Origins TheologyForum for the discussion of Creation Science (Young/Old) vs Theistic Evolution. Discussion of Atheistic Evolution should be taken to the Discussion and Debate forums.
Since I first came to this forum, I found the topic of mutations in debate between the two factions. The statement made by many creationists is as the following (in many forms, paraphrases, and lengthy versions)*:
Macro-evolution can not occur because it requires mutations in order to occur. The chance of a beneficial mutation being present in a being is so small that it is virtually impossible for the creature to gain a useful mutation as opposed to a harmful mutation.
However, I have long pondered on the statement. However, I have come to the conclusion that such a proposition is irrelevant, for it leaves out the major component of evolution in the process of its deduction: Natural Selection.
As mutations provide diversity, the enviromental changes select which 'versions' of the creature, if you will, that obviously have the advantage in the situation. However, even if the mutation in question is a negative change, it could still prove to be useful in the context of the situation given.
For example, a variation may appear that would traditionally be harmful to the creature's ability to survive and reproduce. However, that does not apply since things... change
The constantly shifting enviromental changes could easily pick that trait for survival over others. Thus, over time, those who do not possess it are removed from the gene pool, inevitiably.
What I fail to understand about the creationist argument is that given the fact that mutations (good or bad), can or can not be good or bad given the situation given. Good and bad seem to be a marker that we (humans) assign on things, and in the theory of evolution by natural selection, it is not exactly so.
How can macro-evolution not occur therefore, if a harmful mutation can then prove to be good given the fact that the enviroment through natural selection selects the favorable trait in the community, and not vice versa?
Since I first came to this forum, I found the topic of mutations in debate between the two factions. The statement made by many creationists is as the following (in many forms, paraphrases, and lengthy versions)*:
Macro-evolution can not occur because it requires mutations in order to occur. The chance of a beneficial mutation being present in a being is so small that it is virtually impossible for the creature to gain a useful mutation as opposed to a harmful mutation.
However, I have long pondered on the statement. However, I have come to the conclusion that such a proposition is irrelevant, for it leaves out the major component of evolution in the process of its deduction: Natural Selection.
As mutations provide diversity, the enviromental changes select which 'versions' of the creature, if you will, that obviously have the advantage in the situation. However, even if the mutation in question is a negative change, it could still prove to be useful in the context of the situation given.
For example, a variation may appear that would traditionally be harmful to the creature's ability to survive and reproduce. However, that does not apply since things... change
The constantly shifting enviromental changes could easily pick that trait for survival over others. Thus, over time, those who do not possess it are removed from the gene pool, inevitiably.
What I fail to understand about the creationist argument is that given the fact that mutations (good or bad), can or can not be good or bad given the situation given. Good and bad seem to be a marker that we (humans) assign on things, and in the theory of evolution by natural selection, it is not exactly so.
How can macro-evolution not occur therefore, if a harmful mutation can then prove to be good given the fact that the enviroment through natural selection selects the favorable trait in the community, and not vice versa?
*No, this is not a strawman by any means.
Some good points. There are several fallacies in the creationist argument.
1. Yes, there is no absolute "good" or "bad" to apply to a variation (a better term than mutation).
2. It turns out that only about 2.6 per thousand mutations are directly harmful. That is, that they result in death or lowered fertility. Directly. This means that the number of absolutely directly harmful mutations is very low, not high. Also, the average mutation rate is at least one per individual. For humans, it looks like 4 per individual. So right now among the human population, there are 24 billion mutations. The odds that at least one of them will be beneficial in any particular environment approaches virtual certainty. See #4
3 997.4 mutations per thousand are either neutralin the environment, beneficial in the environment, or harmful in the environment. The key here being, of course, the environment. What is harmful in one environment is either neutral or beneficial in another.
4. Each individual represents one chance in the lottery. Natural selection doesn't care if 999 out of 1,000 individuals get "bad" mutations, because natural selection will preserve the "good" one. So it doesn't matter how "rare" the mutation is (which they are not anyway), because the odds are that one member of a population will be the lucky winner in the lottery. The odds of any particular individual winning is low, but the odds of someone winning are 1 -- certainty.
5. Neutral mutations are kept in the population generation to generation by means of Mendelian genetics. Thus, each population already has a huge amount of variation in the population that has accumulated generation by generation in case the environment changes. It is likely that the variation useful in the new environment is already present in a lucky individual in the population.
__________________ "If sound science appears to contradict the Bible, we may be sure that it is our interpretation of the Bible that is at fault." Christian Observer, 1832, pg. 437
"Christians should look on evolution simply as the method by which God works." Rev. James McCosh, theologian and President of Princeton, 1890
A large number of mutations that are not directly harmful to a population's survival rate, are harmful in some other way, and are passed down to the next generation. For example, in the human population, familial hypercholesterolemia, cancer (one of the most common results of genetic mutations) (for example, the APC gene is the cause of familial colonic polyps), Down's Syndrome, etc are examples of mutations that are harmful and in some cases lower a population's survival rate, even if they do not directly result in immediate death or lowered fertility. Now granted, there are examples like the mutation that causes sickle cell anemia, but also causes resistance to malaria, but those mutations in reality do much more harm than good, whatever the environment. Random mutations mix up, not create, genetic information, and they are usually harmful.
We continually find one after another harmful gene mutation damaging the human population, but only very occasionally is there an even somewhat beneficial one. There are currently over 4500 genetic diseases in the human population. It is also interesting to note that after extensive experiments with fruit flies and frogs, evolutionists have still found no or very few beneficial mutations.
Furthermore, the fact that many harmful mutations do not directly affect survival, means that those mutations will be passed on and proliferate, meaning that we would see a decrease in the overall health of the population's DNA, rather than an increase (not coincidentally, we see the former today). This is because they would not be adequately "selected out" by natural selection.
"Mutations, in time, occur incoherently. They are not complementary to one another, nor are they cumulative in successive generations toward a given direction. They modify what preexists, but they do so in disorder, no matter how…. As soon as some disorder, even slight, appears in an organized being, sickness, then death follow. There is no possible compromise between the phenomenon of life and anarchy." Pierre-Paul Grasse, Evolution of Living Organisms
"No matter how numerous they may be, mutations do not produce any kind of evolution." Pierre-Paul Grasse, Evolution of Living Organisms
"If any organ existed which could not have been formed by gradual modifications, my theory would break down." - Charles Darwin
A large number of mutations that are not directly harmful to a population's survival rate, are harmful in some other way, and are passed down to the next generation. For example, in the human population, familial hypercholesterolemia, cancer (one of the most common results of genetic mutations) (for example, the APC gene is the cause of familial colonic polyps),
In this case, the cancer does not show up until after the person has kids. Therefore it is invisible to natural selection. Yes, it lowers the lifespan of the individuals involved but, unless it lowers life expectancy into or below the child bearing years, it has no effect on the population's survival.
Down's Syndrome, etc are examples of mutations that are harmful and in some cases lower a population's survival rate, even if they do not directly result in immediate death or lowered fertility.
1. Down's syndrome are all primary mutations. They are not passed down because men with Down's syndrom are sterile in most cases. Also, without medical care, the person does not live long enough to have kids. So while tragic to the individual, the mutation is continually weeded from the population.
Now granted, there are examples like the mutation that causes sickle cell anemia, but also causes resistance to malaria, but those mutations in reality do much more harm than good, whatever the environment.
Sickle cell does a lot of good in the environment where malaria is endemic. Sickle cell is only harmful if you have both alleles as sickle cell. If you are heteozygotic -- one sickle cell and one normal -- you are resistant to malaria but no side effects.
So, what you tend to have is a population that is heterozygotic. When they mate you get 25% homozygotic non-sickle, 50% heterozygotic, and 25% homzygotic for sickle cell. The homozygotics are removed by the environment or the disease but 50% survive. That is doing good because, without the sickle cell allele, everyone would die of malaria.
Random mutations mix up, not create, genetic information, and they are usually harmful.
Again, the data says that only 2.6 per thousand mutations are actually harmful. We can go into how that data was gathered if you want.
Creation of information comes from selection, not the mutations themselves. Information is created whenever there is a selection among possibilities. That's elementary information theory. So, since each individual represents one possibility and more individuals are born than survive and reproduce, natural selection always increases information.
What some mutations do -- gene duplications and chromosome duplications -- is make more genetic material for information to be stored on.
We continually find one after another harmful gene mutation damaging the human population, but only very occasionally is there an even somewhat beneficial one. There are currently over 4500 genetic diseases in the human population. It is also interesting to note that after extensive experiments with fruit flies and frogs, evolutionists have still found no or very few beneficial mutations.
1. Genetic diseases are biased data, because we can see the sickness. Beneficial mutations can only be found by looking for positive selection. They are small. Here is a partial estimate of beneficial mutations in humans: 6. Pardis C. Sabeti, David E. Reich et. al. Detecting recent positive selection
in the human genome from haplotype structure. Nature 419 24 OCTOBER 2002. 7 Hollox EJ, Poulter M, Zvarik M, Ferak V, Krause A, Jenkins T, Saha N, Kozlov AI,
Swallow DM. Am J Hum Genet. 2001 Jan;68(1):160-172. Epub 2000 Nov 28. Lactase haplotype diversity in the Old World.
