Problems for Evolution with Natural Selection and Sexual Reproduction

The next issue I want to address is the problem of the evolution of Sexual Reproduction. I want to preface this post by stating that the following statements and thought grew out of a conversation I had with an Atheist I met on Twitter who goes by the Twitter name @almightygod. He also happens to be a fellow blogger here on WordPress, and you can find him and his blog at http://almightygod.wordpress.com/ Anyways, these statements and thoughts I am about to share grew out of contemplation and reflection on topics discussed during an email correspondence I had with this man, and I don’t actually know if any of these are valid objections (let alone whether they have been brought up by others), nor do I know if these objections have already been presented and refuted, or if they are original to me, and I want you to get involved and let me know in the comments what you think of my arguments, if you have heard them before, and if you know of any refutations to the following arguments (or if you have refutations yourself). I am really hoping to generate a lot of conversation on this topic, and I encourage you to post any thoughts or problems you have with any of my arguments. Anyways, lets get on to the topic at hand, the problems I see with the evolution of sexual reproduction.

What exactly is Natural selection? It is not some force with a will that chooses, it is a name given to a concept of how individual members of a species gets their genes into the next generation. It is not something that acts on anything, it is an explanation. natural selection is simply the idea that those members of a species that get more of their genes into the gene pool have a greater chance for their genes to survive and carry over into the next generation. Natural selection does not do anything, and therefore it would have no effect on the mutations in any way and therefore cannot add anything to those mutations. Natural selection is simply the idea that mutation A is a useful mutation, and therefore would be more advantageous for species X to have. If enough individual members of species X that have mutation A reproduce and pass along mutation A, then mutation A will have a greater chance of surviving into subsequent generations, and therefore become a normal part of species X. There are a few problems with this though.

First, mutations are not a good explanation for new info, because a mutation is usually only a denaturing of a protein, and therefore it is not a prime candidate for being a means of introducing new, useful information. Second, let us examine a hypothetical situation to see another problem for natural selection that involves sexual reproduction.

Let us assume that Brian works at State Farm Insurance Company, typing up risk-assessment reports on a computer all day. Brian happens to have been born with a few mutations. Let us say that the first mutation Brian has is that he has developed Chameleon-like eyes, which can look and pivot independent from each other. The second mutation Brian has developed is that of an extra set of functional arms. So, imagine Brian, who has four arms and two eyes that can look and focus on two different things at the same time. This would be very advantageous for a person working at State Farm typing up reports all day to have, as he could type up these reports on two different computers at the same time.
The problem, however, is that for these advantageous mutations to be passed on and make their way into the gene pool of the next generation, Brian has to find someone to mate with. This would not be an easy task for someone with big obnoxious chameleon eyes and two extra arms. This person would be looked upon as a freak (regardless of whether this prejudicial view of Brian is right or wrong), and he would have a harder time reproducing. In addition, there is no guarantee that these mutations in the genes of Brian are actually going to be passed on to his or her offspring. They could be passive mutations, meaning that more dominate traits (normal eyes, and only having two arms) could be passes along instead, or they could simply not be passed along at all. The problem is that these mutations have to be passed on to the next generation, and there is no guarantee that a mutated member of a species is a desirable mating partner for other members of a species, let alone that these mutations will be passed along to subsequent generations.

The point of this hypothetical situation is to show that just because a mutation is beneficial does not guarantee that such a mutation will be passed along to the next generation. It is possible that advantageous mutations would make a member of a species undesirable as mating partners for other members of that species, and as such, not prime candidates for passing along the mutation.

Another problem for genetic mutations to become a source for change from one species to another is the fact that practically all mutations will cause either harmful effects or no effect at all. During the email correspondence Dave stated that, “[n]atural selection is the process that scoops up this advantage and passes it to the next generation, while letting the harmful mutations die out.”

I have a few problems with this. First, as previously stated, natural selection is not a person that can do something, so it cannot decide to scoop up an advantageous mutation and assure that it makes it to the next generation, while letting the harmful mutations die out. Why should we assume that natural selection will carry on the beneficial mutations, but leave the harmful ones out? Natural selection has been described as a blind process, and as a blind process, without a person or personality behind it, it cannot care whether a mutation is beneficial or harmful. If a creature with a mutation, whether that mutation is harmful or beneficial, survives long enough to reproduce, then it will pass those genes along to the next generation. If, as Dave admits, the majority of these mutations are harmful or have no effect, then it is much more likely that the mutations being passed along into the next generation are harmful to the creature rather than beneficial. It is quite possible that several harmful mutations (which are more likely than beneficial mutations) are not going to be so disadvantageous as to cause a creature to die out before it has the chance to reproduce.

