in other words, the removal of loss of symmetry elements. In particular, henomena that nearly all biologists think of as "the formation of symmetry" are really examples of the destruction of symmetry. Thier conclusions have been very different from the intuitive, unexamined assumptions that biologists are used to! Biologists also speak many plants and some animals as having " radial symmetry" and regard this as a consequence of being sessile (non-motile), or of having sessile ancestors, but they do not make any systematic analysis of why this should be true, much less whether it is true.Īctually, for just about the last 100 years physicists, mathematicians and even chemists have been delving quite deeply into abstract questions of the classification of different kinds of symmetry, and the relationships between the symmetry of causation and the symmetry of effects. How logical is that? Do you share that view?īiologists often speak of embryos "developing planes of symmetry", sometimes meaning right-left mirror image symmetry, but other times meaning geometrical properties that are really examples of the loss or lack of symmetry (such as when animals are said to have "3 planes of symmetry", anterior-posterior, etc. People sometimes even conclude from this that if a biological or other natural phenomenon has pronounced symmetry properties, then the causation of such a phenomenon must involve crystallization of some kind. Everyone is familiar with mirror image symmetry, but there are many other kinds of symmetryĮveryone knows that the science of crystallography has made good use of symmetry concepts in classifying and explaining its subject matter.
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