German scientists figure out the evolutionary origin of the human eye.

One of the most common arguments proponents of Creationism and Intelligent Design like to put forth as a flaw in Evolutionary theory is the supposed irreducible complexity of the human eye. The basic argument being that something as complex as the human eye couldn’t possibly have evolved by random chance so it must be the result of intentional design. Even Darwin found the idea of the eye being the result of evolution a difficult idea to swallow and it’s been a favorite target of his critics for decades. Now a German research team at the European Molecular Biology Laboratory are reporting that they have elucidated the evolutionary origin of the human eye in a paper published this week in the journal Science.

Researchers in the laboratories of Detlev Arendt and Jochen Wittbrodt have discovered that the lightsensitive cells of our eyes, the rods and cones, are of unexpected evolutionary origin—they come from an ancient population of light-sensitive cells that were initially located in the brain.

“It is not surprising that cells of human eyes come from the brain. We still have light-sensitive cells in our brains today which detect light and influence our daily rhythms of activity,” explains Wittbrodt. “Quite possibly, the human eye has originated from light-sensitive cells in the brain. Only later in evolution would such brain cells have relocated into an eye and gained the potential to confer vision.”

The scientists discovered that two types of lightsensitive cells existed in our early animal ancestors: rhabdomeric and ciliary. In most animals, rhabdomeric cells became part of the eyes, and ciliary cells remained embedded in the brain. But the evolution of the human eye is peculiar—it is the ciliary cells that were recruited for vision which eventually gave rise to the rods and cones of the retina.

If this holds up under peer review it’ll be a major step forward in our understanding of Evolution and a major setback for a lot of “God did it” proponents who hope to get their “alternative” theories taught in schools. At the very least it shows the human eye isn’t anything close to being irreducibly complex and that, unlike Intelligent Design, the theory of Evolution continues to, if you’ll pardon the pun, evolve over time.

6 thoughts on “German scientists figure out the evolutionary origin of the human eye.

  1. Huh, I thought this was already known as in the eye evolved from cells that are sensitive to light. There are organisms today that have this light sensistive cells. Unless of course the article is mentioning something else.

    Actually the eye is not an argument for intelligent design but rather it is an argument against it. The reason is that the make up of the eye is not perfect. The way everything is lined up is in a total (but functioning) mess. And it is not efficient at all and makes one prone to damage. An analogy is that you want to get something from point A to B. But instead of a straight path, one goes from A to C to D to E to Z to F back to C to H then to B. If there was any intelligence in the design one would omit the rest and just go from point A to B.

  2. “Actually the eye is not an argument for intelligent design but rather it is an argument against it. The reason is that the make up of the eye is not perfect.”

    I suspect that the ID folks consider us to be their designer’s best effort. Well sorry, the Octopus may have us beat in the retina department.

  3. That is really interesting…what I want to know is where did the light-sensitive cells come from, and why.
    Any thoughts?

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.