Chance or design?

Tree of life

In this context, we must distinguish three things:

1. The scientific theory of evolution, which is strongly supported by data from other sciences, such as embryology, comparative anatomy, paleontology, biogeography, or molecular biology (DNA analysis).
2. The claim that evolution is a consequence of pure chance, which is not a scientific theory, but philosophical, although its supporters claim that it is scientific.
3. The assertion that evolution is an example of design, which is not a scientific theory either, but philosophical. The supporters of intelligent design argue that it is scientific.

To solve this dilemma we would have to answer one of the following questions:

•         Is there a way to prove scientifically that evolution is a consequence of chance, rather than design?

•         Is there a way to prove scientifically that evolution is a consequence of design, rather than chance?

How the eye evolved

Let us reason about this problem by answering a few questions.

1. Which part of the eye is most essential? The answer is obvious: the retina. If light cannot be detected, the remainder of the eye is useless.
2. Can a retina, on its own, without the rest of the eye, play a useful role? Obviously, yes. Many groups of not too complex animals have ocelli, photo-receptor cells that just react to the presence of light, but cannot form images. Of course, perceiving the presence of light offers advantage against being totally blind. The proof of this: ocelli have appeared independently in at least 40 different animal groups.
3. What is the next step? We also have traces among current animals. The Planaria is a Platyhelminth (flatworm) whose ocelli are located at the bottom of a concavity in its body. Thanks to this, the Planaria not only detects the presence of light, but also, to some extent, the direction it comes from. It is also obvious that being able to perceive the direction of light provides advantage to those who can, against those who cannot.

The eye as an argument about evolution

Schematic diagram of the human eye

The vertebrate eye consists of five parts: cornea (a transparent insulating layer); aqueous humor; crystalline lens (a lens surrounded by muscles that make it possible to achieve a variable focal length); vitreous humor; and retina. The light passes through the cornea and the aqueous humor, is focused by the lens, goes through the vitreous humor and impacts on the nerve cells of the retina, which generate electric signals that the optic nerve transmits to the brain, which forms from them an image of the external world, where the light rays came from. The brain even turns the image around, as it is inverted when projected on the retina.

The complex structure of the eye has always been a problem for evolutionists, and an argument for those opposed to the theory of evolution. Darwin, in Chapter 6 of The Origin of Species, whose title is significant (Difficulties of the theory) dealt with the problem of the evolution of the eye in the following words:

What happened to the predictions for 2017?

Drone

At the end of every year, many predictions are made about the following year. This applies especially to politics and the technological field. In this blog we are not interested in politics, so we’ll talk a little about technological predictions. What happened to those that were made for 2017 near the end of 2016? Have they been fulfilled?

This question is difficult to answer satisfactorily (with a yes or no), for those who make predictions usually do them on purpose in an ambiguous way, so the next year they’ll be able to say that they were right. For instance: