Evolution refers to a genetic change in the population of an organism, but the whole process is very complex. It can be difficult to understand concepts and jargon like "natural selection" and "survival of the fittest." Variations in DNA throughout generations can result in permanent changes in the organism’s gene pool.

In SciShow’s new video, “Common Misconceptions About Evolution,” host Hank Green breaks down the basics of evolution and talks about the discoveries of Charles Darwin — who was not actually the inventor of this theory. The scientist examined prior research from peers, and only introduced the idea of natural selection. He also popularized the idea that new species came from existing species.

Read: HIV May Date Back Millions Of Years: The Evolution Of Retroviruses

When talking about survival of the fittest, it doesn’t always mean that the physically strongest survive.

“Even if you totally understand natural selection and survival of the fittest, it’s easy to think that evolutionary change is always good for the organism it’s happening to,” Green explains in the video.

Sometimes, genetic mutations happen for no reason at all, really. This is because a lot of our DNA doesn’t do much, and even the important regions usually have room for a little flexibility.

Want to know more about scientists’ theories behind human evolution? Watch the video above.

See Also:

Human Evolution: Origins Of Our Big Brains, How Our Evolution Continues

Future Of Human Evolution Suggests We Will Develop Smaller Brains And Healthier Bodies