by Xiang Xiang Liew

Created on: December 14, 2009   Last Updated: December 16, 2009

The argument from design is traditionally used as support for the existence of a creator god. One form of this argument states that since organisms or biological structures are so complex, beautiful and perfect, they have to have been designed by a supernatural being. However, the fact is that organisms do not necessarily have optimal design.

There are many reasons for this, one of them being the fact that evolution selects for designs that enable organisms to survive and reproduce. Therefore, any design that allows an organism to do so will be selected for, even if it is not the most optimal or effective or perfect design.

Taking the evolution of the eye as an example: camera-type eyes are superior to compound eyes in almost every way, with higher resolution, better light-gathering powers, and so on. However, organisms with compound eyes are abundant in nature, such as insects which would technically benefit from having a better eye design such as camera-type eyes.

This phenomenon, in which optimal design is not achieved, is caused by the fact that having compound eyes is sufficient for organisms to survive and reproduce. Boyd and Silk state that in the early state of eye evolution, where eyes were merely shallow cups of light-sensitive tissue, either multiplying “the number of small photoreceptors, each in its own cup”, or increasing “the area of sensitive tissue within each eye”, would have been equally valid strategies for increasing the survival ability of the organism (79).

Therefore, compound eyes might not be the best or optimal eye design, but it still allows the organism to live long enough to get its genes into the next generation, and this was true especially in the early stages of evolution.

This statement highlights the fact that we need to bear in mind that certain designs are optimal in the environment in which they evolved, but not necessarily in the current environment in which the organism is situated in. A human example is our predisposition towards liking sweet and fatty foods.

This trait was conducive to survival in the ancestral environment where food sources were scarce, but in the current environment, where many countries have sufficient food supply systems in place and people usually have access to more food than they need, this craving for calorie-rich food is bad for our health and can lead to various diseases like hypertension and diabetes.

Of course, organisms are continually evolving in response to changing

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