We have natural selection that causes speciation and makes animals and plants super suitable for their environments. The reason it happens is because all species want to survive and thrive and reproduce. The question then is not just why but how is it that it is necessary for life on earth to want to thrive and survive and reproduce? Since DNA we now just say it's all called for in the basic code of life as we know it. but why do animals and plants feel compelled to survive and then thrive to eventually reproduce? we could have some tautological explanation that says it all happens because that allows survival and reproduction. Or we can go back and blame it on the DNA. easy to do but reality is nature seems to have intelligence and that seems to go beyond just DNA . DNA has chemical reactions underlying its workings. That's coded too. Do the sub dna chemical reactions also want to survive and reproduce themselves? probably because most physicists believe entropy is at work.
We live in a coded universe and therefore it really is an intelligent universe. We know all about code and how it runs our computer systems like Microsoft programs on all our computers...that code is valuable only because it can be reproduced on disks and by other means and put on countless numbers of different machines of different types. Code is about communicating and disseminating information while also organizing it or having an effect on things outside of the code in the surrounding environment. coding then is key to understanding why it is and how it is that animals and plants naturally must survive and thrive and reproduce. its a code specific reality. Its the reality of coding.
Now I am not arguing for anti Darwinism I am completely in support. nor am I a believer in intelligent design except to say those people do actually have a point. They just don't understand that codes exist so they can manage coding other things.