Domesticated animals and plants are evidence of evolution. Seasonal bacteria, a flu, is an evidence of evolution. Evidence is all around us.

What the white coat fellow fails to understand is that variation, diversity is the basis of evolution. A species with large diversity has more chance of one of it's variants being more suited to survive the changes in the environment and living (feeding, breeding) conditions.

If one or only few variants of the species survive the change in the living conditions, and all others die out, that single variant naturally begins to mutate variations of it's own as it seeks to spread beyond it's original habitat, and the whole thing repeats. As surviving variants get ever more distinctive from each other, they lose the capability to interbreed and thus new species came to exist.

It doesn't always happen, sometimes living conditions are just too perfect in it's habitat and too unfavorable outside it's habitat and it doesn't manage to expand to another habitat for various reasons. If that habitat doesn't change, it's unlikely there will be many variations because the current variant is the most suited for living in the present habitat, and a species may remain mostly unchanged for a long time. If it's habitat suddenly changes, and there is no variation to compensate for it, entire order of species goes extinct.

It's hard to grasp how someone can doubt something so simple and logical, something which doesn't only happen with living beings. The same thing happens with... well objects in our surroundings. Even ideas. Most things evolved from something before, if not directly, then as an inspiration. But that's more into the realm of philosophy.

Now, I understand that religious people reject evolution because it goes against their beliefs, they fear that if they accept something outside the faith, their entire system of belief will shatter. But if you're not a religious fanatic, evolution should be common sense.

Well, at least if it's properly explained to you, unfortunatelly evolution tends to be poorly taught. I also wouldn't believe that things simply change from one to another magically because they must unless someone properly explains how exactly it happens. And that is seldom explained simply enough. So many people who do accept evolution, without understanding it, do it because someone smarter told them to, and that's same as being religious fanatic.