Tag Archives: Darwinism

Three logical prerequisites for biological evolution to work

Hummingbird in flight
Hummingbird in flight

Biologist, blogger and super-mom Lindsay has written a post that explains what supporters of Darwinian mechanisms have to prove in order to explain the origin and diversity of life.

Here are the three things that Darwinists must demonstrate:

  1. It is possible to add biological information.
  2. There are more upward steps than downward steps (or at least a way to get more upward steps than downward steps at least some of the time).
  3. There does exist a gradual genetic pathway that can be climbed in tiny, incremental steps.

So first of all, the main two arguments for intelligent design and against naturalism are the origin of life and the Cambrian explosion. Both involve massive infusions of new biological information. So Lindsay is right to focus on whether Darwinism can add new biological information. But I wanted to focus on number three, because I really think that her post is about the burden of proof on Darwinists more than it is about our burden of proof. And we do need to get used to asking Darwinists for the evidence for their view.

Take a look at the detail on number three:

In order for evolution to be true, not only does information have to be added over time, but each successive change must occur in a living organism and it must be conserved by being passed on to offspring. Thus, the change cannot kill the organism or seriously disable it, or the change will not be passed on. This must be the case for EVERY step in the entire evolutionary sequence, no matter how small. At every step you must have a functional organism. Thus, the changes must be gradual enough that the tiny upward steps (if they exist) can achieve each new level without killing or disabling the organism. To use a simplistic analogy, if one tries to change from one word to another by changing one letter at a time (cat to cot to dot to dog, for example), there must, at every step, be an actual word that can be reached by changing one letter. In the Mount Improbable analogy, this means that there can be no upward jumps in the trail. If the maximum possible upward step is 6 inches, then there can be no 6 foot cliffs along the trail, or even 7 inch steps. If ever there is a step which requires more information than unguided evolution can provide, then evolution is falsified in that instance. It cannot account for the change in information if that is the case.

Now I have never seen a gradual genetic pathway from one body plan (phyla) to another body plan (phyla) in any peer-reviewed paper. What I need to see to believe in the ability of Darwinian mechanisms to drive change from one body plan to another is that sequence of changes at the genetic level. And I don’t just need to see the steps, I need to see the probabilities of getting the correct sequence of changes at the genetic level within the time available by chance. That’s what Darwinists assert in their theory – that’s what they need to prove. Talking about how one creature looks like another creature is irrelevant. My car looks like my Dads car, because we drive the same model, but different model years – and both cars are designed.

When people ask our side for evidence for our claims, we are able to produce the evidence to substantiate our claims, e.g. – cosmic fine-tuning factors or protein sequencing probabilities. I would like to see the other side do the same, and not just tell me a story. When I question people in the arts who accept Darwinism, they seem to be terribly disinterested in the details, and just want to jump to the conclusion shared by the smart people without thinking hard about all the steps in between. That’s intellectually lazy. The same thing happens with global warming with the non-scientists – they are more concerned about jumping to the “smart people” position, so you think that they’re smart. They aren’t really interested in hearing both sides, or looking at the evidence. I think people need to take it slow and look at the evidence, instead of deciding what to believe based on how other people perceive them. No need to rush to agreement to build up your self-esteem without doing the hard work first.

If you are looking to understand what the other side has to prove, and in a concise way, read her post.

New study: rising oxygen levels rejected as explanation of Cambrian explosion

Apologetics and the progress of science
Apologetics and the progress of science

So, just to refresh everyone, the Cambrian explosion was an event that occurred about 543 million years ago. In a very short period of time, less than 10 million years, probably 3-5 million, all of the major animal body plans emerged.

Here’s what the Cambrian explosion looks like:

Cambrian Explosion
Cambrian Explosion

The Darwinian theory says that there should be precursors to all of the new phyla that appear. But we have never been able to find any precursors. We’ve been looking in the fossil record for the slow transition from simple life to complex life that Darwin predicted, but we’ve never been able to find anything that explains the sudden emergence of the body plans in the Cambrian explosion.

There is no known naturalistic explanation for the rapid emergence of these “phyla”. But, naturalists were holding out hope that maybe a sudden rise in the level of oxygen might have “triggered” the required increase in complexity.

This is from Science Daily.

Excerpt:

Oxygen is crucial for the existence of animals on Earth. But, an increase in oxygen did not apparently lead to the rise of the first animals. New research shows that 1.4 billion years ago there was enough oxygen for animals — and yet over 800 million years went by before the first animals appeared on Earth.

