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Originally Posted by Bake_McBride What is the prevailing evolutionary explanation for each of the following:
1. The intense pain experienced by women during childbirth.
2. Homosexuality
3. Addictive self-destructive behavior
4. Belief in fanciful religious doctrines/stories
5. Cancer |
These are pretty random questions but interesting none the less!
1) I don't think there is a reason as much as there is no selective pressure not to be in pain. It hurt as it is a physical trauma but pain doesn't reduce the evolutionary fitness i.e. it doesn't stop the baby being born or the mother having any others. Also we are bipedal and have large heads which doesn't help matters it is an evolutionary trade off between a large birth canal for easy labour and being able to walk.
2) Several theories
a) the gene which makes males gay also makes females more fertile. Therefore it aids offspring production 50 % of the time
b) Gay males are statistically the younger males in the family- older males (in the past) would have first access to females as a resource- they would be older and stronger. Therefore a younger male may aid the passing of his own genes better if he helps his sisters raise children instead of wasting his energy trying to reproduce and compete with his brothers.
Another theory explaining this phenomenon is the older males destroy competition by changing the womb's chemical composition to make male siblings gay.
c) Female homosexuality could be explain in female bonding increasing their offspring’s survival - two mums!
3)Addictive behaviour
This is down to reward pathways in the brain. Drugs are not natural and override normal chemical levels. Addiction to food is down to the body regarding food intake for obvious reasons. Addiction to self harm is form endorphins released upon pain to suppress pain. Addiction generally biologically a normal system that has been disrupted in some way. I'm not sure what evolution really has to do with this unless you want me to go into the evolution of the brain and reward systems? Could take a while....
4)Religious belief/stories. Very useful for children to believe everything they are told- suppose they do not believe that eating deadly nightshade is well... deadly. Bam out of the gene pool there. Humans retain childlike characteristics we are neonates. It is useful as it means we retain our curiosity and playfulness, this has aided our spread as a species. Religion can also be thought of as a meme (thanks Prof Dawkins)- a cultural gene. It was a cultural idea which spread itself as it destroys other ways of thinking and has systems in place to spread itself. Personally I believe it has nothing to do with evolution it is just a highly effective means of controlling people.
5) Cancer- is cells dividing out of control. Evolutionary we have developed means to stop cancers in our immune systems and cell checkpoints to stop uncontrolled growth. However it only takes a couple of mutations in important controlling proteins by chemical, oxidation, radiation, mutagens all of which we encounter everyday to cause a cancer. The reason these things don't cause cancers all the time is we have means of stopping it. As we age our immune systems wear out and we gather more random mutations that is why people are more prone to cancers when they get older.
It was a giant question so these are just quick synopses post back if you want to know more about any of them.
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