Sharks teaching us about "Survival of the Fittest"

There is something about sharks that I dislike.  Possibly because I was traumatised by "Jaws" the movie when I was a kid but, watching it as an adult, I don't understand why I was traumatised by it.  The plot was believable, the acting was poor and unrealistic...  BTW, I did not watch "Sharknado" either because the plot is too unrealistic and, yes, the acting was poor...  I would rather watch "Game of Thrones" than "Sharknado" any day. 

In this post, I would like to draw your attention to sharks...  not because I am trying to conquer my trauma...  but rather because I find them fascinating on many levels... 

Firstly, in many living species, the female chooses to mate with the best male around.  However, the female sharks in the following article (http://phenomena.nationalgeographic.com/2013/04/30/shark-dads-lose-babies-to-unborn-cannibal-siblings/) actually mates with different males; then "chooses" (I don't know how they do it) which sperms will fertilise her eggs.  Now, she may well choose the sperm of more than one male.  That being the case, the offspring will have to fight for survival or, some may read it, nature makes its selection of the winner.   Now, this fight involves cannibalism -- so please move away from "Hunger Games" type storyline because there is only one victor for each womb (there are only two wombs).

It fascinates me that these adult male sharks that mated with the adult female sharks obviously had fought their way from embryo to adulthood.  Yet how interesting that some of these males may somehow become excluded from the future gene pool because they are deemed by the female sharks and nature to be less fit (if not unfit). 

Next leap of thought: "Does that mean that the gene pool over time will be quite restricted?"  If the gene pool is restricted, does that not mean that the specie will really be better or worse?

While scientists are busy with genome and other associated research, the intellectuals are battling out the ethics.  In the midst of it all, there has been much talk about creating the perfect human.  As humans continue to push the scientific-medical frontier for a chance to play god and away from nature, will we one day have a limited gene pool in which some of us will completely be exterminated while the best of us remains?  If this restricted gene pool comes about, does that not also mean that in the event of a flurry of viral or otherwise mutations, the human specie may be wiped out?  Maybe I am straying too far from my topic...  but no harm thinking...  afterall, all my thoughts can co-exist because no one thought can cannibalise my other thoughts...  Oops, another thought is whether some mother sharks may suffer from antenatal depression?

You may also like to read:

• http://www.nytimes.com/1982/12/07/science/in-shark-womb-fetus-cannibalizes-rivals.html
• http://en.wikipedia.org/wiki/Cannibalism_(zoology)

If videos are for you, please watch:

• https://www.youtube.com/watch?v=wzPxkmtqryI