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Archive-name: talk-origins/creation/part2
Posting-Frequency: monthly Last-modified: 17 May 1998 Version: 3.2 URL: http://www.zeta.org.au/~jeffcox/creation.html The talk.origins FAQ (Creation) Homepage See reader questions & answers on this topic! - Help others by sharing your knowledge [18] Does evolution contradict the bible? [A] Yes. The bible states in Genesis Chapter 1 that God created plants and animals "according to their kind" and this phrase is repeated a number of times. Thus the bible states that God created different kinds of plants and animals and evolution contradicts this. [19] Is natural selection evidence of evolution? [A] No. One well known example of natural selection was observed in populations of _Biston betularia_, the peppered moth. Individuals of this species may be dark or light in colour. Records of moths collected last century show that near Manchester in the North of England around 1% of individuals of this moth species were dark and 99% were light coloured in 1848, and that by 1898 95% of the moths were dark with only 5% light coloured. The moth population changed because pollution from industry killed the light coloured lichens that had previously grown on trees trunks and blackened the trees so that light coloured moths in later years were more easily seen by birds. Since dark moths were less likely to be eaten, they produced more offspring and the dark form of the moth colour gene became more common in the moth population. The dark moths were much more common in 1898 but they were no different to the dark moths that had been alive 50 years earlier. This change in the frequency of existing alleles in the gene pool of the moth population is definitely an example of natural selection and definitely not an example of evolution if evolution is defined in a way that is similar to what it means. The term evolution has been used in Biology for more than a century to include large scale changes that are suggested as an explanation for the origin of all species as a result of natural processes, this usage includes the appearance of novel characteristics and precedes the current definition. [20] What is the difference between natural selection and evolution? [A] Natural selection involves changes in existing species in response to changes in the frequency of existing alleles in the gene pool of the species. It is likely that this type of change happened in the past because similar changes are observed today. Natural selection resulting from changes in the frequency of unaltered existing alleles cannot produce novel characteristics, natural selection has been observed to act on alleles that have very minor changes in base sequence produced by mutations however these minor changes are insufficient to explain the development of novel characteristics. Novel characteristics in organisms such as a change from invertebrates to vertebrates clearly require many new genes with many different Nitrogen base sequences to those in ancestral organisms and it is assumed by evolutionary biologists that mutations produced the novel genetic material. This genetic change is different in kind to the change in the frequencies of existing alleles that are produced by natural selection. There are questions regarding large scale change that do not apply to natural selection as a result of existing allele frequency changes, for example the relative rates of beneficial and deleterious mutations, the origin of new characteristics that require many genes, and the development of multiple step processes. Despite these differences, modern examples of natural selection are claimed to provide support for, or according to some, proof of large scale evolution. This is not sound logic because although natural selection acting on mutations has been observed to produce modifications to existing characteristics it has not been shown to produce novel characteristics. Proof of a simple process is not proof of a more complex process that includes the simpler one. To suggest that the variation among Galapagos finches was produced by these processes is extrapolating beyond the data, to say that vertebrates were produced from invertebrates by these processes is a guess. [21] Some mutations have been shown to produce changes in multicellular organisms that appear to be beneficial. Does this show that evolution could have happened? [A] No. Mutations that turn off a gene may produce altered characteristics that may be beneficial in some cases. Any one of a large number of possible changes to the DNA of the gene could produce this outcome by damaging the gene, or the section of DNA that regulates the expression of the gene may be altered. Some single base substitution mutations may also produce characteristics that may be beneficial in some cases. These mutations are very different to the formation of a novel gene with a number of bases in the sequence that are not found in the base sequences of existing genes, and the evolution of very different kinds of organisms that have novel characteristics would require genes with many base sequences that are different to those of previously existing genes. Many of the new genes (*or duplicated genes that are significantly altered) that are required for large scale change would need to have been produced either by many separate base substitution mutations or by DNA strand rearrangements where a section of DNA containing a number of bases is inserted into a chromosome to produce a novel gene with a number of novel bases. Such mutations are _very_ unlikely since novel genes will in many cases require base sequence changes from existing genes at more than one location in the base sequence of a gene. The mutations that have been observed to produce beneficial effects are base substitution mutations to genes that are already expressed or changes in the genes that control the expression of functional genes. In differentiated multicellular organisms there must be sections of DNA separate from the protein code gene that control the expression of a protein in different groups of specialised cells and so for a novel gene coding for characteristics that did not previously exist to be produced as a result of random mutations both the novel base sequence of the new gene and the associated regulatory genes must be produced. In a complex multicellular species with a limited reproduction rate the number of separate mutations required to produce the required number of separate base changes in both the protein code and regulatory genes would be exceedingly high because the vast majority of mutations