8. Gilad Y, Rosenberg S, Przeworski M, Lancet D, Skorecki K. Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):862-7. Evidence for positive selection and population structure at the human MAO-A gene.
2. The original fruit fly experiments were designed to test the hypothesis that mutations were heritable. Therefore they looked at multiple and macromutations. The flies and frogs were irradiated with a just-below-lethal dose of x-rays. That is because, in the 1930s, mutations could only be detected with the naked eye. So it meant a large change in appearance. So this meant many mutations per individual and large ones. These are going to be "harmful" because of that. But the experiments showed what they were designed to show -- mutations are heritable.
Furthermore, the fact that many harmful mutations do not directly affect survival, means that those mutations will be passed on and proliferate, meaning that we would see a decrease in the overall health of the population's DNA, rather than an increase (not coincidentally, we see the former today). This is because they would not be adequately "selected out" by natural selection.
If they do not affect survival, then they are not harmful. In humans, we have exempted ourselves from most of natural selection. So you are looking at a biased data set. In other species in the wild, I don't see this happening.
"Mutations, in time, occur incoherently. They are not complementary to one another, nor are they cumulative in successive generations toward a given direction. They modify what preexists, but they do so in disorder, no matter how…. As soon as some disorder, even slight, appears in an organized being, sickness, then death follow. There is no possible compromise between the phenomenon of life and anarchy." Pierre-Paul Grasse, Evolution of Living Organisms
Right. Mutations, by themselves are not coherent in time or cumulative toward a direction. They are random with respect to the needs of the individual or population. However, selection is coherent in time and cumulative. What Grasse sees as lacking in mutations is done in the second part of the process -- selection.
"No matter how numerous they may be, mutations do not produce any kind of evolution." Pierre-Paul Grasse, Evolution of Living Organisms
Not by themselves. You need variation and selection. BTW, what is your source of the quotes? You did not get them from the original book because you don't have page numbers or the year of publication. I sincerely doubt you have read the book yourself. You can prove me wrong, of course, by putting in the entire paragraph this sentence comes from. I hope you do show me to be wrong, because we have had really nasty experience of misquotes by creationists. It would be refreshing that that was not the case here.
"If any organ existed which could not have been formed by gradual modifications, my theory would break down." - Charles Darwin
__________________ "If sound science appears to contradict the Bible, we may be sure that it is our interpretation of the Bible that is at fault." Christian Observer, 1832, pg. 437
"Christians should look on evolution simply as the method by which God works." Rev. James McCosh, theologian and President of Princeton, 1890
Douglas Futuyma Evolutionary Biology, pages 384-385.
"If the heterozygote has higher fitness than either homzygote, both alleles are necessarily propagated in successive generations, in which, of course, union of gametes yields all three genotypes among the zygotes. Hterozygote advantage is also termed overdominance or heterosis for fitness. If the fitness of AA, AB, and BB are 1-s, 1, and 1-t respectively, selection wil bring the allele frequences from any initial value to the stable equilibrium p = t/(s+t, q = s/(s+t) where p and q are the equilibrium frequencies of A and B respectively. The equilibrium frequencies of the allesles and genotypes thus depend on the balance of fitness of the two homozygotes."
"Single locus heterozygote advantage has been documented in a few cases, including WAtt's study of PGI in Colias butterflies. The best known case is is the beta-hemoglobin locus in some African and Mediterranean human populations. One allele at the is locus, sickle-cell hemoglobin (S) ... The relative finesses have been estimated as W(aa) = 0.89, W(as) =1, W(ss) =0.2 [where aa is homozygote normal and as is heterozygote, and ss is homozygote sickle
cell]. The heterozygote advantage therefore arises from a balance of opposing selective factors: anemia and malaria. IN the absence of malaria, balancing selection yields to directional selection, because then the AA genotype has the highest fitness. In the African-American population, the frequency of S is about 0.05 and is declining due to mortality."
__________________ "If sound science appears to contradict the Bible, we may be sure that it is our interpretation of the Bible that is at fault." Christian Observer, 1832, pg. 437
"Christians should look on evolution simply as the method by which God works." Rev. James McCosh, theologian and President of Princeton, 1890
1. Yes, there is no absolute "good" or "bad" to apply to a variation (a better term than mutation).
2. It turns out that only about 2.6 per thousand mutations are directly harmful. That is, that they result in death or lowered fertility. Directly. This means that the number of absolutely directly harmful mutations is very low, not high. Also, the average mutation rate is at least one per individual. For humans, it looks like 4 per individual. So right now among the human population, there are 24 billion mutations. The odds that at least one of them will be beneficial in any particular environment approaches virtual certainty.
While both of these are probably true (I'm not sure about the data in point #2, but I don't doubt it) there are still major problems with turning to mutation/variation for the answer to evolution.
1. When mutations occur, information in a species DNA is either lost or copied incorrectly. A fly with an extra set of wings didn't get anything new because it already had the information needed for a pair of wings. This allows for a new species of fly to come about, but a fly could never evolve into a bird because it does not already have the information available that is necessary to have feathers or a beak. "Neither observation nor controlled experiment has shown natural selection manipulating mutations so as to produce a new gene, hormone, enzyme system or organ" (Michael Pitman 'Adam and Evolution' pp.67-68).
4. Each individual represents one chance in the lottery. Natural selection doesn't care if 999 out of 1,000 individuals get "bad" mutations, because natural selection will preserve the "good" one. So it doesn't matter how "rare" the mutation is (which they are not anyway), because the odds are that one member of a population will be the lucky winner in the lottery. The odds of any particular individual winning is low, but the odds of someone winning are 1 -- certainty.
2.As you said, there are many, many mutations among humans today, but at the same time none of us has evolved into any new kind of organism. For that to happen we would have to see mutation upon mutation upon mutation. It may be a certainty that one person will win the lottery, but what are the odds that the same person will win the lottery next month and the month after that and so on. This idea has been likened to taking a thousand turtles to a busy one thousand lane interstate highway and trying to get them to cross it. Odds are one of them will make it across the first lane before it gets killed in the second. However, the scientists conducting this experiment want to prove it's possible to accomplish, so instead of starting all over, they airlift another thousand turtles to the beginning of the second lane until one of them happens to make it across then repeat the process until all one thousand lanes have been crossed. They claim that it proves a turtle can cross a busy one thousand lane interstate highway but all they have really proven is that out of a thousand turtles one of them can make it across one lane of that highway.
Incorrect analogy, because evolution does not require many beneficial mutations to happen to one individual. What happens is that one individual out of many gets a beneficial mutation, avoids general bad luck, and survives long enough and mates often enough to have many offspring. Half of these have beneficial mutation and so servive and breed better then those that do not and eventually those with beneficial mutation come to dominate population. Then one individual out of many gets another beneficial mutation - etc.
A better analogy would be if there was a big traffic island between each lane. 2000 turtles try to cross the first, one pair survives. They settle on the island, breed, and after a while a population of 2000 turtles has grown up on the island. They then try to cross the next lane and a pair survive - etc. No need for airlifting, just plenty of sex
Incorrect analogy, because evolution does not require many beneficial mutations to happen to one individual.
Thanks for pointing that out. After rereading my post I can see that you're right. Somewhere along the line while I was typing that my thinking must have switched over from mutation to amino acids and proteins and cells forming or something along that line.
1. When mutations occur, information in a species DNA is either lost or copied incorrectly. A fly with an extra set of wings didn't get anything new because it already had the information needed for a pair of wings. This allows for a new species of fly to come about, but a fly could never evolve into a bird because it does not already have the information available that is necessary to have feathers or a beak. "Neither observation nor controlled experiment has shown natural selection manipulating mutations so as to produce a new gene, hormone, enzyme system or organ" (Michael Pitman 'Adam and Evolution' pp.67-68).
Again, this is the shell game. Remember, natural selection is a two-step process.
Pitman is correct but irrelevant. Natural selection does not "manipulate" mutations, but selects among them for those mutations that do produce a new hormone, enzyme system, or organ.
Now, some mutations make new DNA. That is, new genes. Copying errors include copying the gene twice instead of once -- gene duplication -- so that now you have two copies instead of one. Since you still have the original function in one copy, the second copy can now have mutations that give a new function. Whole chromosomes can be duplicated. Or you can copy part of the chromosome (a single strand of DNA) and then attach it to another chromosome. If you do this backwards, it is completely new DNA. This is called a transposition. There is also cases where DNA is inserted into a genome. This is done via transposons. Many of the growth factors in humans started out as viral genes that got inserted into our genome. This is new information to us.
A fly is an invertebrate. So it can't evolve into a bird anyway. However, a tetrapod (dinosaur) could. Sometimes when an allele is modified, you do get something new.
Also, in development, you often don't have to have a completely new gene to get a new feature. You simply have to change how long the gene is expressed. This happens in the transition from dinos to birds.
Science 1996 May 3;272(5262):738-41
Requirement for BMP signaling in interdigital apoptosis and scale formation.