Animals evolved by about 600 million years ago, which was late in Earth’s history. The late evolution of animals, and the fact that oxygen is central for animal respiration, has led to the widely promoted idea that animal evolution corresponded with a late a rise in atmospheric oxygen concentrations.

“But sufficient oxygen in itself does not seem to be enough for animals to rise. This is indicated by our studies,” say postdoc Emma Hammarlund and Professor Don Canfield, Nordic Center for Earth Evolution, University of Southern Denmark.

[…]The new study is published in the journal Proceedings of National Academy of Sciences.

[…]The results differ from other studies and raise several questions, such as: Why then did animals rise so late in Earth’s history?

“The sudden diversification of animals probably was a result of many factors. Maybe the oxygen rise had less to do with the animal revolution than we previously assumed,” says Hammarlund.

Now look here. I don’t see how a rise in oxygen level can create new body plans. Body plans are written in sequences of symbols – in proteins and DNA. I can no more believe that a rise in oxygen levels could create new animal body plans than I could believe that raising the level of oxygen in a computer lab could explain the new code that is being written by the software engineers. Body plans are information, and new body plans require new information. Information comes from software engineers – intelligent agents – not from rising oxygen levels.

In any case, the hypothesis was falsified. It isn’t the first time a naturalistic hypothesis for the Cambrian explosion was shot down (see below) and it won’t be the last.

Related posts

Is Darwinist P.Z. Myers right to say that the appendix is vestigial?

Apologetics and the progress of science
Apologetics and the progress of science

First, let’s hear prominent atheist P. Z. Myers, who believes in Darwinism, explain why he thinks that the appendix is a useless vestigial organ leftover from an unguided, random process of evolution:

The appendix in humans, for instance, is a vestigial organ, despite all the insistence by creationists and less-informed scientists that finding expanded local elements of the immune system means it isn’t. An organ is vestigial if it is reduced in size or utility compared to homologous organs in other animals, and another piece of evidence is if it exhibits a wide range of variation that suggests that those differences have no selective component. That you can artificially reduce the size of an appendix by literally cutting it out, with no effect on the individual (other than that they survive a potentially acute and dangerous inflammation) tells us that these are vestigial.

Got that? You can cut out the appendix and it has “no effect on the individual”.

Now let’s look at the peer-reviewed science, so we can get the truth of the matter.

My good friend Joe Coder told me about this article from the Melbourne Herald Sun.

Excerpt:

MELBOURNE scientists have discovered new proof that the appendix — the often-removed organ once thought to be redundant — can be crucial to digestive health.

Researchers from the Walter and Eliza Hall Institute have shown how a group of immune cells team up with the appendix to protect the gut during infection.

They work together during bouts of food poisoning and other bacterial illnesses, and also help boost the immune systems of cancer patients.

Lead researcher Professor Gabrielle Belz, a laboratory head from WEHI’s molecular immunology division, said about 70,000 Australians have their appendix removed every year — making it one of the most common surgical procedures.

“Popular belief tells us the appendix is a liability,” Prof Belz said.

“However, we may wish to rethink whether the appendix is irrelevant for our health.”

Prof Belz said surgeons no longer removed the appendix “at the first drop of a hat”, reserving surgery for more serious cases of appendicitis.

The new research, led by Prof Belz and leading French immunologist Prof Eric Vivier, has shown that innate lymphoid cells (ILCs) shield the appendix from harmful bacteria.

This allows the small organ to act as a safe haven for “good” bacteria, which could then “reseed” the intestines and restore the health of the digestive system.

Prof Belz, whose research was published today in Nature Immunology journal, said ILCs offered an added layer of immune protection for healthy people.

But they were vital in fighting bacterial infections in people with compromised immune systems, such as cancer patients, Prof Belz said.

“This is particularly important because ILCs are able to survive in the gut even during (cancer) treatments, which typically wipe out other immune cells,” she said.

Prof Belz said that ability of ILCs to withstand chemotherapy also opened up “new avenues of investigation” for cancer treatment.

This expands on a previous study reported by the Washington Post.