will be harmful. Natural selection can't sort the mutations before they produce an advantage and a selective advantage may require a number of separate mutations to occur before survival is increased. The view that evolution happened as a result of such unlikely combinations of mutations is not supported by numerical calculations so it is a guess, a complex multicellular species would be likely to be rendered extinct by the exceedingly high number of mutations required to produce the genes for a novel characteristic in a limited time frame. [22] Mutations are frequently observed in unicellular organisms such as bacteria and yeast, some of these mutations appear to produce beneficial effects. Is this similar to the evolution of multicellular organisms? [A] No. Beneficial mutations in bacteria and yeast are not appropriate models for speculation about beneficial mutations in multicellular organisms with specialised cells where genes that regulate expression in the appropriate cells are needed as well as genes that code for the proteins that produce the novel characteristics. Many separate fortunate and unlikely coincidences are required in a limited time to produce a new characteristic in a differentiated multicellular organism, and the observation of single fortunate coincidences in isolation is not evidence that this can happen. A base substitution mutation can be compared to a roll of a dice with millions of sides, in the case of the bacterium _E. coli_ the dice has 16.8 million sides since E. coli has 4.2 million Nitrogen bases in it's DNA and each base is one of 4 types. A single roll may cause a base substitution to an expressed gene in a bacterium that alters the surface coat protein and such a change may be beneficial for a bacterium. A few numbers could work. A novel characteristic in a multicellular organism such as the first appearance of bones around a dorsal nerve cord would require novel genes. In most cases a species will lack genes that can be duplicated and produce the useful code by substituting a single base so multiple rolls will be needed to make a cell protein code gene, other multiple rolls will be needed for a gene that regulates expression of the new protein code in the appropriate cells (how much protein is made) and still more multiple rolls will be needed for a gene that determines the cell types and locations where the gene is expressed. In mice and humans the mutation dice have 1.2 x 10^10 and 1.3 x 10^10 sides respectively, in each case this is four times the number of Nitrogen bases in the haploid genomes of these species. A significant proportion of the numbers will produce harmful effects and one such roll will render a series of rolls useless. Gene regulation can involve multiple regulatory genes at each stage and more than one gene will be needed. Unicellular organisms are not a model for vertebrate evolution. [23] Is it possible to definitively disprove evolution? [A] It may be possible to definitively disprove evolution (what everybody means by evolution, not the disingenuous definition) by calculating the probability of the combination of random mutations that would be needed for complex characteristics to evolve in differentiated multicellular organisms and comparing this with the total number of individuals in a vertebrate species that can reasonably be assumed to have lived over the length of geological time when significant change in the fossil record of vertebrates of this kind is observed. We may not know enough about the nature of genes to do this yet since one of the important factors in the development of novel complex characteristics is the control of the expression of particular genes in specialised cell types and the molecular nature of this control is not currently understood. It is reasonable to assume that the control of gene expression in specialised cells of multicellular organisms involves a significant number of bases in their DNA and at the current rate of increase of our knowledge of molecular biology this information is likely to become available in the next decade or so. When this is known a person who has a very good understanding of molecular and general biology and an aptitude for probability calculations should then be able to prove definitively that new kinds of life could not be produced by evolution. [24] Are there other flaws in the Neo-Darwinian explanation for the origin of all species as a result of random mutations and natural selection following the appearance of the first living organism? [A] Yes. Some characteristics in organisms are produced by several genes and in some cases these genes will not be useful in isolation. If a single new gene was produced by random mutations and the new gene is unused it will be likely to be damaged by mutations over successive generations and will only remain in a population for a limited time. For combinations of several genes to be produced by random mutations not one but many vastly unlikely events must occur in a limited number of individuals in a limited number of generations. This is so unlikely that it is effectively impossible, yet the evolution explanation requires this virtually impossible chance appearance of groups of complex genes to happen repeatedly during the development of complex species from simple ones. This flaw in the evolution explanation is most obvious in the very early stages of the development of life. The evolution of a complex processes like photosynthesis could not have occurred by random mutations and natural selection because these processes require combinations of genes to function and the presence of only one or two of these genes would not produce a selective advantage. Without a selective advantage a potentially useful base sequence would have little chance of surviving enough generations to accumulate the number of mutations required to form part of a functional group of genes. Only a relatively small number of biochemical processes would be present in a simple ancestral organism, photosynthesis requires a pigment to trap photons of light and use the energy from the photons to raise electrons to higher energy states as well as coenzymes to transfer the energy from electrons to enzymes. Many additional enzymes are needed to synthesise molecules that store energy, the pigment, the coenzymes and the enzymes that convert the energy captured by the pigment are complex molecules. The Calvin Cycle never contains molecules smaller than 3 Carbon atoms and it is far from certain that a functional biochemical pathway for photosynthesis involving 1 or 2 Carbon intermediates could exist since such a pathway would