Symmetry of Species

Depends on what level of organization you're talking about. Single-cell organisms aren't symmetric. A lot of organisms are radially symmetric (e.g. starfish). Go to google and ask something like "why are most organisms symmetric?". Here's one that talks about it: http://www.eb.tuebingen.mpg.de/dept4/meinhardt/web_org/hy-hea-brain.htm

adult halibut or flounder?

Re: Symmetry of Species


It's an interesting question. Sponges are asymmetrical. And a few other thing are as well, but they are certainly in the minority among living things.

Early cells may have evolved as a result of DNA incorporation into small bubbles in lipid solutions. Since bubbles are symmetrical, there might be a tendency to follow a pattern. Also, water has characteristics which lead to symmetry (hexagonal bonds split symmetrically).

Rather than simply looking for exceptions to the rule of symmetry in biology, I suppose the real question is, "why the preponderance of symmetry".

Well, I think this is because its a more efficient way of encoding...so it allows the dna to hold more data. also if you have different dna segments representing both sides, then an evolutionary change that affected both sides would be twice as improbable