Hello. I have always been confident in the fact Evolution based on the few bits of evidence I knew about and logical reasoning. However it is only recently it has started to amaze me even more, probably because of my studies of the complexity of the human body at school. And so I have started to read further into it.
This is a question focused specifically to the Natural Selection aspect of Evolution.
An organism that has a feature better suited to its environment that allows it to function will survive, while an organism that does not will die. And we see this everywhere, it is the whole basis of survival of the fittest. And the fact that the few organisms with these suitable features survived and the many without them did not is used as evidence for evolution.
So it is unintelligence design (to quote Dawkins) that determined the species better suited is the species that survives. However what is it that determines that any organism has a feature like that in the first place. It is a near impossible chance that some organisms slowly gained legs and managed to crawl onto land. Why didn't they all just not develop legs and be stuck in the water or die on land. And the fact that something so suited to an environment seems to develop again and again seems absolutely amazing.
So I really want someone to give me an idea of how this might happen. The best I can come up with is food supplies run short in an area of water and the creature is forced further and further into new areas, including land. Maybe only a few with a strange extruding blob of some sort could slightly drag themselves up and gather some food off the shore and then back into the water. And as generations went on these fish with strange blobs were the ones that survived, and the blob genes changed randomly and after generations again one with a slightly bigger blob went further into land. But then how does the chance of having a skeleton come into this? The fact that we have a skeleton, a completely impossible thing, to support our limbs and body, a completely impossible thing. And I assume there was a period of a species that could breath in both water and on land that allowed for this transition of habitat.
As you might tell I don't know much, and a lot of what I say might seem a bit ignorant. But I am new, and if you could try and explain this idea to me that would be great. If it's just a wall of words, I guess what I am asking is this: Evolution is not reactive, the organisms that nature gets wrong die off, but how did so many seemingly get it right for their specific habitat in a universe of infinite possibilities.
Thank you.