Letters From Darwin - The Evolution Of The Eye

Schroedinger told us that a cat could be both dead and alive at the same time, and we were fine with that.

Einstein told us that light can bend and that gravity can slow down time, and we just shrugged and said, OK, that's cool.

Jenner told us we could fight a disease by injecting a little bit of it into our bodies and we were A-OK with that one too; well, some of us still struggle with that one, but you get my point.

However when Darwin tells us that every living being on the planet didn't just magically appear, but rather came to be via an achingly slow process of gradation and . . . woah! Hold on justa cotton-picking-minute! You're crazy, it's obviously not a slow process, it's divine magic I tells ya!

Common Arguments

I truly believe that the theory of evolution would actually be more widely accepted if more people had actually read Darwin's first book on the subject; On The Origin of Species By Means of Natural Selection, referred to hereafter as, Origins.

The internet is rife with various questions and arguments that are meant to put doubt on the theory of evolution; or show that the theory is somehow just opinion, rather than stone cold fact.

There is nothing wrong with questioning evolutionary theories, the only problem is, these questions have been answered, however they are postulated as if they are somehow still a great mystery.

One particular question I've seen repeated is:

How can the theory of evolution deal with something so complex as an eye? That's like asking me to believe a hurricane could blow through a junkyard and create a perfectly working aeroplane. Plus, an eye is only useful as an eye, how could you possibly survive with an incomplete visual system?

So, now let us see how the author of the theory himself answered these and many more questions.

Darwin's Gambit

~ Extract Origins, Chap VI.

Origins of extreme perfection and complication. - To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree.

So as we can see from above, Darwin himself asked the question long before anybody on Youtube did. The eye is absolutely perfectly suited for the job, and is multi-faceted. Even to Darwin, this at first seemed to big a question for natural selection to answer. Extract Origins, Chap VI. cont.

Yet reason tells me, that if numerous gradations from a perfect complex eye to one very imperfect and simple, each grade being useful to its possessor, can be show to exist....then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.

So what Darwin is saying here, is that if we find simpler and simpler versions of the eye, going back gradually from complex to basic. Then that would hold in line with the theory, and our preconceived ideas would be wrong.

At this point Darwin points out that finding such eyes in the fossil records would be next to impossible, seeing as such creatures would have lived such a long time ago as to be buried far deeper than we could ever venture.

So he says that we are stuck with looking at creatures from similar genus that are around today. This wasn't a problem for Darwin, as he had plenty of sea specimens from the same evolutionary branch to observe. Extract Origins, Chap VI. cont.

In certain crustaceans, for instance, there is a cdouble cornea, the inner one divided into facets, within each of which there is a lens-shaped swelling. In other crustaceans the transparent cones which are coated by pigment, and which properly act only by exuding lateral pencils of light, are convex at their upper ends and must act by convergence; and at their lower ends there seems to be an imperfect vitreous substance.

With these facts, here far too briefly and imperfectly given, which show that there is much graduated diversity in the eyes of living crustaceans, and bearing in mind how small the number of living animals is in proportion to those which have become extinct.

I can see no very great difficulty in believing that natural selection has converted the simple apparatus of an optic nerve merely coated with pigment and invested by transparent membrane, into an optical instrument as perfect as is possessed by any member of the great Articulate class.

Here Darwin is talking about the eyes he has observed in certain simple sea creatures of the same genus. He talks about how he has seen with his own eyes, different stages of an eye in different species.

After viewing many such examples, he came to the conclusion that if there are living examples of one type of eye getting slowly more complex. Then it only logically follows that there would have been many examples of the same thing in slowly evolving, now extinct, vertebrate species.

The Wonder Of Isolation

So we can see that Darwin himself, observed that the eye did not just pop into existence, rather it slowly developed from one species to the next.

These Letters From Darwin, have been inspired by some of the great comments I got on one of my recent posts: Surviving A Post Truth World - Fighting A War Between Reason And Superstition.

While replying to one of the comments, I came up with an analogy that I feel is very useful when pondering the ins and outs of natural selection, so I'd like to share the slightly modified version with you in an up coming article I have entitled Letters From Darwin - An Evolutionary Coin Flip .

Extracts taken from Chapter 6: Difficulties With The Theory. Full explanations contained but not cited.

Cryptogee

Letters From Darwin - The Evolution Of The Eye

Common Arguments

Darwin's Gambit

The Wonder Of Isolation

Further reading:

Extracts taken from Chapter 6: Difficulties With The Theory. Full explanations contained but not cited.