Wednesday, June 27, 2012

Digital Universe Atlas and evolution of human eye

Human eye (ref)

The visible part of the spectrum is that region of the EM spectrum where the Sun emits its peak intensity. This is the main reason that humans have evolved to see in this region of the spectrum. Our eyes can simply be thought of as filters that see only in the visible part of the EM spectrum. With a prism, this region can be split into its component colors from red to violet. Visible light reveals the main stellar populations in galaxies.
Digital Universe Atlas Guide p. 216
The Guide accompanying the Digital Universe Atlas is a shining example how to teach astronomy and to make students understand and evaluate scientific evidence, the meaning of observations and also the limitations inherent in various data sets.

But in the otherwise excellent short introduction to various types of electro-magnetic radiation the Guide ventures in a rather unfortunate manner to the world of Biology.

"This is the main reason that humans have evolved to see in this region of the spectrum."

Dragonfly eyes  wikimedia  .

The statement is not similar to the strictly scientific style of the Guide approaching an introduction to Mathematics or Physics. For human eyes are deep in their sockets already in the earliest known skulls of our species some five million years ago - how much they have evolved since is difficult to say as the tender organs do not survive. Also the eyes of our cousins the chimpanzees are highly developed.

As for the first living creatures able to see something in sunlight upon the Earth we know very little about the development for the same reason, the fragility of eyes. The first eye fossils are rare and date to the Cambrian period. These are already very complex, f.ex. the 36.000 lenses working in harmony in the eyes of the Anomalocaris that were discovered in 2011 myBlog

The quoted text from the Digital Universe Atlas Guide represents a particular world view and there are scientists who think that the appearance of these extremely complex organs some 530 million years ago can be explained by referring to the need of organisms to have them.

I beg to disagree.

No to Christian science!
I also disagree with the view of Albert Mohler, President of the Southern Baptist Theological Seminar, who in 2004 wrote about the so-called Stephen Meyer controversy.

If natural selection is the only accepted method in scientific study of evolution then the appearance of Cambrian eyes is not easy to explain. The alternative is not to suggest that the explanation is the Intelligent Design by some supernatural being that cannot be studied. The Holy Bible to which Mohler refers does not offer any shortcut to knowledge about the nature God has created and those who believe in it can actually hinder scientific progress.

At the moment it seems that the most promising way forward in studying the origins of eyes is to learn more about DNA. True, the study of the genetics of eyes is very complicated and takes very hard work. Amazing achievements have already been made in this line of study by biologists, for example Trevor D. Lamb and his team myBlog

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