Ah I get what you’re saying. My point is that yes, some other type of shell probably selected out and this one wasn’t. Maybe it was dumb luck, maybe it was a sl

Ah I get what you’re saying. My point is that yes, some other type of shell probably selected out and this one wasn’t. Maybe it was dumb luck, maybe it was a slight advantage in a very specific condition that allowed it to persist, but ultimately we can only theorize.