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Monday, October 20, 2014

Sex Really Complicates Things!

Posted by jlwile on October 14, 2010

Drosophila melanogaster (Image by http://commons.wikimedia.org/wiki/User:Aka)

Evolutionists have always looked at nature in an overly simplistic way. They are forced to do so by their preconceived notions. As I mentioned previously, evolutionists cannot begin to appreciate the complex nature of genetics. If they did, they would understand that mutations cannot possibly add information to the genome and, as a result, they would understand that evolution has strict limits. It can only “tinker” with the genetic information that already exists in a population in order to produce individuals that are more fit to survive certain conditions. We call that “microevolution.” It cannot produce fundamentally new and innovative biological structures, which is what is necessary for macroevolution to occur. Thus, while microevolution (which has been demonstrated in both nature and the lab) is consistent with what we know about genetics, macroevolution (which has never been demonstrated in nature or the lab) is not consistent with what we know about genetics.


Of course, evolutionists won’t give up their overly simplistic view of nature, because it is necessary in order for them to cling to their dogma. As a result, they make many predictions, which time and time again are falsified by the data. Not surprisingly, a detailed study of microevolution in the fruit fly known as Drosophila melanogaster has falsified yet another one of their predictions.

For you to understand the prediction and how it was falsified, you need a bit of background, which starts with bacteria. Bacteria are ideal organisms to study when it comes to microevolution, because they reproduce rapidly, it is very easy to keep and store large populations, and their genomes are simple compared to those of most other organisms. As a result, a lot of detailed studies have been done attempting to understand how microevolution occurs in bacteria. Typically, a population of bacteria is subjected to some kind of environmental stress, and over time, their genomes are tracked to see what happens. One very ambitious version of this kind of study has been going on for more than 40,000 generations now, and not surprisingly, only microevolution has happened. Nothing even approaching macroevolution has occurred.

When you look at the details of these studies, however, some fascinating genetics are revealed. For example, when a bacterium develops a mutation that is clearly advantageous for its conditions, that mutation not only survives in future generations, but it quickly becomes the norm in the population. This makes perfect sense, since the bacteria with the advantage will propagate better than those without the advantage, so after many generations have passed, the population will consist mostly of those that have the advantage. In genetic terms, we say that the mutation becomes “fixed” in the population. Since this process is seen over and over again in such experiments, evolutionists have developed a term for it. They call it a “mutational sweep.”

So when bacterial microevolution is studied, it is characterized by mutational sweeps.1 A mutation that makes a bacterium more fit to survive will be quickly fixed, sweeping through the population until, after several generations, nearly every bacterium has that mutation.

Now here’s where the overly simplistic thinking of evolutionists comes into play. Evolutionists have assumed that when animals microevolve, the same thing happens. If a mutation occurs that is clearly advantageous for an animal, it will quickly sweep through the population so that, after several generations, nearly all individuals in the population will have that mutation. Why is this overly simplistic thinking? Because bacteria reproduce asexually, while most animals reproduce sexually. Sexual reproduction is quite a bit more complex than asexual reproduction (hence the title of this piece). Thus, to assume that microevolution occurs the same way in organisms that reproduce sexually and asexually is ridiculous. Nevertheless, that has been the reigning view in evolution…until now.

The September 30 issue of the journal Nature has a paper that reports on the results of an experiment in which researchers followed the microevolution of Drosophila melanogaster for 600 generations.2 Each generation, the researchers selected those that had the fastest development from egg to adult and allowed them to breed and produce the next generation. Over the 600 generations of the study, this process produced flies that developed roughly 20% faster than the flies that started the experiment.

So clearly some microevolution had occurred. That’s not surprising. Using artificial selection over the course of 600 generations is bound to have an effect. What’s interesting, however, is that since the genome of Drosophila melanogaster has been fully sequenced, the researchers could compare the genomes of the evolved fruit flies to those of the fruit flies that began the experiment.

Now if the overly simplistic view of evolutionists had been correct, the results should have been straightforward – whatever genetic changes that produced quickly-developing fruit flies should be fixed throughout the population. Not surprisingly, that’s not what the researchers found. As the authors state:

Notably, we observe no location in the genome where heterozygosity is reduced to anywhere near zero, and this lack of evidence for a classic sweep is a feature of the data regardless of window size.

What the researchers conclude from these data is quite reasonable, and it does not bode well for those who are forced to believe in macroevolution.

We conclude that, at least for life history characters such as development time, unconditionally advantageous alleles rarely arise, are associated with small net fitness gains or cannot fix because selection coefficients change over time.

So the researchers offer three choices, none of which look good from a macroevolutionary standpoint:

1. There are few mutations that are wholly advantageous.

2. What wholly advantageous mutations that might exist produce very little advantage.

3. What wholly advantageous mutations that might exist cannot get fixed in the population, because the conditions change too quickly for any mutation to be wholly advantageous for very long.

