How to understand evolution (natural selection)

I'm making this because I was just in a discussion about it with someone. I'm amazed at how many people don't understand the basics of evolution.

I also want to point out that this guide, like the discussion I was in with my friend, wasn't about religion. Many use it in religious debates but in truth many on both sides agree about evolution

The misconception is that they think evolution means one species spontaneously changing into another. That it cannot and hasn't been directly observed. All these points are false.

The process of evolution is called natural selection. Some argue that they are the same thing but in reality natural selection is the process in which evolution occurs. I'll use a common example.

Like every species. The peppered moth lived in a variety of white and black colors. They didn't have much trouble hiding from predators because they blended with the different colored of trees.

Light ones where well hidden on light trees and dark ones where well hidden on dark trees. Even birds had a hard time seeing them. The white one on the right would be easier pray in this image.

But then came the industrial revolution in an area the peppered moth dwelled. All the smoke and smog made the trees darker. Giving the light ones fewer hiding places.

As a result the lighter ones where eaten more often than the dark. They couldn't reproduce as fast as the dark ones. Eventually there where very few light ones and many dark ones in this area.

In this diagram you see the process. The medium shaded ones lasted a while. But eventually the darkest ones where the only ones left. All because of a change in environment. This is natural selection.

Are the lightest ones and the darkest ones a new species? No, they're both peppered moths.

Now for another example that we observe in a very short period of time. Even yearly. Have you ever wondered why we have NEW flu shots every year? It's because of evolution.

Or why doctors don't just prescribe antibiotics for every cut or bug you might get? It's because of evolution and natural selection. Imagine the different moths I just mentioned where viruses?

Our bodies contain many virus cells (using basic terms here) that have a variety just like the moth colors.

One will be the dominant one. There are many more of this particular one and your body has a harder time fighting it. So we attack the dominant one with vaccines, antibiotics and other drugs.

These "drugs" are possible for us to make because we can test, observe and to some degree "predict" the effectiveness of these drugs partly because we understand the process of evolution.

So when we kill off the dominant one. Guess what? There's another one that was in second place and it now has less competition and can flourish. So after some time of this we'll need a "drug" that's…

Made to attack this new dominant bug. Hence, we need to design a new "drug" that's aimed at this new dominating virus. Evolution observed and at work.

What about this "missing link" they alway talk about? Well the best I understand it is this. To be classified as a "new species" they must be able to reproduce and create its own species.

We've cross breed many animals but the offspring are usually not able to reproduce. If someone smarter then me knows different please let me know but that's my perception of it.

Take for example the Mule (offspring of a male donkey and female horse) can't reproduce although there have been exceptions. Who knows. Maybe someday they will branch off and be a seprecate species.

The missing link would be when two species where similar enough to mate and produce offsprings of their combined species. And the offspring can flourish in numbers to produce its own species.

Anyway after the discussion I was in I decided to come here and share at least some of the basics. I know I'm no scientist or biologist. But I don't see evolution as something to believe in or not.

It's something we've assumed by observation, tested to verify, and continue to study. All evidence and tests confirm it to be true and we make use of this knowledge to better our chances of survival.

So as you can see. If someone says "a bird can't turn into a kangaroo". You'll know that that's not what evolution even suggests. Because those species have no link.

Of course most drastic changes take thousands or even millions of years. Consider how fast a society of moths changed. Imagine that society in a million years when more environmental changes occur.

If you consider how many species we have on earth could have common ancestors that are vary different then they are today. The world is constantly changing. To servive a species has to change with it.

I know this is a touchy subject for some people, though I can't understand why. But I hope no one minded it. Thanks for taking the time to read it.