Even if one assumes that natural selection is the idea that all beneficial mutations will make it to the next generation (which is definitely not guaranteed) and that all harmful mutations will kill a creature before it can reproduce and pass its genes along to the next generation (which is also not guaranteed), all we are left with is a better-adapted version of the same species. This process of weeding out the harmful genes and perpetuating the beneficial ones may be true (though there is reason to doubt this), but it still does not bring us to the development of a new species because of such mutations. All that has been shown is that natural selection can aid a species in adapting to its environment, which in turn aids its ability to survive (micro-evolution), but this in no way brings us to the conclusion that natural selection can change or alter one species and cause it to become another (macro-evolution).

There are other problems I see for natural selection involving sexual reproduction. I don’t understand how a species or organism that reproduces asexually evolved into a species that reproduces sexually. It seems like this would require at least three highly miraculous mutations to take place simultaneously. First, you must have a “male” mutation and a “female” mutation simultaneously generate. At the same time these two such mutated versions of a particular species must also be sexually compatible with one another and they must have the ability to reproduce sexually with each other (meaning they must both be fertile). These highly unlikely mutations do not even begin to mention the fact that there must be a mutation that allows for sexual reproduction in the first place, and why should one believe that reproducing sexually benefits a species genes more than to asexually reproduce? Asexual reproduction just seems like an easier way to reproduce and pass along your genes, since you don’t need a mate who is compatible and able to sexually reproduce. If as Richard Dawkins says in The Selfish Gene, “They [our genes] are in you and me; they created us, body and mind; and their preservation is the ultimate rational for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines”1 why would they desire to develop sexual reproduction in the first place? Why not simply continue to perpetuate yourself through asexual reproduction, rather than risk dying out due to lack of a suitable partner? I understand that sexual reproduction creates more variation, which in turn creates more mutation, and therefore more species, but why should genes care of such things, if they care or think at all? It seems to me that Richard is anthropomorphizing genes and ascribing them human attributes.

In addition, there is a problem with a non-sexual organism developing sexual reproduction capabilities. There are several organs necessary for sexual reproduction, and a simple mutation is not going to alter an organism in such a way that it develops all of these organs at once if mutation even has the ability to develop such organs (independently or otherwise) in the first place. If it does not gain all such organs at once, then the creature has mutated a useless organ that is not beneficial or functional in any way without the other sexual organs. As previously stated, you also need two organisms that simultaneously develop sexual organs that are not only functional, but they must also be compatible.

Yet another problem I have with the idea of macro-evolution is the idea of life coming into existence from non-life (an issue I deal with in detail in another post on my blog from October 2011 entitled Evolution and the Origin of Life). Even if you somehow can explain how everything in the universe came into being out of nothing without a creator, you still have the insanely difficult (if not completely impossible) task of showing how life can come from non-life without a creator. Many have undertaken the task of attempting to prove how this can be done, and every single one of them has failed so far.

These are just a few of the problems I have seen with the theory of Evolution, that is, at least the macro evolutionary aspects of it. Micro evolution is a proven fact, but macro evolution still has many many problems facing it. As always, please feel free to leave your comments, questions and objections below in the Comments section.
1. Dawkins, Richard. The Selfish Gene. (Oxford: Oxford University Press, 1989) 24.

Advertisements

Tags: , , , , , , , , , , , , ,

3 responses to “Problems for Evolution with Natural Selection and Sexual Reproduction”

  1. janeyqdoe says :

    You’ve certainly expressed your doubts well. Kudos fr not sounding like a parody of Ray Comfort and his banana. Anyhoo, to deal with the issues you raised:

    I think the problem with the idea of beneficial vs detrimental mutation is that it is too simplistic of a view. A mutation can add something to the code, just as it can be a denaturing. The key thing to remember with a mutation is that it changes the way a gene is expressed, so even if there is not an addition of genetic code, the expression can still represent a new feature (for want of a better word) in the organism.

    Your second point seems to deal primarily with the idea of the big mutation, or at least your example (which I must say I find quite creepy) does. Natural selection primarily deals with small variations that afford the organism a better chance of surviving to the age at which it can reproduce and thus pass on its genes. We’re talking what generally appears as natural variations within a population which work well as long as conditions stay the same. But when the plague strikes, those who have the variant gene that makes them resistant are going to live through it and pass on that gene. When humans began moving about the globe, our skin colour changed. Really dark skin is great at protecting you from skin cancer on the equator, but damned if those rickets don’t suck once you’re in Scandinavia.

