Natural Selection Doesn't Always Work...

[paw-paw]

So I have a lot of guppys in my tank and females are constantly giving birth to tiny fry. I decided I am going to leave the fry in the main tank so that only the fittest babies survive. Tho I must admit I can't watch the babies being eaten that is why I have females and males separated but because females can drop up to 7 times after being with a male the babies are still coming.
Anyway, most of the fry get eaten before I even notice they are n the tank, there are only two survivers, but the weird thing is...One of them has a deformed spine. His tail is bent upwards. Sorry, I am not good at describing...He/she seems to be doing just fine, he is a fast swimmer and tho adults chase the little ones (and eat what they can catch) he outswims them. Everytime I look at the tank I am expecting him to be missing, but he and his bud are just too smart and at the rate they are growing they will soon be too big for the adults to eat them.
I know people usually put fish with deformities down but I must say I admire him. He is a survivor, a true fighter so I just can't do it. I am sure he and his bud will survive. Anyway I have females and males seperated so will just keep that deformed fishly in a uni sex group so that he can't pass his genes to another generation...
I just wanted to share this with you, and in case this little one does start to show signs of pain or discomfort I will put him down...

 

[OldMan47]

Fish crazy, natural selection is a statistical process. It does not apply to a single individual and never can. It is about the chance that a youngster has to survive to breeding age and then breed successfully. There will always less well adapted youngsters who survive just by chance but on average, the ones better suited to their environment will survive more often than the ones less suited to their environment. I'm sorry you are left with a less desirable fish but it is almost unrelated to natural selection. Selection is macroscopic, specific individual survival is microscopic.