Science Forums 2

[Boerseun]

Animals evolve certain traits over immense stretches of time, because it's in some way beneficial to the species.

In breeding season, males posture, threaten and intimidate their fellows for access to females. Individuals stiffen their hairs to increase their apparent size, looking more threatening. Some reptiles inflate large flaps in their cheeks to achieve the same goal. Deer grow huge antlers, buffalo head-butt, lions charge and slap each other, but very rarely does this aggression result in violence where any individual gets seriously hurt - although it wastes an enormous amount of resources.

But there's an interesting off-shoot of this whole process. Amongst the pit vipers of America, for example, competing males rear up against each other, entwine, and try to push the other over. The first to fall is the loser, and he slithers away. But the females also emulate the male's intimidation strategy prior to mating: they also rear up and push against the males. Males who have lost their last battle of strength against another male, seem to have all the energy sucked from them - they make a halfhearted attempt at pushing, fall over, and despondently slither off. It seems that it takes them days to get over the humiliation of their defeat. Not interested in wimps, the female will then turn away and go and look for another more deserving, stronger male.

This process serves a very good purpose. It cuts down on unnecessary violence between males which might result in cuts (about as bad as intraspecific violence gets) which might get infected, leading to the individual's demise. The loser basically "advertises" his submissive status to the females by only putting up a half-hearted fight, and being pushed over by females half his size.

And this brings me back to the thread title.

Could it be that depression, which seems to be a negative trait, clearly not one to be selected for, has a positive role in evolution? Whatever the cause might be, once you're depressed, you make for very bad company. It's harder to pick up girls when you're depressed, as opposed to picking up girls left, right and center when you're happiness incarnate. Depression might be a sign telling females to "Stay Away - This Guy's a Loser" without you having to slug it out with an Alpha Male in front of the female, so that she can see you establish your status in the dominance hierarchy for herself? Basically, depression cuts down on unnecessary violence, making for a more stable society.

Of course, the reasons people get depressed vary. Even leaders in society (alpha males) get depressed. Sex and procreation is clearly not always the cause. But what I'm saying, is that the mechanism causing depression might have originated as part and parcel of establishing and maintaining a dominance hierarchy, saving on unnecessary bloodshed in that you have your status in the hierarchy pasted on your forehead through your depressive attitude and despondent nature without having to get involved in a fight every time a girl strolls by.

Makes sense?

If it does make sense, how would that trait then be bequethed to the next generation, except through kleptogamy? Which then makes for a completely new case for the evolution of criminal behaviour, and the shunning of the dominance hierarchy altogether...