Eli5: Why do most gastropods have right side/ clockwise spiraling shells? What is the advantage?
In: Biology
There doesn’t have to be one. Evolution is not about creating a perfect design, it’s about creating one that works well enough. In this case there is no real advantage to having shell that spirals a particular way, it just so happens that that’s the way most originally evolved, and there was no pressure to change that design.
The answer as already been given (namely there isn’t an advantage, it just happened this way), but I would like to add that this kind of things is everywhere in nature.
[Amino-acids, the basic blocks of life, are chiral](https://en.wikipedia.org/wiki/Chirality_(chemistry)#In_biochemistry) (meaning they come in two symmetric versions). Almost all life on earth use left-handed amino-acids, and lot of our “chemical machinery” is also shaped to work only with these left-handed molecules. So if you could somehow synthesize a steak made of right-handed meat your body wouldn’t recognize it as food…
We don’t really know why it is this way, since the chemistry would presumably work just as well if it was the other way around.
[Chirality](https://en.wikipedia.org/wiki/Chirality) is also a thing in physics, with some processes having preference for clockwise or counterclockwise spinning particles for no apparent reason.
Latest Answers