Behavior plus “Pathology” — the Origin of Adaptations?

Summary

The relationship of construction and behavior in the evolutionary process is discussed on the basis of comparison of malformed bills of avian species with the normal, but specialized bills of other species. The following insights emerged:

• 1. 1. Construction and behavior can be evaluated only on the foundation of their interactions.

• 2. Construction and behavior can vary independently from each other within certain limits.

• 3. As a rule, behavior seems to act as a selective force on the variants of the construction. This means that the organism produces an own canalizing (selective) factor in addition to, and reaching beyond the canalizing limitations of the mere constructional constraints of its coherent system.

• 4. Through its behavior the organism involves parts of the environment in its activities. The concept of adaptation is meaningful only in this context.

• 5. The environment cannot bring about organismic variations; the environment is not creative, it can only eradicate.

• 6. The insight that behavior channels construction can be helpful in attempts to reconstruct the evolutionary process, even if it sometimes helps only to understand why a certain reconstruction cannot be achieved.