Evolution by Natural Selection

If you want to understand evolution by natural selection it really is just a logical system. We know that genes exist and they're passed on from parent to offspring. Different alleles are better suited for life in different environments. As long as there is reproduction there will be evolution. It's the only way that can happen. The best bowl constrictor is going to die in Antarctica; the best penguin is going to live in the Amazon. If those traits benefit me tremendously and I have lots of babies because of it then over successive generations the population will shift in this way.