Why can't evolution occur in a single organism?

Answer 1

CharlesDarwin's theory of Natural Selection was a modified form, Darwin's scientific discovery remains the foundation of Biology, as it provides a unifying logical explanation for the diversity of life. Darwin believed in the ideology of the "survival of the fittest" or organism best adapted to the environment. Organisms whose traits best suited their environment survived, and reproduced carrying on those traits, while others of the same species would die out. He believed that organisms would either survive or fail depending on how well they were suited for their environment. Slowly, a change would occur where the organisms, which were once one species, had developed differently into different species. Darwin wrote about his ideas of Natural Selection; and "As, consequently, there is a frequently occurring struggle for existence, it that any being, if it varies enough from others where it is beneficial, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance any selected variety will tend to propagate its new and modified form."

Answer 2

This is mainly due to the fact that an individual organism might be living in a different climate than another of the same organism. Humans can not be observed like this because we are spread through the world so vastly. In 200 years, humans in hot climates will most likely have evolved differently than those in cold climates.

This can also be observed in various sea-life. Some parts of the world might be dumping trash, toxic materials, radioactive materials, and other things into the ocean. This would cause some organisms to adapt to the area and evolve to change their bodily traits as to help them survive the area. Also, toxicities and radioactivity causes mutations in offspring. These "evolutions" are not natural and therefore can not be used to determine the overall evolution of a species.

Evolution was easy to observe and compare from the 1400's to nowadays. We can easily observe this because in that time, there has been more natural change than change induced by controllable variables such as wastes and human involvement.

(NOTE: I am by no means someone experienced in the field of biology, but from what I remember from my high school and college general education and some logical thought process, I can determine this. )

Another answerThis is all very interesting but evolution does not occur in individuals but in a species as a whole over time.