What Is Evolution?
Biological evolution refers to the changes that occur in a population over time. These changes are produced at the genetic level as organisms' genes mutate and/or recombine in different ways during reproduction and are passed on to future generations. Sometimes, individuals inherit new characteristics that give them survival and reproductive advantages in their local environments. These characteristics tend to increase in occurrence in the population, while those that are harmful decrease in frequency. This process of making more of the best and getting rid of the worst is known as "natural selection" or "survival of the fittest". Some people think that any change in an organisms' body or genetic makeup is evolution. However, this is not true. Non-genetic changes that occur during an organism's life span, for example increases in muscle tissue due to exercise cannot be passed on to the next generation and are not examples of evolution.
Are all species related?
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