A real bank robber acts to his individual benefit at society's collective cost. A better, more basic example is two people who have the habit of exchanging nods whenever they pass. But that first nod might actually be a nervous tic, or some other kind of dysfunctional muscle reflex. Or the man being nodded to may be from another place, and is being mistaken for someone else. This may go some way to establishing that a handle can exist without a marker.
Males have a higher metabolic rate than females.
However in evolutionary terms post-menopausal females are completely redundant, and no distinct evolutionary reason for female longevity has yet been determined. An Attempted Pun on the Open Legs Signal One interesting incident which didn't make it into these accounts was a pun on the Open Legs signal. On the Wibautstraat in Amsterdam were a couple of large bridges which were often raised to allow ships through. If I remember correctly the painting featured a short skirt and white knickers. It was a pun between the open bridge and a woman's open legs and a rather good joke on Amsterdam's sexual permissiveness.