Nancy Sherer presents a primer...
EVOLUTION IS THE FACT
HOW IT WORKS IS THE THEORY
Because our schools do not have adequate science teachers who understand evolution, I am listing the basic facts. I hope this will lead to a more intelligent conversation on the issue. Following are the most common misunderstandings about the subject.
Evolution is a fact, not a theory. Scientists generally agree that Darwin's Theory of Evolution is the correct explanation of how life on earth developed. Even if other scientists come up with different theories about how evolution works, evolution itself remains a fact. Let's consider this in light of another scientific fact - gravity. Gravity is a fact. How gravity works is a theory. Current theories about gravity might be disproved, but gravity remains a fact.
Some terms have been attached to Darwins theory although common understanding of them is incorrect. Survival of the fittest does not mean survival of the strongest, smartest, fastest, meanest, or best camouflaged. Survival of the fittest means that an organism that is best adapted to its ecological niche will probably leave more offspring than less fit individuals. Consider the garden slug or the cockroach as great examples of fitness for survival.
Natural selection is Darwins theory of how the environment works on species. Although genetics were not understood at the time, later science confirmed Darwins logic was reasonable. Individuals that are most successfully reproducing viable offspring form the gene pool of a species. Environmental forces determine which individuals survive. Insects tend to be successful not just because of the number of offspring they produce, but because this genetic trait is favorable to the insects' particular environmental niche. Insects that produce a lot of offspring survive best.
A breeding pair of elephants, Darwin reasoned, produce a population of 19 million elephants over 750 years, yet the number of elephants each year remains more constant. Natural constraints limit the number of elephants. Elephants that reproduce by putting enormous time and resources into a small number of offspring have made them the slowest breeders on earth.
The Theory of Natural Selection indicates that both insects and elephants are fit for their ecological niche because their respective methods of reproduction are successful. As science discovers more about chemistry, geology, and biology, the evidence for Darwins theory of evolution grows more unimpeachable.
Life on earth is a chemical reaction which not only has some control over the rate of its reaction, but is also in many ways, aware of itself and able to respond to its surroundings. Scientists at Cornell University recreated the circumstances that they deduce existed on earth over a billion years ago in an experiment to see if they could create life. Their success was both delightful and alarming. The chemical reaction of life is apparently much easier and quicker to accomplish than was previously thought. And of course, realizing the dangers of creating a second breed of life, the scientists discontinued the experiment.
It remains a fact that all life today began more than 3.5 billion years ago with a basic chemical reaction. Since then, that reaction slowly grew during the succeeding countless generations into the hundreds of thousands of plants and animals that fill the ecological niches. Chemistry and physics changed the landscape through volcanic upheaval to develop a variety of habitats in the cooling process.
Evolution continues on earth today even as we debate the issue.