involve large energy jumps, possibly too large for the energy to be transferred by electrons associated with pigments. Without such a pathway photosynthesis could not have evolved. Even with such a pathway many genes are needed for photosynthesis and these genes would not be useful in isolation. Natural selection could not sort mutations to produce these genes until the process of photosynthesis had begun and so the evolution of photosynthesis would require many genes for enzymes to transfer energy and for the synthesis of a pigment to be formed purely by unsorted random mutations. Other examples of characteristics that require several genes include the biochemical processes that synthesise complex molecules. These reactions often occur in several stages, each stage of the reaction is carried out by a different enzyme and each enzyme is coded for by a different gene. For multiple step biochemical processes to have arisen during the early stages of cellular development by the natural selection of mutated genes each step would have to be useful in isolation because of the small number of enzyme genes that would have been in existence at this time. Genes coding for enzymes that produced steps that were not functional at a given stage of change would be likely to be damaged by mutations before the number of genes required to produce a novel multiple step process that rendered the genes useful could be produced by random mutations. [25] I have heard that some people claim evolution is now a fact. Is this true? [A] Only some supporters of evolution attempt to claim this. One way of pretending that evolution is a fact is to use the word fact in a way that is different from the meaning it has for most people, defining a fact as something that is probably true rather than something that is definitely true. Many people believe that evolution is almost definitely true however this is both a form of probably true and an opinion. When evolution is claimed to be a fact in this way without explaining that the word fact is used to mean something different to the usual meaning of something that is definitely true, the claim is misleading. Another way of pretending that evolution is a fact is to use a definition of evolution that includes very small changes in a population, then to say that small changes occur and so evolution is observed. This is also misleading because the term evolution has been commonly used for more than a century to mean the whole process of speciation as a result of natural processes following the formation of the first ancestral organism and this usage is still current. People who claim evolution is a fact without explaining that the word fact or the term evolution is used in a narrow sense that is different to the current and more common usage must know that their claim of evolution as a fact is likely to be misunderstood, thus the people who claim evolution is a fact either do not properly understand the subject or are being deliberately misleading and are therefore dishonest. [26] My science educator claims evolution is a fact and Iam concerned that he or she is misleading students. What can I do? [A] You could speak to this person and politely point out that the use of the word fact in this context is misleading and should be clarified since the word evolution in Biology refers both to the current definition of genetic change and to an unproved theory based on the one proposed by Charles Darwin and Alfred Wallace. If this does not help then it is likely that your educator either lacks understanding of the subject or is dishonest. You could then raise this issue with someone in the administration of the educational institution you belong to, some consider it good manners to move up one level of administration at a time if your complaint is not resolved at any given level. Many people who actually understand evolution recognise that it is an explanation that cannot be proved to be correct, although most biologists believe that evolution is what actually happened. Origins is an issue that many people are interested in and when evolution is popularised, the actual position "most scientists are convinced that ...." often becomes distorted by oversimplification to be "what actually happened was .." and the popularisation becomes a misleading representation of the true picture. This distortion is worsened by a team spirit feeling that produces a tendency to overstate the case of one side in a disagreement. [27] Since evolution is unproved, what are the alternatives? [A] Some people believe that the origin of living things is unknown and possibly unknowable, the only serious alternative to evolution is a belief that God created living things. There are different schools of thought among Christians who regard the bible as truth. Many biblical creationists believe that God created different kinds of living things but do not think that the time scale of the creation process is important. Young earth biblical creationists believe that God created life on earth 6,000 to 12,000 years ago. Some of these people believe that God created each species individually and others think that some separate species have arisen in this time by natural processes. Old earth biblical creationists believe that God created life on earth over the time scale estimated by geologists at around 4,500 million years, their views differ on the number of species God created directly and the amount of natural variation that produced species diversity. Some believe that all species were created separately by God and others, including this writer, believe that God created different kinds of living things then mutations and natural selection produced additional species within these kinds. Some Christians believe that God created the first living organism and that mutations and natural selection produced the present variety of species purely by natural processes without the active intervention of God. Some also believe that God set up the starting conditions for life so that it would inevitably appear. [28] What is the "fine tuning" argument? [A] Many biblical creationists believe that God created different kinds of living things with the potential for a limited amount of change by natural selection to enable adaptation to new or changing environments. It annoys them when others observe this fine tuning process in operation and claim that it is evidence for a completely different type of change, large scale change to produce very different kinds of living things. [29] Does the fossil record show that Darwin was right? [A] No. The fossil record does not show the gradual change