidence depends on one's own world view.The evidence of the existence of a first human couple from whichwe all descend seemed overwhelming to most European scientists(theologians) some centuries ago. The evidence that a singleliving organism could have survived by replicating in a hostileenvironment of only dead matter is in some respect even morequestionable than the evidence for a first human couple in afunctioning ecosystem. ======================================================================== Re: Knockout blow to neo-Darwinism Simple bacteria turned out to be (almost) as complex as Darwinand his contemporaries thought animals and plants are. One mustnot forget that the complexity of life was once considered so lowthat even spontaneous generation of simple macroscopic organismsseemed reasonable. Autotroph bacteria must be able to carry out a huge numberof different tasks in order to build up functioning copies ofthemselves. The spontaneous generation of one autotroph firstprogenote based on the chemistry of modern bacteria (aminoacids, nucleotides, etc.) or on a related one is virtuallyzero. There must have been some kind of a continuous emergenceof a 'primitive ecosystem' which provided 'food' and madepossible innumerous attempts for the creation of more and moreautonomous cells by enzymes, ribozymes and other molecules. One can compare the formation of cells by enzymes with the formation of complex cities by humans. There never has existed a first city all other cities derive from. There has been a lot of horizontal technological transfer between villages and cities (of different cultures). ======================================================================== Defining Evolution - essay for comment John Wilkins writes: "Even geneticists sometimes hold the sneaking suspicion that evolution is not genetically based, because they observe in small scale a general resistance of organic development to change from the 'norm' or 'wild type'. If any biologist is going to be anti-evolutionist, it will be one who works at the molecular level, such as a molecular geneticist or biochemist." http://www.wehi.edu.au/~wilkins/defevolution.html Can anybody provide me with more information on this "generalresistance of organic development to change from the 'norm'or 'wild type'". By the way, last week I read that bacteria have been detectedbelow hundreds of meters of sediments on the seabed. This finding was so unexpected that at first it was explained by bacterial contamination. It was written in the article that the replication cycle of these bacteria is assumed to be many decades or maybe even hundreds of years, but no explanation was given for this assumption. I suppose it is because of 'food'. If bacteria can only survive by increasing entropy, survival becomes impossible the sooner, the shorter their replication cycles. ======================================================================== Re: ENIGMAs --- predictions and mutations Is there any scientific work having predicted antibiotic-resistantbacteria before the fact? I was rather under the impression thatscientists had been surprised by the emergence of multiple-antibiotic-resistant bacteria in such a short time. If (the enzymes of) bacteria or viruses become resistant to toxinsor drugs then it is explained by the appearance of mutations. Butalso long-living organisms such as animals and plants can getaccustomed to toxins and drugs. Take the case of anti-HIV-drugs.In many cases, HIV positive people develop side effects when theyfirst start taking a new anti-HIV drug, but with time, the sideeffects lessen or even disappear. But when this happens, also HIVoften has become resistant to the drugs. (According to the psychon theory, enzymes of long-living organismscan become resistant to toxins and drugs even without mutations.That's a testable prediction!) If the rate of RANDOM point mutations can vary between 10^-4 and 10^-12(a range over eight orders of magnitude) then almost in every case abeneficial mutation in bacteria and viruses can be called RANDOM. Suppose the case that under certain repeatable conditions a helpfulmutation regularly occurs and is selected for. Suppose further thatthis mutation actually has a substantially higher probability than arandom one. Can such a case refute neo-Darwinism? No. Neo-Darwinistsonly conclude that the region where the mutation occurs has for someunexplained reason an exceptionally high mutation rate. ======================================================================== Re: Theory of Natural Selection VS Reality Darwins theory, also called the theory of natural selection, isonly one possible theory of evolution (or continuous creation) andcertainly not THE theory of evolution of the third millennium. And take into account that selection implies reproduction withrandom mutations (and recombination), and that genetic drift(to-FAQ: "a random change in allele frequencies") is essentiallythe same as selection. Whereas natural selection is based on ahigher reproductive success, genetic drift is based on randomselection. ======================================================================== ENIGMAs --- Innovations vs. Mutations It is generally acknowledged that mutation rates are very differentwithin a single genome. There