Excerpt:

The appendix “acts as a good safe house for bacteria,” said Duke surgery professor Bill Parker, a study co-author. Its location — just below the normal one-way flow of food and germs in the large intestine in a sort of gut cul-de-sac — helps support the theory, he said. Also, the worm-shaped organ outgrowth acts like a bacteria factory, cultivating the good germs, Parker said. That use is not needed in a modern industrialized society, Parker said. If a person’s gut flora dies, it can usually be repopulated easily with germs they pick up from other people, he said. But before dense populations in modern times and during epidemics of cholera that affected a whole region, it wasn’t as easy to grow back that bacteria and the appendix came in handy.

Evolution News comments:

[…][A] few months back David Klinghoffer reported that researchers in the journal Clinical Gastroenterology and Hepatology found:

Individuals without an appendix were four times more likely to have a recurrence of Clostridium difficile, [a pathogen common in hospitals,] exactly as Parker’s hypothesis predicted. Recurrence in individuals with their appendix intact occurred in 11% of cases. Recurrence in individuals without their appendix occurred in 48% of cases.

In other words, the appendix performs important immune-related functions. Thus, the appendix is not there to occasionally explode. With the appendix increasingly considered to be an important organ that you wouldn’t want to lose, researchers have also found that antibiotics can cure many cases of appendicitis (see Eriksson et al., 2006  ).

Look, everyone has to decide whether they want to believe in religion or whether they want to believe in science. I understand that some people want to assume a religion of naturalism, and then try to fit reality into that pre-supposed dogma. But I don’t think that’s the right way to develop an accurate view of reality. We should follow the scientific evidence wherever it leads, and we should seek the truth – no holds barred.

Positive arguments for Christian theism

 

Greg Koukl debates Michael Shermer on God, atheism, meaning and morality

The full transcript of a debate between Michael Shermer, editor of Skeptic magazine, and Greg Koukl, president of Stand to Reason. This debate occurred on Hugh Hewitt’s radio show, and was moderated by Hugh Hewitt.

HH = Hugh Hewitt
GK = Greg Koukl
MS = Michael Shermer

Here is a 32-page PDF with the full debate transcript.

And here’s an excerpt:

GK: Right. Actually, the big question here, Hugh, is whether it’s possible to be good without God. Now I’m not talking about whether it’s possible to be good without a belief in God. I certainly think that’s possible, but be good without God. And the answer to that question hinges entirely on precisely what you mean by good. And so I was going to give an illustration. So a man drags a young girl into the alley, he sexually abuses her, strangles here, and tosses her into the dustbin. Is that act wrong? Now I think everybody listening is going to admit it is wrong. But here is the real question. What do we mean when we say that that act of rape and abuse and murder is wrong? Are we describing the action itself, the object? Are we saying that the object, the rape, the murder, has a quality of being wrong, and therefore, wherever that rape goes, the wrongness follows it, just like your height, 6’ 2”, or whatever it is, is an objective quality of you. Wherever you go, your height follows you in the same way. Does the wrongness follow the rape? Well, if it’s a quality of the rape, if it’s an objective quality of the rape, then it does. And it doesn’t matter what people think about it, or what cultures decides, or what your evolutionary conditioning is. The rape is still wrong. The other alternative is that you’re not talking about the rape. You’re talking about yourself. You’re talking about your genetic conditioning. You’re talking about your culture’s decision about that kind of thing. And if that’s the case, then the truth of the wrongness of the rape is simply in the individual or the subject. And this is why philosophers distinguish between ethical objectivism and ethical subjectivism. Now there’s lots of different subjectivisms in ethics. But simply put, if you’re an ethical subjectivist, you’re a relativist. And actual ethics don’t exist. Ethics are an illusion. If you conclude that ethics are an illusion, there’s lots of different ways to explain it. Michael’s written a really great book, I think, called The Science Of Good And Evil. I’ve read most of it, and it’s well written, and it’s very compelling. But it’s a description about how the illusion of ethics has taken place. If you want to go that route, you’re welcome to go that route. But what you can’t do is you can’t then talk about morality as if it’s objective when your explanations are subjective. So this is a problem that I think all atheists, including Michael, have to solve. Are ethics objective or relative? And if they’re relative, then how can we make moral judgments that are meaningful on other people?

HH: Michael Shermer?

MS: Wow, let’s just get right into it. Well, I don’t think it’s quite so black and white. That is to say I think there are provisional moral truths that exist whether there’s a God or not. In other words, it’s wrong, morally, absolutely morally wrong to rape and murder. And that would be true whether there was a God or not. In other words, if…is God saying that it’s wrong because it’s really wrong, and He’s instructing us in his Holy Scripture that it’s wrong? Or is it only wrong because He said so? And if it turned out there wasn’t a God, would that make it okay? And my answer is no, it really is wrong, whether God says it’s wrong or not. That is to say I think it really exists, a real, moral standard like that. Why? Well, because first, you could ask the person who is being affected, we should always ask the moral recipient of the act, how do you feel about being raped or murdered or stolen from or lied to. And the moral actor will tell you, it doesn’t matter whether, if I could use a current example, I haven’t any idea if Tiger Woods and his wife are religious or not. But you can just ask his wife whether it was morally right or wrong, and she’ll tell you. It doesn’t matter whether there’s a God or not. It’s wrong. And so that’s the first principle. Just ask. Ask the moral recipient of whether it’s right or wrong. But I think Greg’s after something deeper, that is to say is there something even deeper still behind the moral actor’s feelings about how they’re treated. And the answer is yes, I think so. We’re a social species. We don’t live in isolation. We live as members of a group. And as such, there’s no possible way our group could survive, be cohesive, be a unit of any kind of solidarity against other groups, or against a harsh environment. If there were too much violations of social norms, that is if there were constant lying and cheating and raping and murdering, there’s no way a social group could hang together. And as such, as we all know, we’re very tribal. We’re tribal against other groups, but within our groups, we’re very pro-social, altruistic, cooperative. We have a good and evil in our nature. So to this extent, I find myself interesting often in agreement with my conservative friends on most of the things they consider morally, moral truths. That is, we share the same moral values, even though I come at it from a different perspective.

HH: Greg?

GK: Yeah, I’m actually not after something deeper here, Michael. At least to start out the discussion, I’m trying to be as simple and clear and precise as possible, because it’s very easy to weave together a bunch of things that sound persuasive, but turn out to be different things. Like for example, Darwinian evolution, which is a materialistic process, and here I mean the blind watchmaker thesis, the neo-Darwinian synthesis, natural selection working on mutations, and a kind of a cultural evolution that Michael has just referred to as we work together as a group to survive as a group. Those are two entirely different things. One is materialistic, Darwinian, the other one is intelligent design, quite frankly, where the group gets together and makes some determinations to encourage some behavior and discourage others. What I’m trying to do is to be able to answer the question that came up initially, is God necessary for morality, which Michael denies. It’s to say well, what is it that morality, that we’re trying to describe? It is either objective, and therefore an immaterial obligation that applies to certain behaviors, or it is subjective. The things that Michael described were variously subjective, evolutionary elements, subjective cultural elements, but then he affirmed that we all have good and evil in our nature, or an awareness of that. I agree with that entirely. We all are aware of those things. That’s why even if we don’t believe in God, we can still know morality and follow it. The question is what accounts for real, genuine objective morality?

HH: One minute to the break, Michael Shermer.

MS: I’m not arguing for cultural evolution. I’m actually arguing as part of our, what you described as materialistic, natural selection, Darwinian evolution, that it’s not enough to just pretend or fake being a good group member. You actually have to believe it, feel it, and live it. So what I’m arguing is that natural selected certain moral sentiments, as Adam Smith called them, moral feelings, an actual empathy, Adam Smith talked about, we actually empathize with somebody else, we can put ourselves into their shoes and feel their pain, I’m arguing that’s very real. It’s every bit as real a part of our evolutionary heritage as our eyes and our hands.

– – – –

HH: Michael Shermer, when we went to break, you were saying that evolutionary biology has produced a real morality.

MS: Yeah, I think really, Adam Smith had it right in his very first book, The Theory Of Moral Sentiments, long before Darwin, that we actually have in our biological nature, our human nature, the capacity to feel other people’s pain. He called it empathy, we think of it often either as empathy or sympathy. That is, we really do connect to other people. A lot of good research on this now, brain scans, you can show somebody a little video of somebody they know, or have feelings for, getting pricked with a pin, and the same areas of their brain light up, the pain receptors, as in the person getting the pin prick. In other words, we have an evolved tendency to really be deeply, emotionally connected to our fellow group members. And that’s why I say groups like World Vision, where you want to adopt a child, it doesn’t help to show a picture of 10,000 starving African kids. What does affect us is one child, a picture of one child with a little biography. That’s how you get people to adopt a child to donate. The reason for that is because essentially they’re tricking the brain, our brains into making that stranger an honorary family member, an honorary within group member, which is why I argue that free trade is one of the best ways of defusing normal tribal tensions between people. It makes them honorary friends, honorary members. Well, what’s going on there is we’re tricking the brain into sort of this evolutionary rule of thumb – be nice to people that are like you and that are related to you, and that you know, and that are fellow group members, and don’t do what our natural tendency is, is to be tribal and xenophobic against those other guys. And free trade is one of the best things you can do for that. So I’m arguing that’s actually tapping something deep within us.

HH: Greg Koukl?

GK: Yeah, basically, I agree with Mike completely here. We do have this tendency, and it seems to be universal among humankind. The question is, what is that tendency, actually? And what is the best way to explain it? And I see like a handful of significant problems with using evolution to explain morality. The first one is that evolution is a materialistic process. And here, I’m going back to an original point, and I don’t want people to lose it. There is no way that you can take molecules, and reorganize them in any fashion, over any length of time, and have pop out of the mixture an objective moral principle that’s immaterial, and that applies to human beings. All you’re going to get is a reorganization of the molecules. And what they can produce, and this is what Mike has done in his book, and he mentioned just s few moments ago, they can produce sentiments. They can produce feelings. They can produce behavior. But this leads us to the second problem of using evolution to explain morality, is that morality is more than sentiments, feelings and behavior. Morality entails things like motive and intention. I mean, you could have a guy walk into a garage, walk out with a hose, and is that wrong? Well, it depends. Is it his hose or somebody else’s hose? Did he intend to take the other person’s hose? Is he borrowing the hose? So we can see here are elements that are part of the moral thing that needs to be explained, that are immaterial, and therefore the Darwinian explanation can’t even in principle go there. It can’t do that job. But here’s the worst problem. Regardless of what our sentiments happen to be regarding moral actions, we can feel good or feel bad or whatever, the problem is that morality is prescriptive, not merely descriptive. That is it tells us not just what we did, but what we ought to have done in the past, and what we ought to do in the future. That is not something that any Darwinian mechanism can describe, because nothing about my biology can inveigh upon me to act a certain way for moral reasons in the future. It doesn’t tell me why I should be good tomorrow. This is a huge difference between these two views, the descriptive and the prescriptive. Prescriptive is part of morality, and can’t even, in principle, be explained by an evolutionary materialistic system.

HH: Michael Shermer, I’ll give you a start on that. We have about 45 seconds to the break, so you may want to…we’ll come back after the break and pick up. But what’s your start to that?

MS: Well, the start would be that again, let’s not think of evolution just as nature red and tooth and claw, and it’s nasty, brutish and short, but that in fact, we have this whole other social evolution. And I’m not talking about cultural evolution where we consciously make decisions, but subconsciously, because it’s in part of our nature to actually, seriously, deeply feel for other people and their actions, and the consequences of our actions, so that we actually have a sense of right and wrong that we’re born with, but then culture taps into and tweaks, one way or the other.

– – – –

HH: Michael Shermer, when we went to break, Greg had made the argument that the Darwinian model simply cannot explain immaterial concepts like morality, that there’s just no way you can rearrange the molecules to get there. You’re saying well, yes you can.

MS: Yeah, I think so, because if we think of morality as another suite of emotions that are involved with other people’s behaviors, the consequences of our actions, how we feel about them, how people feel about us when we do these things, that’s as every bit as important a biological part of our nature as anything else we talk about. So let’s take a real simple emotion. When you’re hungry, nobody does any calculations about the caloric input/output ratios of eating an apple versus an ice cream, although now it’s posted on the walls for us to see. But we just feel hungry, and we feel hungry for certain kinds of foods. The feeling of hunger is a proxy for something else. Evolution’s done the calculating for us. You need food, so we’re going to, your hypothalamus is going to secrete these certain chemicals that causes your stomach to rumble and so on. When you’re attracted to somebody else, a member of the opposite sex, nobody does the calculation by, let’s say, a man finds a woman attractive who has a .67 hip to waist ratio, and an hourglass figure, although that is pretty much universal. Nobody walks about with calipers taking measurements of who they’re going to want to date or ask out. You just look around, and you just go wow, I really find this woman attractive. It’s a feeling you have, okay? So those are kind of simple emotions, but sliding up the scale, the moral emotions are really no different. When I lie to somebody, I’ve violated a social norm, and they respond in a very angry, hostile way. So those emotions that we both share, guilt, shame, anger, disgust, involved a social relationship that whether it was a norm violation, those are the kinds of emotions that are just like hunger and sexual attraction that are built into us by nature, by evolution. Or, if you wish, this is how God created the moral sentiments, just like He created everything else in the universe, through a process of nature. I think that’s equally reasonable to argue. So I don’t see that it has to be an atheistic viewpoint versus a theistic viewpoint to get to our moral sentiments. Why couldn’t God have used evolution to create the moral sentiments as I’ve described them?

GK: Yeah, well, you don’t actually believe that, I know, Mike, so this is kind of like adding God to the soup, you know, if it makes people feel better. But the basic argument is that evolution all by itself can do the trick. And I think if your listeners are listening carefully, what they’re going to hear is Mike has just described, and if I’m being unfair to your assessment here, let me know, Mike, that moral feelings are simply that. They are sophisticated emotions that do some work for us for survival, and even on a group level. Now there’s a name for this. It’s called emotivism. A.J. Ayer, the famous atheist, offered this description of morality. It’s a relativistic scheme of morality. Morality doesn’t actually exist, Ayer argued. There is no objective right or wrong. Rape isn’t wrong itself. What happens is, we have feelings about it, and we express it in moral language, but rape isn’t really wrong. So your listeners are going to have to ask themselves the questions. When they just survey their own moral senses, and we all have access to this, do we want to believe that scientists have figured out that really what we’re doing is feeling sophisticated, complicated emotions, and that the emotions are in us, and we are not seeing anything about the action? Or does it seem like rape is wrong? Look, when I say rape is wrong, I’m talking about the rape. When I say liver is awful, I’m talking about me. I’m talking about my own tastes and preferences. It’s interesting, as Michael has given his explanation, though, that he’s doing, and I don’t know if you are aware of this, Michael, but you’re doing the very thing that I kind of warned against. You give a description of the foundations of morality that turn out to be relativistic, but then there’s a smuggling of a more objectivistic morality in the back door, like when Michael says you don’t have to do what your nature tells you to do, in other words, what you’ve been programmed by evolution to do. You can kind of rise above that. Well, now we’re talking about a morality that isn’t dictated by evolution, but a morality that we can employ through our acts of will, to rise above this kind of brutish evolutionary morality. And that sounds suspiciously like the very thing that I’m talking about here.

MS: But I don’t mean, there’s nothing to rise above by itself. Yes, we have to say rise above our tribal instincts to be xenophobic when we meet somebody who’s a stranger, who’s different from us. We all struggle against that, particularly in a black and white America, where there’s always been this underlying tension. Indeed, so culture helps us do that – education, travel, diversity of exposure to different people. That makes you a little more tolerant. Okay, but I’m not talking about that. What I’m talking about is tapping into the good part of our nature, the fact that in addition to that xenophobic tribalism we have, we also have this other side that almost never gets discussed in evolutionary…even in evolutionary circles, you’ll still hear evolutionary biologists talking about, in a way that Huxley did, and Herbert Spencer did in Darwin’s own time, that we have to somehow struggle mightily against our genes to overcome that nasty tendency we have to want to rape, kill, pillage and destroy. Well no, actually, we have this whole other side that’s just as genetically programmed into our nature. And the point of culture – education, politics, economics and so on, is to tap into the better angels of our nature as Lincoln said.

GK: Okay, here’s the question I have for you, Michael, then. You’ve identified that really, we have good and we have bad. That’s part of, under your terms, that’s part of our genetic nature, and we can choose to tap into what you call the good side. Why ever should we do such a thing if there is not a higher standard that directs our action to the better side, your words, than the bad side, your words, if really, ultimately, they are both the result of a genetic evolution, and from outside terms, neither is better than the other. Why should we do that, Michael?

MS: Yeah, well I don’t see how entering God into the equation changes that problem at all.

GK: Well, that’s the next step. What I’m trying to show is that the should comes from the outside, and if we can demonstrate that, then we can ask…

Read the rest by click here to get the PDF.

Convergence detected in the genetic structure of bats and dolphins

Apologetics and the progress of science
Apologetics and the progress of science

We have to start this post with the definition of convergence in biology.

In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

It is the opposite of divergent evolution, where related species evolve different traits.