Zou H, Niswander L
"Interdigital cell death leads to regression of soft tissue between embryonic digits in many vertebrates. Although the signals that regulate interdigital apoptosis are not known, BMPs--signaling molecules of the transforming growth factor-beta superfamily--are expressed interdigitally. A dominant negative type I BMP receptor (dnBMPR-IB) was used here to block BMP signaling. Expression of dnBMPR in chicken embryonic hind limbs greatly reduced interdigital apoptosis and resulted in webbed feet. In addition, scales were transformed into feathers. The similarity of the webbing to webbed duck feet led to studies that indicate that BMPs are not expressed in the duck interdigit. These results indicate BMP signaling actively mediates cell death in the embryonic limb."
Turn off BMP and you turn scales into feathers. No new gene.
2.As you said, there are many, many mutations among humans today, but at the same time none of us has evolved into any new kind of organism.
Uh, that's not entirely true. Andean and Himalayan highlanders have genetic adaptations for living at high altitudes. That's a new type of human. The !Kung are showing the beginning of reproductive isolation. They don't interbreed among the rest of the humans in Africa and they are adapted to living in the Kalahari desert.
For that to happen we would have to see mutation upon mutation upon mutation. It may be a certainty that one person will win the lottery, but what are the odds that the same person will win the lottery next month and the month after that and so on.
You forget selection. This is where population genetics comes in and where selection "fixes" alleles of genes. Fixation is where every member of the population has the allele. Alleles are different forms of the gene. A mutation makes a new allele. So, what you have is selection favoring one allele over all the others in the population. After several generations (depending on how severe the selection pressure is) every member of the population has the first mutation. So when the second one appears, it occurs in an individual with the first one. Cumulative selection cuts down those odds that worry you.
Humans are a poor example to use because we are not subject to most selection pressures because our technology alters our environment and, as a species, we are very young. So, what you see happening elsewhere in nature doesn't necessarily happen to us.
This idea has been likened to taking a thousand turtles to a busy one thousand lane interstate highway and trying to get them to cross it. Odds are one of them will make it across the first lane before it gets killed in the second. However, the scientists conducting this experiment want to prove it's possible to accomplish, so instead of starting all over, they airlift another thousand turtles to the beginning of the second lane until one of them happens to make it across then repeat the process until all one thousand lanes have been crossed. They claim that it proves a turtle can cross a busy one thousand lane interstate highway but all they have really proven is that out of a thousand turtles one of them can make it across one lane of that highway.
Your analogy is flawed. The odds are that more than one will get across the first lane. Then they breed and you now have a thousand to start across the second lane. Again, since it is only one lane being crossed, many will make it. Again they breed and you have a thousand to try getting across the third lane. Again, that is only one lane and many make it. And so on. The odds are that some will make it across all the lanes.
I have a better analogy for you. This is across generations of testing.
You have a 1 in 1024 chance of correctly winning 10 coin tosses in a row. But I can guarantee you I can find someone who can do so. How? Simple, use cumulative selection in the form of a single elimination tournament. I start with 1024 people and pair them up. Then each pair tosses a coin. The 512 winners are selected to go to the next round. Again they are paired and do a coin toss; the 256 winners are selected to go to the next round. Repeat this 7 more times. Now you have 2 people who have won 9 coin tosses in a row. The winner of this round has won 10 coin tosses in a row. And it is a certainty that such a person will be found with this method. We have taken odds of 1 in 1024 and converted that into virtual certainty. Now, I don't know which individual will win the tosses, but it is certain that one of them will, given the algorithm of the competition. Evolution by natural selection is a competition algorithm, more complex but analogous to the single elimination tournament algorithm.
You aren't using selection. You are simply having everyone in the generation survive and thus you have to have the second mutation land in one individual among millions. But you can't ever forget selection.
__________________ "If sound science appears to contradict the Bible, we may be sure that it is our interpretation of the Bible that is at fault." Christian Observer, 1832, pg. 437
"Christians should look on evolution simply as the method by which God works." Rev. James McCosh, theologian and President of Princeton, 1890
Your closing statement is a strange one though. "How can macro-evolution not occur therefore, if a harmful mutation can then prove to be good given the fact that the enviroment through natural selection selects the favorable trait in the community, and not vice versa?"
It does not automatically follow that because random (unpredictable to us) mutation and natural selection do in fact occur, therfore any kind of change is possible.
Just because random mutation and natural selection do occur does not mean that microbes turned into men.
The onus is on you to demonstrate this happened not on creationists to demonstrate it cannot happen.
But as naturalism precludes creation as a legitimate theory it has no choice but to hypothesise that it did happen
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