Evolutionary Complexity: The Development of Elaborate Structures Without Darwinian Selection



Nice little piece at Scientific American about the evolution of odd-ball structures like the human eyeball:

Charles Darwin was not yet 30 when he got the basic idea for the theory of evolution. But it wasn’t until he turned 50 that he presented his argument to the world. He spent those two decades methodically compiling evidence for his theory and coming up with responses to every skeptical counterargument he could think of. And the counterargument he anticipated most of all was that the gradual evolutionary process he envisioned could not produce certain complex structures.

Consider the human eye. It is made up of many parts—a retina, a lens, muscles, jelly, and so on—all of which must interact for sight to occur. Damage one part—detach the retina, for instance—and blindness can follow. In fact, the eye functions only if the parts are of the right size and shape to work with one another. If Darwin was right, then the complex eye had evolved from simple precursors. In On the Origin of Species, Darwin wrote that this idea “seems, I freely confess, absurd in the highest possible degree.”

Keep reading.

6 Comments on "Evolutionary Complexity: The Development of Elaborate Structures Without Darwinian Selection"

  1. Archie Dux | Jul 19, 2013 at 5:11 pm |

    I still think the explanation is incomplete. The whole eye thing for example. The only way an eye can develop out of a patch of light-sensitive cells is if those cells are connected in some way to the organism’s behavior. The eye in a complex organism is not just a receptor of immense complexity with lots of super-specialized parts, it is wired into a brain that is primed to do something with the information. All encoded on a DNA molecule, with the codes for different parts in different places on the string. Each molecule of human DNA has about 204,000,000,000 atoms that have to be connected in exactly that one way, and it replicates itself, over and over, with astonishing precision. Accident? Natural selection? Spontaneously generating complexity? It just sounds unlikely to me.

  2. I think it’s supposed to say “Irreducible” Complexity.

  3. InfvoCuernos | Jul 19, 2013 at 8:24 pm |

    There is a whole christian series on nutflix about all the “holes” in evolution. On the surface, the arguments sound good, and are usually based on complex systems that its hard to imagine would spontaneously evolve randomly- the one I remember was how a giraffe had to evolve a stronger heart to be able to pump blood up the neck further, so that the neck and heart had to evolve at the same time- but then they throw in a “because god made the earth and all the animals cuz the bible tells us so, so there!” and spoiled the whole damn argument.

  4. bobbiethejean | Jul 19, 2013 at 10:27 pm |

    Ahhhh, irreducible complexity. It’s only been debunked about 8 BILLION times but people still use it. So sad. So, so sad.

  5. Archie Dux | Jul 19, 2013 at 11:55 pm |

    I submitted a perfectly reasonable critique of this a couple of hours ago. Apparently,it wasn’t what the mods wanted to read and so was not posted. Conclusion: this site are just as full of crap as everyone else.

  6. kowalityjesus | Jul 20, 2013 at 12:55 pm |

    I think a good basis for understanding evolutionary complexity is: the more important it is, the more complex it is likely to become: how often do you use your eyes?

    For example, if Earth had not had an ozone layer, we would probably have much thicker skin to ultraviolet radiation. Grace of God granted such a jewel of a planet.

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