are genes such as cytochrome-c andubiquitin with a mutation rate of almost zero. Also within genes,regions with high mutation rates are confronted with highlyconserved regions. Around 70 percent of the mutations of the third position of a DNAtriplet are silent. According to Motoo Kimura (Scientific American,11/1979) such positions seem to be especially variable. If theyactually have a higher mutation rate than the first two positionsof triples then neo-Darwinism has a big problem. There are cases where bacterial resistance to an antibiotic dependson one single point mutation. It is very surprising how easy it is foran enzyme that is inhibited by an antibiotic to become an enzyme thathydrolyzes that antibiotic. One single point mutation and the enzymes defends itself by attackingthe aggressor! One single point mutation, and the enzyme carries out in addition toits normal tasks the task of hydrolyzing its own aggressor! One single point mutation resolving all biochemical problems involvedin adding such a complex function to a protein without spoiling itsnormal functions! To explain all this by a lucky conformational change resulting fromthe substitution of one amino acid by another defies common sense,logical reasoning and simple probability estimates. ======================================================================== Re: ENIGMAs --- Innovations vs. Mutations One cannot refute the possibility of directed mutations by a fewexperiments whose results allow a random mutation interpretation. That all or most possible point mutations are regularly triedout with more or less the same probability seems to me merely anunjustified assumption. In a genome consisting of 10^7 base pairs there are each 10^7 possibilities to cut out one, two, three or more base pairs. There are 4 x 10^7 possibilities to insert one base pair, 4^2 x 10^7 to insert two and 4^n x 10^7 possibilities to insert n base pairs. 20^10 x 10^7 = 10^20 possibilities exist for the insertion of a sequence of ten amino-acids. "Hall began working with a system that required two mutations to occur before E. coli could use the sugar salicin. One of the mutations, he documented in a 1988 Genetics article, is so rare in growing cells that he failed to detect it. But plated on salicin, Sal+ revertants appeared after a delay of about 12 days. Their frequency was orders of magnitude greater than expected if the two mutations were occurring independently and spontaneously. Furthermore, the rarer spontaneous mutation happened first. This mutation was excision of an insertion sequence. It was followed relatively quickly by the second mutation, which only then permitted transcription. When salicin was absent, Sal+ revertants had no advantage, and Hall was unable to detect excision mutants." http://www.aaas.org/spp/dspp/dbsr/EVOLUT/goodman.htm (1992) It is always possible to explain away the "apparent" increasedprobability of advantageous mutations by some ad-hoc-hypothesis. "Hall wrote that the problem 'is to explain how selective conditions could increase the frequency of useful mutations without increasing the frequency of mutations at other loci.'" The psychon theory also can explain why genes, even in the case of large populations, do not drift apart into uncountable alleles but rather converge to a few or even to one single allele. It's not selection, it's MUTATION! ========================================================================Re: ENIGMAs --- Innovations vs. Mutations======================================================================== Re: ENIGMAs --- Innovations vs. Mutations Because of the huge number of animals it is impossible to explainby genetic drift the fact that there is only one single allele ofubiquitin in all animals. Drift only works for little populations,but certainly not for all animals if considered as one species. The alternative that every mutation in animal ubiquitin is lethalor harmful enough to disappear by selection seems much moreunreasonable to me than the assumption that (non-silent) mutationsare almost inexistent in ubiquitin. Also the existence of 'hotspots' could suggest the existence of 'cold spots'. Think about the evolution of mankind during the last Million ofyears. The mean age at death was certainly lower than today. Sowe can assume that the average number of children per couple wasten (the less, the better for my argument). We can further assumethat children had on average three mutations actually influencingthe phenotype and that fifty percent of the children diedindependently of their genetic constitution. If the probability that a mutation is harmful is 80 percent, then it is very improbable that mankind could have further evolved, because genetic selection could only act on five children two of which had to survive. If one takes into account all facts and tries to be consistent,then one concludes that the many highly conserved regions ofgenomes cannot be the result of continuous selection, but mustbe the result of low rates of mutations. ======================================================================== Re: ENIGMAs --- Innovations vs. Mutations According to Wesley's page [1] the human cytochrome-c does notdiffer from the one of chimps and according to my biochemistryencyclopedia pigs differ neither from cows nor from sheep. Your six-substitution-rule would result in around 100^6 or 10^80possible selectively neutral alleles of cytochrome-c. You evenclaim that "for the vast majority of proteins, such as cytochrome C,trypsin, haemoglobin, barnase and lactate dehydrogenase it is an_underestimate_" [2]. In any case, the fact that pigs, cows and sheep all have the samecytochrome-c is a huge ENIGMA within neo-Darwinism, I even dare tosay that it's a further knockout blow to pure materialism. Thinkabout the odds! 1444 different alleles can emerge from animal ubiquitin by a singlepoint mutation. The fact that none of these alleles actually can befound (with a reasonable frequency?) in animals must be explainedsomehow. The claim that "drift works in arbitarily large populations" issimply wrong. That genes have converged to only very few or evenone single allele during evolution is an empirical fact. Itsexplanation by genetic drift, however, is rather a typical caseof the "ordinary unintentional scientific dishonesty". ======================================================================== Re: The Death of Neo-Darwinism (was: Molecular Sequence Proof of Common Descent) | However, with DNA sequences there is an extra level of redundancy. The| genetic code itself is redundant; on average there are 3 different| codons (a codon is a triplet of DNA bases) that can specify the exact| same amino acid.|| Thus, for cytochrome c there are 3^104, or over 10^49, different DNA| sequences (and, hence, 10^49 different possible genes) that can specify| the very exact same protein sequence.|| As mentioned above, the cytochrome c proteins in chimps and humans are| exactly the same. The clincher is that the two DNA sequences that code| for cytochrome c in humans and chimps differ by only one codon, even| though there are over 10^49 different sequences that could code for| these two proteins. Because neither selection nor genetic drift can explain that human and chimp [cytochrome c] DNA-sequences did not drift apart by randommutations, neo-Darwinism is definitively dead !!! ======================================================================== Re: ENIGMAs --- Innovations vs. Mutations That the achondroplasia mutation occurs at a rate of about 10^-6and "with a couple of exceptions, always involves a particularnucleotide change and amino acid change" is certainly notconsistent with the principle of random mutations. In a similarway also mutations leading to cancer are far from being totallyrandom! The psychon theory explains substantially increased mutationprobabilities by the existence of psychons corresponding toalternative alleles. In such a way, alleles can survive evenif they lead to death before reproduction. What I write here may seem strange to someone who believes inorthodox materialism, but the psychon thesis leads to lots oftestable predictions (and even to completely new medical methods).For instance it predicts that artificially induced mutationswill mutate back to the original sequence with a substantiallyincreased probability. Assume that the probability for a selectively neutral randommutation in a certain protein is 10^6. If we assume a constantpopulation of 10^9 with one single allele at the respectivelocus in the first generation, we get 10^3 alleles differingfrom the original form in the second generation. After a milliongenerations a huge number of different selectively neutralalleles have appeared and the frequency of the original alleleis reduced to around 37 percent. That's simplest probability theory and cannot be denied in areasonable way. ======================================================================== Re: ENIGMAs --- Innovations vs. Mutations And what about domesticated species becoming wild. After a few generations individuals with reduced domestication traits can appear. How can this happen in a few generations if the necessary mutations do not occur? Also in the case of extremely inbred rats, having undergone prolonged gene purgation, genetic variability can reemerge rather quickly. In my (homozygous) example above, in the second generation 1000new alleles have appeared. Every of these alleles would have atheoretical probability of 10^-9 (inverse of the population size)to reach 'fixation' by drift after a huge amount of generations,only if no more mutations occurred. But in every new generationaround 1000 alleles differing from the most frequent allele doappear. ======================================================================== Re: The Death of Neo-Darwinism (was: Molecular Sequence Proof of Common Descent) | My point was that the hypothesis of common descent predicts that| chimps and humans should have similar DNA sequences, and they do| despite incredible odds. But if the odds are too incredible, then some kind of order-creatingprinciples apart from random mutation and selection must be assumed. ======================================================================== Re: The Death of Neo-Darwinism (was: Molecular Sequence Proof of Common Descent) | When considering your cyt c sequence and your mother's, the exact same| incredible odds are involved - yet we don't "assume" any order-creating| principles, aside from heredity. Over one generation it is certainly not astonishing