If cut a cut down the middle, both halves are symmetrical.

Why is it that most animals are symmetrical?

Is there an energetic reason for this? (as in, it is energetically favorable to create the same thing twice instead of making something new)


marked as duplicate by mgkrebbs, David, Community Aug 15 '17 at 20:50

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


Intuitively, symmetry is useful for balance. A weight-nonsymmetric animal would have to expend additional energy to keep itself balanced (and this would also increase neural complexity for maintaining balance).

Mirror-image pieces only have to be coded once in the genome as a rule-of-thumb, allowing reuse of (mostly) the same genetic pieces with a few orientation and growth-origin markers thrown in. If you put vastly different parts on each side, you have to encode them (making the genome larger with more opportunity for mistakes and harmful mutation)


Not the answer you're looking for? Browse other questions tagged or ask your own question.