    The idea that nature leaves behind the harmful is both true and false. You are correct in that natural selection makes no conscious selection. What you seemed to have missed, though, is that it really comes down to balance. If the positive mutations outweigh the negative, then they will survive, if it s the other way around, the positive mutations are wiped out with the negative ones. The human spine is a good example of that. It is quite vulnerable and not particularly good at holding up our weight when walking upright. However, becoming bipedal made us better hunters which made us better at getting enough food to last until sexual maturity. Natural selection does produce imperfections, because it is really a balancing act. I reckon that if a a god designed us, he did a pretty poor job and most likely got his design degree from a diploma mill.

    • Derek J. Brent says :

      First, I want to apologize for taking so long to respond. Last week was a long and rough one for me, because I was finishing up 34 pages of papers in the last week of school. Second, thank you Janey, for this articulated and amicable response.

      I have recently posted on another blog (one dedicated to the truth of evolution) and made a few comments on the metaphysical aspects (talking about presuppositions and faith) of an atheistic position with regards to the origins of evolution and the origin of life, and I have had to deal with many hostile, and condescending responses, most of which do not address the issues I raised, and instead simply attacked my intelligence, character, or other beliefs I held, without really addressing my comment. so again, thank you for coming here and contributing to the discussion in a friendly manner.

      On your first point, I can agree that beneficial vs. detrimental is a simplistic way of viewing it.

      “A mutation can add something to the code, just as it can be a denaturing.”

      Which occurs more often? I was taught that more often than not, it is a denaturing of the genetic code, rarely adding new information. I also understand what you are saying when you state “even if there is not an addition of genetic code, the expression can still represent a new feature” and agree that the denaturing of a protein can lead to the gene being expressed in a new way, and therefore it represents a different function for that protein; the point I want to stress is that the denaturing of the code, if it is to cause a new function, must necessarily denature the protein from one expression into another comprehensible expression. If the denaturing leaves a protein sequence that is unintelligible, then it will be neither a detrimental or beneficial mutation, but rather, a useless one.

      On your point about my mutations being too large of a change, and to quote you at length:

      “Natural selection primarily deals with small variations that afford the organism a better chance of surviving to the age at which it can reproduce and thus pass on its genes. We’re talking what generally appears as natural variations within a population which work well as long as conditions stay the same. But when the plague strikes, those who have the variant gene that makes them resistant are going to live through it and pass on that gene.”

      What you are talking about here is what I understand to be micro-evolution. I grant micro-evolution as true and proven. It is the idea that species adapt over time to their environment, and when a disastrous event occurs, those of a species that are adapted to better withstand or be resistant to that disaster, they survive while those not able to resist the disaster perish, leaving more of a species to reproduce that has this beneficial adaptation, and eventually it becomes a natural part of a species in that particular environment, though not necessarily in all other areas.

      What I do not grant as proven or true, is macro-evolution, or the idea that these small changes given enough time will cause enough variation to go from a species to a completely different species. what I have a problem understanding is how you can get from one species, say a squirrel, and make the leap to another species, say the brown bear through gradual, small changes in a species. For the record, I have no idea whatsoever if there is even a belief or theory that squirrels did or even could have evolved into brown bears, I am simply using them as an example. All the evidence in favor of evolution that I am aware of shows an evolution within a species to better adapt it to its environment, such as disease resistance, and not to irrevocably alter it into another species altogether.

      I can understand how micro evolution can explain why there are dark-skinned people, and light skinned people, based on the environment they found their population surviving in, but what I cannot understand, is how we are supposed to have evolved from a more primitive ancestor, the evolutionary ancestor we share with today’s primates, such as the chimpanzees. If we evolved from the same ancestor species, and we have evolved conscious thought, self-awareness, cognitive reasoning, and all the other aspects that come with having a “mind” why have there not evolved animals of other species with these cognitive faculties? What is it that prevented other species from developing a “mind” in the sense that we have a “mind” if having a mind is such a beneficial adaptation? How do you even get to a mind in the first place through natural evolutionary processes? It is quite a leap to go from the animal that is nearest to us intellectually (which, as far as I understand, are dolphins) and get to the mental capacity and ability of human beings. It is an advantage to have the mental ability and capacity that we have, and I don’t see why other animals wouldn’t have evolved them as well, given naturalism. Sure, there could be reasons why we are the only species to have evolved the ability to have a “mind,” but that is not my point, I am not saying they should or could, I am merely saying that it is interesting that there is such a large gap between us and every other animal. Heck, the mind isn’t even fully explainable given naturalism anyways, so why should we expect that it is the product of natural evolutionary processes given enough time?

      You say I missed that it comes down to balance, and that if there are more positive mutations than negative ones, the positive ones will survive, and if the negative ones outweigh the positive, both will perish.