from one kind of life to another that Darwin predicted but reveals long periods when relatively little change took place and episodes when large amounts of change took place in a short period of geological time. All the major animal phyla appeared in a rapid "explosion" of life forms at the beginning of the Cambrian period that is dated about 600 million years ago. [30] Many people think that the fossil record and the similarity of DNA from different groups of organisms indicates direct biological connections between species. Is this view consistent with creation? [A] Yes. God may have created different kinds of organisms by modifying existing species, deliberately altering the Nitrogen base sequence in the DNA of gametes or zygotes (such as unfertilised or fertilised ova) so that females produced offspring that were significantly different to themselves. God may also have ensured the survival of successive generations of individuals that were changed in this way. This progressive creation by modification explanation is a modern alternative to the older explanation of the individual creation of each species. Progressive creation by modification is consistent with evidence from DNA similarity studies. [31] Is progressive creation by modification a form of evolution? [A] No. The sculpting of one species into another at the molecular level would produce similar fossil and DNA evidence to the evolution explanation but progressive creation is not evolution. In the evolution explanation random mutations sorted by natural selection is the process that is thought to have produced new kinds of living things. In the progressive creation by modification explanation God deliberately produced new kinds of living things by the deliberate modification of the DNA in existing species. Random mutations sorted by natural selection is not the process that produced new kinds of living things according to this explanation and so progressive creation by modification is NOT a form of evolution. The term mutation is inappropriate to describe multiple changes in base sequence that arose directly from the active intervention of God. Researchers using recombinant DNA do not describe the alterations in base sequence they produce as mutations and creation events where God adds designed base sequences to an existing species to form a new kind are also different to mutations. [32] Is the progressive creation by modification explanation consistent with the available evidence? [A] The fossil record shows the appearance of increasingly complex kinds of living organisms over time and the remains of some species that may be intermediate stages between major groups. This is entirely consistent with the modification of existing species by the active intervention of God to produce specifically designed novel sequences of Nitrogen bases in the chromosomes of gametes or zygotes. These creation events could produce new kinds of living things with new characteristics when a number of new genes are formed in this way. Mutations and natural selection could then produce different species within these newly created kinds of organisms, explaining the great diversity of form we observe among living species and in the fossil record. Over geological time progressive creation by modification would produce increasingly complex kinds of living things together with a small number intermediate stages and this is what the fossil record shows. The similarity of base sequences in the DNA of extant (living) species is consistent with progressive creation by modification since only a small proportion of the bases in the chromosomes of existing species would need to be changed by God to produce each new kind of living organism. Since current species are, in this view, descended from ancestors that are common to other species then DNA similarity is expected. The biochemical similarity of extant species is consistent with progressive creation by modification over geological time. In this explanation the increase in complexity of organisms is produced by the deliberate modification of existing genes, the replacement of sections of DNA that do not code for protein with genes that code for new proteins or functional lengths of RNA or the addition of new genes. Kinds that are created modifications of existing species would retain the same basic biochemistry so different kinds of living organisms that are descended from a common ancestor as a result of creation by modification will have similar biochemistry. Homologous (related) structures present in fossil and extant species such as the pentadactyl (5 digit) limbs of vertebrates are consistent with creation by the modification of existing kinds of living things to produce new kinds with the same body plan since only a small proportion of the genes in an existing species would need to be changed to produce, for example, a kangaroo from a quadruped. [33] Is the similarity of vertebrate embryos evidence of evolution? [A] No. The similarity of the early embryos of different vertebrates is evidence for common descent but it does not indicate the process that produced the change, the similarity of embryos is entirely consistent with progressive creation by modification. [34] Is the presence of vestigial limbs evidence of evolution? [A] No. The presence of vestigial limbs in snakes is evidence that suggests an ancestor with limbs, and therefore common descent, however both progressive creation by modification and evolution are consistent with this. Once a species has reached a high degree of adaptation to an environment there is no particular reason for God to continue changing the species to remove vestigial limbs. [35] Are "transitional" fossils evidence of evolution? [A] Some fossils appear to be the remains of organisms with characteristics that are intermediate between those of major groups. Examples include _Archaeopteryx_, a bird that had a number of characteristics similar to those of reptiles, and Therapsida, an order of reptiles that had some characteristics similar to those of mammals. These examples are commonly quoted as representing transitional stages in the evolution of more advanced or complex groups, however they would also be animals that were well adapted to a particular environment before environmental change rendered them extinct. Transitional forms are consistent with progressive creation by modification since God was designing ecosystems as well as species and these extinct forms of life would have occupied ecological niches that were later filled by more advanced species. User Contributions: |
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