Natural Selection is how species evolve to fit their
environment. Another way of putting it is "survival of the fittest."
Those individuals best suited to the local environment leave the
most offspring, transmitting their genes in the process. This
natural selection results in adaptation, the accumulation of the
genetic variations that are favored by the environment.
Many Greek scientists thought about natural selection and the origin of life. Anaximander believed that marine life was the first life on Earth and that changes happened to animals when they moved to dry land. Empedocles had the idea
of chance combinations of organs arising and dying out because
of their lack of adaptation. Aristotle, a Greek philosopher who
contributed many works in the sciences, believed that there is
purpose in the workings of nature, and mistakes are also made.
He thought that nature working so perfectly is a necessity. Aristotle
believed that nature is everything in the environment, like the
sky rains, and the plants grow from the sun. Aristotle's theory
fits very well with natural selection. Natural selection makes
it necessary that animals and nature fit perfectly. If they didn't,
then that specific organism would die out, weeding out the characteristics
that were unfit for that environment. That same organism's species might evolve
over time and acquire adaptations suitable for the environment,
so that newly evolved species can survive and flourish with offspring.
Another scientist, Lucretius, who lived about 50 AD in Rome, believed that evolution was based on chance combinations; heredity and sexual reproduction entered only after earth itself had developed. Then with the organism
developing characteristics that might make for survival in the
environment, the organisms that don't have favorable characteristics
are incapable of survival and disappear.
These ideas from Greek scientists are all theories,
of course, but the fossil evidence suggests that species evolved
over time.
Click below for the next topic: