Emotions and evolution

[SaveMeJebus]

Originally Posted by Random

That's as good an Evol reason as any. Frubals. But what about emotions that run contrary to the instincts to surivive and propogate the species? Emotions that lead to self-destructiveness, for example?

like us.

[SaveMeJebus]

Originally Posted by Somkid

I don't feel it is dangerous, I used to be a very angry even potentially violent person I have learned to do away with these negative emotions and it has served me well for 23 years, when they arise I squash them right away and the feeling passes as fast as it came. I do not get excited or all "worked up" over anything because to me everything just "is" not good not bad not wonderful it just "is". I have found peace and I am content in my life, I have learned to stay on the "Middle Path" never to the left and never to the right.

BORING!!!!

[L0gic]

Emotions and motivation are very closely linked. To address the easiest question, no, plants have no emotions as far as I know. Plants are living creatures, however, they lack a brain as well as a central nervous system. To address another question, do animals have emotions. This will depend on one's view. If you recall the famous B.F. Skinner, a behavoirist, he would probably say we humans couldn't know exactly what an animal was thinking or feeling. However, others would probably disagree, such as myself. From an evolutionary perspective, one must try to grasp the concept of how could emotions increase reproductive success. Take for example, dominance or anger. This can increase reproductive success in a few ways:
1) It may allow a female to be attracted to the more aggressive male,
2) A more aggressive male would drive out a less aggressive male,
3) A more aggressive male would have greater success at acquiring resources to survive for itself, as well as presenting for a nupital gift to the female for courtship.

These are some of the possible results (yes, there would be more). As one can recall, natural selection would favour the aggressive or dominating emotion, hence, increasing it in a population of individuals.

The user, Random brought up a very good question: "what about emotions that run contrary to the instincts to surivive and propogate the species? Emotions that lead to self-destructiveness, for example?"

This is a very interesting question as what good could self-destructiveness do for a species? Well, I'll try to use an example to explain this. In peacocks, males are typically selected by the females due to their large, extravagent tail. The males with the larger tail tends to get the female. So, why is this related to self-destructiveness? If the male is to have a larger tail, they have a greater chance of being killed by a predator as their ability to flee is slightly compromised. This leads to the peacocks having a self-destructive behavoir, as their larger tails is a double-edged sword. It allows the males to have a better chance to mate with the female, however, it also limits their lifespan significantly. The female views the males with a larger tail as being stronger and more capable of protecting her and the offspring.

One can view this as being a self-destructive trait, however, it is favoured due to sexual selection.

That example may have not fully answered the question at hand. However, it is likely that the self-destructive behavoir may have some beneficial purpose. For natural selection to occur, one of the criterion is that the trait must increase reproductive success in some way. So, for the peacocks, the males' tails lead to a self-destructive behavoir as their tail basically leads to their death in most cases, yet, it allows for greater chances of courtship.

If by your question, you mean purposely harming one's self, unless it fits the criteria for natural selection, it won't be favoured upon. Suppose there was a species a. Also, suppose that the females of species a allowed males of species a to have courtship if the males caused some sort of harm to themselves, then a self-destructive behavoir (assuming it is heritable), would lead to greater reproductive success. Suppose members of species b came along, however, they didn't harm themselves. The females would not choose them as often to mate with.

The overall answer is that the self-destructive behavoir must be heritable and cause an increase in reproductive success compared to other members. In the cases of the peacocks and my fictious example, sexual selection is acting to cause an increase in the frequency of a trait the causes the self-destructive behavoir.

To the OP, as with the explanations to Random, the emotions must have some way of increasing reproductive success and must be heritable. If you were inquring about such emotions or behavoirs as hunger or thirst, those can be partially explained biologically. I say partially as hunger is still being investigated. It's not very simple, as Walter Canon (in 1912), did a study and came up with a theory that stomach contractions cause hunger. To his dismay, this was quickly abolished. However, I think the idea of hunger or thirst as a behavoir is not what you were asking about.