      First, why does it matter whether there are more positive or negative mutations at a given time? It is not as if there is a scale, and every positive mutation balances a negative one, and that they cancel each other out. There can be a mixture of positive and negative mutations in a given community of a particular species, and I don’t think it is a numbers game in the sense that if there are more positive or beneficial mutations than there are negative ones that these positive ones will survive for sure. If there are positive mutations, that benefit a species, then it makes sense that they are perpetuated, and if a given mutation is not beneficial, that it is less likely to aid in survival and therefore more likely to be killed off, but it is not always the case that the beneficial mutation will make it into the next generation, and it is not always the case that the detrimental or negative mutations don’t get passed along. Sometimes the beneficial mutations will not make it to the next generation, while detrimental ones will. This is sheer luck, and it had to have happened for life, let alone the universe, to have happened naturally, so why should we think that mutations would be any different? This is why I don’t think it is simply a matter of balance, and there must be other mitigating factors that must also come into effect, and which I feel are not simply given occurrences.

      Second, even if we grant your premise here, I disagree that there has been enough positive mutations to outweigh the negative ones. It has been stated that over 70% of the mutations that occur are harmful, and the majority of the remaining 30% being either neutral mutations that caused no alteration, or weakly beneficial.¹ These mutations on their own would not be enough to evolve a species into another species. An.other website made the following statement:

      “The prestigious Journal of Theoretical Biology published a paper some time back analyzing the the minimum number of steps needed to evolve one species into another. Making all the most generous assumptions in favor of the Theory of Evolution, and using standard statistical methods, the probability was so low that speciation could not be expected to occur even once over billions of years.”²

      On the human spine as “poor design”, I am not sure I would grant you that it does a poor job at holding up our weight when walking upright. A poor job here would be if say, the majority of fit human being having back problems, due to the strain our body weight has on our spines, and that is not the case. One website stated that “The most unique difference about us, though, is our ability to carry our skull with the greatest of ease balanced atop an almost perfectly upright structure.” and goes on to say that “It is because of this uniqueness in design to accommodate upright posture that we have paid a price.”³ It may be that our spines are not able to support overweight people, and I would say that this is because it was not designed to hold the amount of weight we are forcing our spines to hold. Even when it comes to cars (which are designed), sometimes you must sacrifice certain features in favor of others such as sacrificing safety or carrying capacity features for other features, such as MPG or speed, though these facts wouldn’t mean the car wasn’t designed, it would simply means we can’t expect that something have everything we desire that it should have.

      All together, there are still plenty of things I see wrong with a naturalistic macro evolutionary process as an explanation for the origin of species. If (macro) evolution is true, it would require intervention from God to have occurred the way modern science claims that it does, and even then, I don’t think there is good reason to think (macro) evolution is true. There is plenty of evidence for micro-evolution, but too often it gets jumbled with the claims of macro evolution and passed off as proven, and I simply do not think this is the case.

      ¹see sources like http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1871816/?tool=pmcentrez

      ² http://www.chabadworld.net/page.asp?pageID=%7BA0732C60-01A6-4690-A570-F3C4332D6069%7D

      ³ http://www.upright-health.com/spine.htm

      • Shane McKee (@shanemuk) says :

        Hi David,
        I’ve been perusing a few other posts on your blog, and couldn’t let this one pass. You’re really *very* confused about the role of mutation in evolution, but don’t panic – you are not alone. These are common misconceptions. Firstly, microevolution is the same process as macroevolution. There is no fundamental distinction at the mechanism level. What you see as “macro” is simply “micro” that has gone on for longer, and where different populations have diverged from each other. Sure, there are issues here (Brian Switek makes the point fairly well) from a paleontological viewpoint, but this doesn’t change the fact that natural selection is the process by which gene frequencies shift within populations, and that is the driving process of evolution itself.

        Mutations occur all the time. You have about 100 mutations in your DNA that were not present in either of your parents – this is the case for each generation. Many of those mutations are probably selectively neutral, but some will be responsible for aspects of your phenotype, and that exposes them to selection. Populations therefore *must* accumulate loads of mutations over time. Many of these (even if they might be thought to be “beneficial”) are lost; others bumble along at a low level, only to be lost later, or to perhaps rise to prominence in a selective sweep.

        But mutations certainly do introduce new information into a genepool – *any* change is technically new information, and natural selection can be viewed as a sculpting process, *removing* much of that new information, but keeping that which results in better reproduction.

        And that is critical – “beneficial” in evolution only *ever* means that it enhances its own representation in the next generation of the gene pool. And this is where Dawkins got it absolutely right. Selection does not occur strictly at the level of the individual, the family unit or the species – it occurs at the level of the gene in the genepool, with the proviso that genes are bundled together in communities that we may call organisms.

        The evolution of sexual reproduction is a complex topic, and has been discussed at length in many papers and popular books. Suffice it to say that it is not the problem you think it is 🙂

        Hope that helps!
        -S

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: