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Tuesday, July 22, 2014

A Real-Life Example of “Convergent Evolution”

Posted by jlwile on July 25, 2012

Several times in the past (here, here, here, here, and here), I have written about convergent evolution and the problems it poses for anyone who wants to believe that all the amazing organisms we see today are the result of a mindless evolutionary process. As a quick review, remember that in general, evolutionists claim that similarities are the result of common ancestry. All vertebrate limbs look very similar, for example, because all vertebrates evolved from a common ancestor. While evolution “tweaked” the design of each animal’s limb so that it could be properly adapted to its environment, the basic structure of the vertebrate limb is the same in all vertebrates because they all inherited that basic structure from a common ancestor.

Of course, as is usually the case for evolution, more and more data have been collected that are inconsistent with this idea. Dolphins and bats, for example, both use sonar to navigate and to seek out prey. However, there is no hypothetical sonar-using common ancestor that links them. Thus, while they are very similar in this regard, evolutionists have to say that this particular similarity is not due to common ancestry. Instead, it is the result of “convergent evolution.” Both animals evolved the ability to use sonar independently, along different evolutionary lines. In other words, evolution “converged” on the same system in two different, unrelated cases.

Now please understand that this similarity is very deep. Indeed, the genes that allow this process to happen are nearly identical in these two animals.1-2 So in order to understand the use of sonar in dolphins and bats, evolutionists have to believe that evolution just happened to come up with the same system (all the way down to the genes) for navigation and predation in two completely different lineages.

If this were the only case in which unrelated organisms have amazingly similar systems, it might be reasonable to chalk it up to evolution just being “lucky” enough to come up with the same system twice. However, as evolutionist Dr. Simon Conway Morris tells us, nature abounds with examples of this. Indeed, most evolutionists believe that eyes must have evolved independently in unrelated lineages as many as 60 times in order to be consistent with the data at hand!3

If all of that seems far fetched to you, don’t worry. You are not alone. Most reasonable people can see when an attempt to explain around inconvenient data becomes desperate.

Now, of course, the creationist and the intelligent design advocate have no problem with the fact that there are so many similarities among organisms that could not possibly be the result of common ancestry. Indeed, any view that recognizes the world and the life within it are products of design would expect such things. After all, what do we know about competent designers? They tend to take a design that works, and they use it over and over again in lots of unrelated projects. After all, why “reinvent the wheel” every time you are designing a new machine?

That brings me to the video that is at the top of this post. It shows an artificially-engineered jellyfish that is really quite remarkable. The team that created it started by studying the cellular architecture of a real jellyfish. Then, they formed a silcon-based polymer into the shape of a flat flower with eight petals. Finally, in an attempt to mimic what they found in the jellyfish, they grew a single layer of rat heart muscle on the polymer in roughly the same way that a real jellyfish’s muscle is organized. When an electric field is applied across the polymer (or even in the water), the rat muscle contracts, and the flower-shaped polymer crunches down on itself, just like the body of a jellyfish does. When the electric field is removed, the muscle relaxes, and the polymer relaxes as well, just like the body of a jellyfish does!4 In the end, this artificial jellyfish “swims” much like a real jellyfish does.

This is a marvelous feat of engineering, and the entire team should be congratulated for their results. At the same time, however, you have to admit that what they have constructed is rather crude when compared to the real thing:

Also, while the paper didn’t go into details regarding exactly how much energy it took in order to make the artificial jellyfish swim, I suspect that a real jellyfish uses significantly less energy to swim significantly more elegantly! Thus, while this is truly a marvel of engineering, it doesn’t come close to what you see in the real world. No one is willing to argue that this crude version of a jellyfish is the result of a mindless evolutionary process, but there are many who want to convince you that the significantly more efficient and elegant real jellyfish is!

But I digress. My real point here is to emphasize how the designers of this artificial jellyfish put their creation together. They used muscle from a completely different animal – a rat. From a genetic standpoint, then, the muscles of a rat and this jellyfish are nearly identical. Obviously, this jellyfish doesn’t share a common ancestor with rats, so what do we have here? We have a real-life example of “convergent evolution” – two “organisms” with amazing similarity that cannot be explained by common ancestry. At the same time, however, the similarity is not explained by evolution independently coming up with the same solution in two separate lineages. Instead, the similarity is the result of design. Specifically, it is the result of a designer taking a working system from one organism and using it to build another “organism.”

I think that most examples of “convergent evolution” in nature can be explained in the same way!

REFERENCES

1. Yiang Liu et al., “Convergent sequence evolution between echolocating bats and dolphins,” Current Biology 20:R53 – 4, 2010
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2. Ying Li et al., “The hearing gene Prestin unites echolocating bats and whales,” Current Biology 20:R55 – 6, 2010
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3. Richard Dawkins and Yan Wong, The Ancestor’s Tale: A Pilgrimage to the Dawn of Evolution, Mariner Books, 2005, p. 588
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4. Janna C Nawroth et al., “A tissue-engineered jellyfish with biomimetic propulsion, Nature Biotechnology, doi:10.1038/nbt.2269, 2012
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Comments

12 Responses to “A Real-Life Example of “Convergent Evolution””
  1. gracekalman says:

    I recently scared a wannabe athiest with this information…he was shocked that a seemingly intelligent person wouldn’t believe evolution. After all, “all the evidence proves it.” To which I replied, “What evidence?” Structural homology was all he could come up with. Poor kid.

  2. jlwile says:

    Grace, that is unfortunately very common among evolutionists. They claim that “all the evidence points to it,” but if they can cite any actual evidence, it usually doesn’t point to evolution!

  3. Jason says:

    Can it also be said that this created experiment is not a creature, nor is it a life form or alive?

    It looks to me like some kind of hybrid contraption using both synthetic and biological components to “simulate” life.

  4. jlwile says:

    Jason, this created contraption is definitely not a living organism. It has muscle, which is composed of living cells, but those muscle cells will not last long, as they don’t have the support tissues they need for all the processes of life. That’s why I put “organisms” in quotes. The created contraption is not an organism. However, it is an analog of one.

  5. Anthony says:

    Dr Jay,
    A simple thank you. I stumbled across your site and have enjoyed going through it. You present with integrity, a touch of humour and at a level easily digestible to the casual reader. Keep up the good work.

  6. Jason says:

    Thank you for the clarification Dr Wile.

  7. jlwile says:

    Thanks so much, Anthony!

  8. jlwile says:

    My pleasure, Jason.

  9. Elizabeth says:

    Did they move from the “evolutionary tree” model to the “evolutionary bush” in an attempt to explain homology of organisms in different Phyla? for example: human eye and squid eye

  10. jlwile says:

    Not really, Elizabeth. The “bush” model came about when it became clear that there just aren’t many (if any) transitional forms in the fossil record. At that point, they said that evolution is like a bush. What we see now are the leaves, and the inner branches, which describe the actual path of evolution, are not visible. This is either because of the incompleteness of the fossil record or because of the short timespan over which the transitional forms lived.

    The human eye and squid eye are supposedly another example of “convergent evolution,” where evolution just happened to come up with the same solution in unrelated organisms.

  11. zuma says:

    Is it true that radioactive method has been used by scientist to assess the age of fossils?
    How reliably would the radioactive method be in assessing age of fossils?
    The actual date of fossils might well be a few thousand years ago and yet the unreliability of the method used in assessing the actual date of fossils might well mislead people to believe it should be a billion years ago.

  12. jlwile says:

    Zuma, radioactive dating methods are rarely used directly on fossils. Carbon-14 dating is the main one that can be used directly on fossils, and it has a theoretical limit of 100,000 years, with a practical limit that is even younger than that. When radioactive dating methods are used, they are generally used for rocks. One of the more popular methods,for example, is the potassium-argon method, and it is used on igneous rock, which is the kind of rock that forms from lava solidifying.

    The problem with radioactive dating methods is that they are notoriously unreliable. For example, radiometric dates often conflict with the generally-accepted date for a geological formation (see here and here). In addition, when we know for certain the age of a rock, radioactive dating doesn’t give the proper answer (see here and here). Also, different radioactive dating methods often give different dates for the same geological formation.

    I think the big problem with radioactive dating is the assumption that radioactive half-lives have been the same throughout earth’s history. When I got my PhD in nuclear chemistry, I thought that was a reasonable assumption. However, the data have drug me (kicking and screaming) to conclude that it probably isn’t a good assumption.

    So in the end, I think radioactive dating is unreliable. As a result, I don’t consider it a good method of determining the age of anything.

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