Remember, if evolution occurs easily in any organisms, it does so in bacteria. Bacteria have short generations and large populations, so they can sample all kinds of mutations. Comparatively, animals have long generations and small populations. As a result, the number of mutations they can sample throughout the course of history is significantly smaller. Thus, if macroevolution is to occur in animals, the process of mutations being naturally selected must be more efficient than it is in bacteria. That doesn’t seem to be the case. Instead, observations of microevolution in animals indicate that sexual reproduction causes all sorts of complications that seem to reduce the efficiency of the selection process.

This is not surprising at all to anyone who has a realistic view of nature, but it comes as a big surprise to most evolutionists.

REFERENCES

1. L Notley-McRobb and T Ferenci, “Experimental analysis of molecular events during mutational periodic selections in bacterial evolution,” Genetics 156:1493 – 1501, 2000. (Available online)
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2. Molly K. Burke, et al., “Genome-wide analysis of a long-term evolution experiment with Drosophila,” Nature 467:587–590, 2010. (Available online with subscription)
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Comments

8 Responses to “Sex Really Complicates Things!”
  1. Josiah says:

    That argument is complicated somewhat by the (non-permanent) sexual version of micro-evolution, wherein traits tend to develop from the concentration of genes already existent in the genome into single individuals, and thereafter into populations. The text-book example of finches wouldn’t need a host of mutations to adapt their beaks to the local island.

  2. jlwile says:

    Good point, Josiah!

  3. WebMonk says:

    “Evolutionists have always looked at nature in an overly simplistic way. They are forced to do so by their preconceived notions. As I mentioned previously, evolutionists cannot begin to appreciate the complex nature of genetics.”

    I dare you to send that to Dr. Todd Wood. I won’t bother giving you the fisking that insanely stupid statement deserves. If he feels like it, Dr. Wood can do that.

  4. jlwile says:

    Wow, WebMonk, the rationality of your argument is overwhelming!

  5. WebMonk says:

    No, I’m not making an argument. Merely alerting you that you just made one of the stupider statements I’ve heard recently. It was worthy of “Dr. Dino” Hovind.

    If you can’t realize why that is such a monumentally moronic position and want the explanation, head over to Dr. Wood, and if he has the time and inclination he can enlighten you.

    I could probably give it a pretty good go, but time would probably be saved if you heard it straight from a top-notch YEC biologist.

  6. jlwile says:

    WebMonk, of course you weren’t making an argument, because you can’t make a good one. As a result, you simply try to insult me in an attempt to bully me into accepting your position. It’s truly sad, but not incredibly surprising, given some of the other comments you have made.

    Dr. Wood is, indeed, a top-notch YEC biologist. He is also very busy (like me), and I obviously respect his time more than you do. Besides, I am not swayed by the argument from authority. If Dr. Wood also thinks it is a stupid statement, he is certainly entitled to that opinion. However, the statement can be backed up with quite a bit of evidence, including the evidence given in this post. The opinion of a top-notch YEC biologist is nice, but I will go with the evidence over such an opinion every time.

  7. WebMonk says:

    So, the fact that evolutionary biologists have made 99.99999999999999% of the advances in genetics is somehow meshed with “evolutionists cannot begin to appreciate the complex nature of genetics”??? And, the reason I suggested Dr. Wood in particular is that he has had more than a few things to say about “Junk DNA”, and your post about junk DNA on which you based your claim in this post is plain false in several areas.

    In theory, you’ve done some looking into the subject, but if you can still make claims like you’ve been doing, apparently you are purposefully blinding yourself. There’s nothing someone you don’t know (me or someone on your blog) will be able to show you that will somehow break through – “The dwarves are for the dwarves,” and all that.

    But, I was sort of hoping that someone you do “know”, like Dr. Wood, might have a chance of breaking through whatever it is that makes you think your above statements and claims are sensible.

    That’s why I’m not bothering to post any arguments here. It’s a waste of time. But what might not be a waste of time, is getting you to learn something from someone who has at least a minute chance of removing your blinders.

  8. jlwile says:

    Webmonk, you need to think a bit more clearly on this subject. Of course evolutionary biologists have made the most advances in understanding genetics. They are the majority of biologists, and they clearly get the vast majority of the research funds. Thus, even though their simplistic view of nature hinders their understanding of DNA (as I have made very clear on this blog), it is not surprising that most advances come from them.

    Actually, based on your comments on this blog, you are the one who is purposefully blinding yourself. I don’t know if the argument from authority or the argument from majority (or both) are so important to you that you refuse to look at the evidence, or whether there is something else that keeps you from looking at it. However, until you do look at the evidence, I am afraid that your comments will never be taken seriously by most of the readers of this blog.

    I am very open to whatever people I know or don’t know have to say. However, if they want to convince me, they will have to use evidence, which is something that is particularly lacking in most of your comments.

    I do find it interesting that for someone who is worried about wasting his time, you spend a lot of time posting rants that do nothing but attempt to insult me. You should realize that such rants are the ultimate waste of time, because they do nothing to advance your case.

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