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Member (Idle past 1419 days) Posts: 1495 From: Framingham, MA, USA Joined: |
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Author | Topic: The Importance of Potentially Disconfirming Evidence | |||||||||||||||||||
Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Oh well, to bad they do...at its most basic level, every mutation is a punctuated event..in any case Science. 1996 Jun 21;272(5269):1802-4. Related Articles, Links Comment in:Science. 1996 Dec 6;274(5293):1748-50. Science. 1996 Jun 21;272(5269):1741. Punctuated evolution caused by selection of rare beneficial mutations. Elena SF, Cooper VS, Lenski RE. Center for Microbial Ecology, Michigan State University, East Lansing, 48824, USA. selena@ant.css.msu.edu For more than two decades there has been intense debate over the hypothesis that most morphological evolution occurs during relatively brief episodes of rapid change that punctuate much longer periods of stasis. A clear and unambiguous case of punctuated evolution is presented for cell size in a population of Escherichia coli evolving for 3000 generations in a constant environment. The punctuation is caused by natural selection as rare, beneficial mutations sweep successively through the population. This experiment shows that the most elementary processes in population genetics can give rise to punctuated evolution dynamics. There are dozens of other references to exactly this topic...which..drum roll please, are actually supported by observation and experimental evidence...can't say that for the "I don't understand it so it must have been designed" crowd...oh well
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Spare you what? You have clearly spared an education in genetics. Do you think a genetic mutation is a punctuated or a gradual event? Is a retrotranposon insertion punctuated or gradual over generations...think about it.
quote: You claimed that punk eek is not observed genetically, the reference (which you did not read) shows you are wrong...at the end of this post are 7 additional references including one that shows a genetic barrier developing between bacteria i.e. new species via mutation and selection. So no, the new bacteria are not just E. coli anymore.
quote: I have already seen what they contain...we will see if you will. Note the first reference is a review in case the science in those "peer reviewed rags" I believe you call them, go over your head 1: Elena SF, Lenski RE. Related Articles, LinksEvolution experiments with microorganisms: the dynamics and genetic bases of adaptation. Nat Rev Genet. 2003 Jun;4(6):457-69. Review. PMID: 12776215 [PubMed - indexed for MEDLINE] 2: Lenski RE, Ofria C, Pennock RT, Adami C. Related Articles, Links The evolutionary origin of complex features. Nature. 2003 May 8;423(6936):139-44. PMID: 12736677 [PubMed - indexed for MEDLINE] 3: Lenski RE, Winkworth CL, Riley MA. Related Articles, Links Rates of DNA sequence evolution in experimental populations of Escherichia coli during 20,000 generations. J Mol Evol. 2003 Apr;56(4):498-508. PMID: 12664169 [PubMed - indexed for MEDLINE] 4: Cooper TF, Rozen DE, Lenski RE. Related Articles, Links Parallel changes in gene expression after 20,000 generations of evolution in Escherichiacoli. Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):1072-7. Epub 2003 Jan 21. PMID: 12538876 [PubMed - indexed for MEDLINE] 5: Vulic M, Lenski RE, Radman M. Related Articles, Links Mutation, recombination, and incipient speciation of bacteria in the laboratory. Proc Natl Acad Sci U S A. 1999 Jun 22;96(13):7348-51. PMID: 10377417 [PubMed - indexed for MEDLINE] 6: Papadopoulos D, Schneider D, Meier-Eiss J, Arber W, Lenski RE, Blot M. Related Articles, Links Genomic evolution during a 10,000-generation experiment with bacteria. Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3807-12. PMID: 10097119 [PubMed - indexed for MEDLINE] 7: Velicer GJ, Kroos L, Lenski RE. Related Articles, Links Loss of social behaviors by myxococcus xanthus during evolution in an unstructured habitat Proc Natl Acad Sci U S A. 1998 Oct 13;95(21):12376-80. PMID: 9770494 [PubMed - as supplied by publisher]
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
Oh yeah, and since I will assume you will just brush off all bacterial data as irrelevant, here are several other completely different organisms where studies of the genetics of speciation have been undertaken...but since you claimed that ID looks at all the "current knowledge" in deriving its conclusions..I guess you must have read all of these studies and the dozens of others that have also been undertaken?
Maybe you could point me to a genetic study that provides evidence for ID? Proc Natl Acad Sci U S A. 2004 Jun 7 [Epub ahead of print] Related Articles, Links Early events in speciation: Polymorphism for hybrid male sterility in Drosophila. Reed LK, Markow TA. Department of Ecology and Evolutionary Biology and Center for Insect Science, University of Arizona, Tucson, AZ 85721. Capturing the process of speciation early enough to determine the initial genetic causes of reproductive isolation remains a major challenge in evolutionary biology. We have found, to our knowledge, the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. Specifically, we show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, Drosophila arizonae, is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, we show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring. Because male sterility factors in hybrids between these species are not yet fixed within D. mojavensis, this system provides an invaluable opportunity to characterize the genetics of reproductive isolation at an early stage. Mol Phylogenet Evol. 2003 Dec;29(3):507-18. Related Articles, Links Genes that determine flower color: the role of regulatory changes in the evolution of phenotypic adaptations. Durbin ML, Lundy KE, Morrell PL, Torres-Martinez CL, Clegg MT. Department of Botany and Plant Sciences, University of California, 2213 Batchelor Hall, Riverside, CA 92521, USA. mary.durbin@ucr.edu A central goal of evolutionary genetics is to trace the causal pathway between mutations at particular genes and adaptation at the phenotypic level. The proximate objective is to identify adaptations through the analysis of molecular sequence data from specific candidate genes or their regulatory elements. In this paper, we consider the molecular evolution of floral color in the morning glory genus (Ipomoea) as a model for relating molecular and phenotypic evolution. To begin, flower color variation usually conforms to simple Mendelian transmission, thus facilitating genetic and molecular analyses. Population genetic studies of flower color polymorphisms in the common morning glory (Ipomoea purpurea) have shown that some morphs are subject to complex patterns of selection. Striking differences in floral color and morphology are also associated with speciation in the genus Ipomoea. The molecular bases for these adaptive shifts can be dissected because the biosynthetic pathways that determine floral pigmentation are well understood and many of the genes of flavonoid biosynthesis have been isolated and extensively studied. We present a comparative analysis of the level of gene expression in Ipomoea for several key genes in flavonoid biosynthesis. Specifically we ask: how frequently are adaptive shifts in flower color phenotypes associated with changes in regulation of gene expression versus mutations in structural genes? The results of this study show that most species differences in this crucial phenotype are associated with changes in the regulation of gene expression. Evolution Int J Org Evolution. 2003 May;57(5):1049-60. Related Articles, Links Reproductive character displacement and the genetics of gamete recognition in tropical sea urchins. Geyer LB, Palumbi SR. Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA. lgeryer@oeb.harvard.edu Reproductive character displacement occurs when sympatric and allopatric populations of a species differ in traits crucial to reproduction, and it is commonly thought of as a signal of selection acting to limit hybridization. Most documented cases of reproductive character displacement involve characters that are poorly understood at the genetic level, and rejecting alternative hypotheses for biogeographic shifts in reproductive traits is often very difficult. In sea urchins, the gamete recognition protein bindin evolves under positive selection when species are broadly sympatric, suggesting character displacement may be operating in this system. We sampled sympatric and allopatric populations of two species in the sea urchin genus Echinometra for variation in bindin and for the mitochondrial cytochrome oxidase I to examine patterns of population differentiation and molecular evolution at a reproductive gene. We found a major shift in bindin alleles between central Pacific (allopatric) and western Pacific (sympatric) populations of E. oblonga. Allopatric populations of E. oblonga are polyphyletic with E. sp. C at bindin, whereas sympatric populations of the two species are reciprocally monophyletic. There is a strong signal of positive selection (P(N)/P(S) = 4.5) in the variable region of the first exon of bindin, which is associated with alleles found in sympatric populations of E. oblonga. These results indicate that there is a strong pattern of reproductive character displacement between E. oblonga and E. sp. C and that the divergence is driven by selection. There is much higher population structure in sympatric populations at the bindin locus than at the neutral mitochondrial locus, but this difference is not seen in allopatric populations. These data suggest a pattern of speciation driven by selection for local gamete coevolution as a result of interactions between sympatric species. Although this pattern is highly suggestive of speciation by reinforcement, further research into hybrid fitness and egg-sperm interactions is required to address this potential mechanism for character displacement. Evol Dev. 2003 May-Jun;5(3):269-80. Related Articles, Links Mimicry: developmental genes that contribute to speciation. Naisbit RE, Jiggins CD, Mallet J. The Galton Laboratory, Department of Biology, University College London, London NW1 2HE, UK. russell.naisbit@unine.ch Despite renewed interest in the role of natural selection as a catalyst for the origin of species, the developmental and genetic basis of speciation remains poorly understood. Here we describe the genetics of Mullerian mimicry in Heliconius cydno and H. melpomene (Lepidoptera: Nymphalidae), sister species that recently diverged to mimic other Heliconius. This mimetic shift was a key step in their speciation, leading to pre- and postmating isolation. We identify 10 autosomal loci, half of which have major effects. At least eight appear to be homologous with genes known to control pattern differences within each species. Dominance has evolved under the influence of identifiable "modifier" loci rather than being a fixed characteristic of each locus. Epistasis is found at many levels: phenotypic interaction between specific pairs of genes, developmental canalization due to polygenic modifiers so that patterns are less sharply defined in hybrids, and overall fitness through ecological selection against nonmimetic hybrid genotypes. Most of the loci are clustered into two genomic regions or "supergenes," suggesting color pattern evolution is constrained by preexisting linked elements that may have arisen via tandem duplication rather than having been assembled by natural selection. Linkage, modifiers, and epistasis affect the strength of mimicry as a barrier to gene flow between these naturally hybridizing species and may permit introgression in genomic regions unlinked to those under disruptive selection. Mullerian mimics in Heliconius use different genetic architectures to achieve the same mimetic patterns, implying few developmental constraints. Therefore, although developmental and genomic constraints undoubtedly influence the evolutionary process, their effects are probably not strong in comparison with natural selection.
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Sure it does. You creos argue that accumulated mutation events cannot lead to speciation gradually. The genetic evidence clearly shows that genetic barriers can arise even after a few thousand generations within a species i.e. speciation. This has been observed in multicellular organisms as well. Bacteria illustrate the genetics of this phenomenon over thousands of generations that cannot be observed in longer lived animals directly. According to you,we are supposed to accept that over even more generations, no more diversity and distinction will occur among species and that somehow somewhere without any evidence there was just poof bang creation ex nihilo? That the mechanisms that operate in all living organisms (even those observed over thousands of generations)..or hundreds if you look at ancient DNA, at some point did not operate in the past and was just spontaneously designed? You cannot provide evidence or even a testable hypothesis of design in the present much less extrapolate to the past. If anyone needs evidence it is your camp. But you know what? I am always up for a good hypothesis. Can you provide1. a testable hypothesis of design 2. that is falsifiable? If you can you will be the first to do so
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Creationists have been researching how genetic imprinting can cause mating incompatibility? They sure keep their "understanding" well guarded from the rest of the world then. ...and Linnaen classification system does not rely on any creationists beliefs as like any classification system, it can be used or modified irrespective of ones religious background or lack thereof..Newtonian mechanics were a product of methodological naturalism regardless of any supernatural beliefs Newton held...or do you think you have to be a jew for the theory of relativity to apply?
quote:Yes
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: Show how anything about Mendelian genetics relies on creationionism or any other supernatural explanation....it is pure methodological naturalism regardless of Mendels religious beliefs. Hindu's, atheists, Buddhists, Muslims, Wiccans, you name it have made novel discoveries in genetics, developmental biology, etc. all conected together by methodological naturalism.
quote: You are confusing motivation with actual practice. Again show how classification, taxonomy, cladistics or phylogenetics rely on anything but natural observation or explanation.
quote: Again, you confuse motivation with practice. There is nothing supernatural about Newtons theories. His science was plain old methodological naturalism. Methodological naturalism can be practiced by the religious or the non-religious to advance scientific knowledge. Proposing supernatural causes for natural events has never lead to a single scientific discovery or advancement.
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: And what does this have to do with the classification system? Kerry Mullis claims to have thought up PCR while completely stoned and driving along the freeway. Yet, PCR was realized by application of methodological naturalism...not by consumption of drugs. Lots of people go into medical research because a loved one had a disease. Are all medical discoveries caused by disease? By your logic yes. You need to learn to separate motivation from practice.
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Mammuthus Member (Idle past 6501 days) Posts: 3085 From: Munich, Germany Joined: |
quote: And none of this relies on the supernatural in its conception or application
quote: And like other taxonomists of his time, he was wrong...still has no impact or influence on the classification system.
quote: He could have believed that a talking goat lived in his butt, it is irrelevant to the science of taxonomy.
quote: Which is why modern taxonomy uses his nomenclature system and his observations of the biodiversity in nature but does not rely on mid 18th century superstition.
quote: Kind of screws over his belief in special creation and the fixity of species.
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