Evolutionary changes by Natural Selection is: Slow, Gradual changes over a lengthy period of time. From a common ancestor, leading to all modern life on Earth today. Including Humans.
It takes time, a long time for the slightest change to take place.
Evolutionary changes are still evident in and on the modern human body. Features that once in the Human history have had a definite useful purpose, but no longer have any significant use, for example:
- The Wisdom Teeth (Third Molars): Earlier in human evolution, humans needed an extra set of molars to make the mouth more productive with chewing raw meat, nuts, tubers and leaves, the body lacked the ability to sufficiently digest cellulose which made the extra set of molars particularly essential. Over time our dietary requirements changed, making our extra set of molars useless.
Evolution may be slowly proving the uselessness of wisdom teeth, as thirty five percent of modern humans now do not grow their third molars. Indicating the wisdom teeth may be evolving out of existence.
- Appendix: modern humans have absolutely no use for their Appendix. Most scientists agree with Charles Darwin’s notion that the appendix was useful for processing cellulose, found in the earlier leaf rich diet. Over evolutionary changes, the appendix is likely to stay for a very long time, doing absolutely nothing.
- The Coccyx: commonly known as the Tailbone. A remnant of, the earlier tail. A tail was handy for gripping and swinging in trees. A tailbone has no such use in modern man.
- Goose Bumps: Modern humans get goose bumps when they are scared, cold or angry. Many animals also get goose bumps for the same reason. Goose bumps are what makes animal fur and hair stand on end when they are startled, cold or angry. When cold, it is this that creates warmth and insulation between the hairs.
Goose Bumps were handy in the early human evolutionary process when humans wore no clothes and instead had a natural fur coat, but no particular purpose in modern humans.