that DNA sequences remain unchanged. But if sequences do not change over 100'000, 1'000'000, 10'000'000, 100'000'000 or even more generations, your objection becomes unfounded. It is a logical consequence of neo-Darwinism that all possible DNA sequences coding for a given amino acid sequence are equivalent. Therefore this theory predicts the existence of lots of different DNA sequences for a given amino acid sequence (and in addition to that also the existence of lots of more or less functionally equivalent alleles for all gene loci). ======================================================================== Richard Harter's demolition of modern synthesis | The catch is that there aren't enough genes. The human genome has| approximately 70,000 genes. If genes are to determine traits| quasi-continuously it will take 10-20 genes to control one trait which| means that the number of traits controlled by the genome is on the order| of 5,000 traits OR LESS.|| The observation that genes affect many traits and vice versa is not| cogent; the issue is one of degrees of freedom. Likewise appeals to| self-organization are not to the point; self-organization can elaborate| the effects of genes but the variation must be supplied by the genome.|| It is relevant to point out that a gene on average consists of a| thousand base pairs, thereby supplying many bits of information.| However most of this supply of information is a mirage. The vast bulk| of a protein is devoted to folding up into the right shape. The region| of interest is the hot spot which only consists of a handful of amino| acids. It should also be noted that a fair percentage of the genome is| devoted to house-keeping machinery for the eukaryote cell.|| The problem then is that a few thousand (or less) evolvable traits is| not enough to account for the evolution of the morphology of human| beings and our fellow vertebrates. It does seem to be true that the| synthesis accounts for the evolution of bacteria (and presumably the| monera) - the number of traits to be governed is much smaller and the| effects of the genome are strictly localized. However the synthesis was| developed to account for the evolution of the metazoa and the metaphyta*| in terms of population genetics and this, manifestly, is what it does| not do. | Look at beak size in those finches, for instance -- it's variation that| can be quantified with a few simple parameters, but all the underlying| biology is a total mystery. ======================================================================== Re: The Death of Neo-Darwinism (was: Molecular Sequence Proof of Common Descent) There have been a lot of innovations in humans after their separationfrom chimps several hundred thousand generations ago. If all what makesus different from chimps depends on random mutations and selection thenmutations must occur with a certain frequency. But if not even themany possible neutral mutations leaving amino acid chains unchangedoccur then it becomes highly improbable that mutations are the primarycause of evolution or at least that mutations are random. ======================================================================== Re: The Death of Neo-Darwinism (was: Molecular Sequence Proof of Common Descent) We cannot explain the evolution of humans after their separationfrom chimps by the same means as the evolution of bacteria. As Ihave already stated in another post, it is not very likely thatnatural selection could have acted on more than five births percouple per generation, because many deaths are unrelated toDarwinian fitness. Neo-Darwinism states that random mutations are the primary causeof human evolution. So almost all deleterious mutations must be soharmful that concerned gametes do not lead to pregnancy (or resultin early spontaneous abortion), and the remaining (slightly)harmful mutations in new-born must not be substantially morefrequent than (slightly) beneficial mutations. Two beneficial point mutations per generation affect 4 bits andafter 300'000 generations 150'000 bytes have been beneficiallychanged. Can this account for all the differences between chimpsand child prodigies (e.g. chess, piano)? I don't think so. In addition to that, the two beneficial mutations per generationmust spread over the whole population by selection whereas atthe same time deleterious mutations must disappear by selection.Is this a realistic scenario? I don't think so. Remember, all biological innovations of human evolution are said to derive from random mutations. The proportion of beneficial to deleterious mutations is therefore a crucial factor. If "there are still 10^45 genuinely functionally and phenotypicallyequivalent DNA coding sequences" [for cytochrome c] then one must not take it for granted that the common ancestors of chimps and humans used only one single version of more than 10^40 possibilities. There is also no obvious reason within neo-Darwinism why most (all?) humans share one version and most (all?) chimps share another one. NEO-DARWINISM DOES REMAIN DEAD because it predicts either huge numbers of functionally equivalent alleles and coding sequences or so many constraints on non-deleterious mutations that evolution becomes impossible (at least in the case of species having long replication cycles).