On a molecular level, this can happen due to random mutation unrelated to adaptive changes; see long branch attraction. In cultural evolution, convergent evolution is the development of similar cultural adaptations to similar environmental conditions by different peoples with different ancestral cultures. An example of convergent evolution is the similar nature of the flight/wings of insects, birds, pterosaurs, and bats.

All four serve the same function and are similar in structure, but each evolved independently.

Jonathan Wells explains the problem that convergence poses for naturalistic evolution:

Human designers reuse designs that work well. Life forms also reuse certain structures (the camera eye, for example, appears in humans and octopuses). How well does this evidence support Darwinian evolution? Does it support intelligent design more strongly?

Evolutionary biologists attribute similar biological structures to either common descent or convergence. Structures are said to result from convergence if they evolved independently from distinct lines of organisms. Darwinian explanations of convergence strain credulity because they must account for how trial-and-error tinkering (natural selection acting on random variations) could produce strikingly similar structures in widely different organisms and environments. It’s one thing for evolution to explain similarity by common descent—the same structure is then just carried along in different lineages. It’s another to explain it as the result of blind tinkering that happened to hit on the same structure multiple times. Design proponents attribute such similar structures to common design (just as an engineer may use the same parts in different machines). If human designers frequently reuse successful designs, the designer of nature can surely do the same.

I’m a software engineer, and we re-use components all the time for different programs that have no “common ancestor”. E.g. – I can develop my String function library and use it in my web application and my Eclipse IDE plug-in, and those two Java programs have nothing in common. So you find the same bits in two different programs because I am the developer of both programs. But the two programs don’t extend from a common program that was used for some other purpose – they have no “common ancestor” program.

Now with that in mind, take a look at this recent article from Science Daily, which Mysterious Micah sent me.

Excerpt:

The evolution of similar traits in different species, a process known as convergent evolution, is widespread not only at the physical level, but also at the genetic level, according to new research led by scientists at Queen Mary University of London and published in Nature this week.

The scientists investigated the genomic basis for echolocation, one of the most well-known examples of convergent evolution to examine the frequency of the process at a genomic level.

Echolocation is a complex physical trait that involves the production, reception and auditory processing of ultrasonic pulses for detecting unseen obstacles or tracking down prey, and has evolved separately in different groups of bats and cetaceans (including dolphins).

The scientists carried out one of the largest genome-wide surveys of its type to discover the extent to which convergent evolution of a physical feature involves the same genes.

They compared genomic sequences of 22 mammals, including the genomes of bats and dolphins, which independently evolved echolocation, and found genetic signatures consistent with convergence in nearly 200 different genomic regions concentrated in several ‘hearing genes’.

[…]Consistent with an involvement in echolocation, signs of convergence among bats and the bottlenose dolphin were seen in many genes previously implicated in hearing or deafness.

“We had expected to find identical changes in maybe a dozen or so genes but to see nearly 200 is incredible,” explains Dr Joe Parker, from Queen Mary’s School of Biological and Chemical Sciences and first author on the paper.

“We know natural selection is a potent driver of gene sequence evolution, but identifying so many examples where it produces nearly identical results in the genetic sequences of totally unrelated animals is astonishing.”

Nature is the most prestigious peer-reviewed science journal. This is solid material.

There is an earlier article from 2010 in New Scientist that talked about one of the previous genes that matched for hearing capability.

Excerpt:

Bats and dolphins trod an identical genetic path to evolve a vital component of the complex sonar systems they use to pursue and catch prey.

The finding is unusual, because although many creatures have independently evolved characteristics such as eyes, tusks or wings, they usually took diverse genetic routes to get there.

Analysis of a specific gene has now demonstrated that although bats live in air and dolphins in water, where sound travels five times faster, they independently evolved a near-identical gene that allows them to accept high-frequency sound in the ear – vital for sonar.

The gene makes prestin, a protein in hair cells of the cochlea, which is the organ in the inner ear where sonar signals are accepted and amplified. Prestin changes shape when exposed to high-frequency sound, and this in turn deforms the fine hair cells, setting off an electrical impulse to the brain. So the protein has the important jobs of detecting and selecting high-frequency sounds for amplification.

When researchers examined the molecular structure of the prestin gene from a range of animals, they found that the variants in echolocating bats and dolphins were virtually indistinguishable.

Indistinguishable genes in animals that don’t share a common ancestor? Maybe a better explanation for the evidence we have is – common designer.