Constraint

Our world is populated by creatures of every variety, using different adaptations to survive in and even thrive in the habitats they call home. If a species cannot adapt to a changing environment it is doomed to extinction. This flexibility to change is necessary then for survival and thus any hindrance or constraint on flexibility should decrease the specie’s chances of survival. Shocking as it may seem, constraints are not only necessary for adaptations to occur but constraint within reason may actually drive adaptation.

In order for species to adapt, the organisms of the species must vary from one another allowing differential reproduction caused by natural selection to favor some traits over others. Those traits that increase the fitness of their organism are thus adaptations. If we took away all constraints there can be no form. Without even the slightest constraints such as base physical laws such as gravity, organisms would be an indiscernible cellular noise. Without form there can be no variation. The molecules of gas in a balloon are as nearly free from constraint. Looking at them, we can describe their state only as a generalization: pressure. There is no form or structure or variation, only average density. Without variation there is nothing on which natural selection can act and thus no adaptations can be formed.

Given too much constraint and a species will fail to adapt to its surroundings, however, given the constraint of body form and structure, small variations can accrue to create adaptations. Arthropods - insects, arachnids, and crustaceans - have become the most successful diversified phyla in the animal kingdom by exploiting the constraint of an exoskeleton. Their building constraint provides a tremendous platform for variation of form and thus makes them highly adaptable to a changing environment.