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This line confused me as a place to end the answer to this question. For instance, a creature with a tail is still bilaterally symmeteric. Us human males are s
by elif 7y ago
This line confused me as a place to end the answer to this question.
For instance, a creature with a tail is still bilaterally symmeteric. Us human males are still bilaterally symmetric. A full third leg would still be bilaterally symmeteric.
- Aardwolf 7y agoIt would need toes of the same size on each side and a symmetric knee plus muscles to control it, I think it would need a leg and foot or hoove design completely independent from the outer ones, it couldn't copy or reuse the existing design, so less likely to evolve. But if the kangooroo tail counts as a leg, it's indeed very different, but symmetric.
- kijin 7y agoYeah, it would seem that we have plenty of three-legged animals already. A stout tail is what you get when you try to make a third leg that is perfectly symmetric and optimized for being positioned in the middle.
- coldtea 7y ago>A full third leg would still be bilaterally symmeteric. Not necessarily. You could have 2 legs on each side, and a symmetrical looking leg (e.g. hooves, or human like but with 2 toes on each side) on the center.
- perl4ever 7y agoYes, things like starfish start out as bilaterally symmetric, both developmentally and evolutionarily. But according to what I was just reading, the way a five limbed radially symmetric creature develops is not by growing two halves where each half is two and a half limbs. What echinoderms supposedly do is the left half of their body grows disproportionately and the right half gets absorbed, and all the limbs grow from the left half. In any case, if you do think it possible to also grow a third leg by halves, then presumably you are even more in agreement that bilateral symmetry does not prevent odd numbers of legs.