User talk:Spudking

Evolutionary Theory had been hinted at long before Charles Darwin, but it was Darwin that nailed it down... In his "The Origin of Species" masterwork that integrated both generalities and specifics together through his observations, that lent the needed scientific credibility, to the then hypothesis that has now become an accepted working scientific theory, of our and every other species Lineage or descent from ancestry (common ancestors).

There is little dispute today within the scientific community of the soundness of this theory. Many scientists do disagree on some aspects of the theory but the theory in general is accepted.

Evolution can be summed up in simple terms in the following way: Genes mutate, individual animals are selected through natural selection and populations evolve.

Gene mutation is a process of chance, but this does not mean that evolution is a theory of (just) chance as often implied. The theory involves both chance and selection over time.

Chance mutations in the genetic makeup of individuals of a species do occur... These genetic mutations can either be neutral, harmful or beneficial... This shouldn't be taken to mean that individuals within a species spontaneously mutate like a frog turning into a prince. Mutations are hereditary errors in the genetic code carried by certain individuals. If a male and a female mate and carry the correct combination of genetic information for cystic fibrosis for example then the combination of the genetic coding is passed to descendent's and that would be the cause of that particular chance mutation in a common descendant.

These chance genetic mutations are caused by an error in the coded genetic information of a strand of DNA.

If the change is neutral this means it will have no effect on the species within the gene pool; if the change is harmful then it's survivability prospects may diminish or the opposite case in a beneficial mutation.

If evolutionary theory relied on chance alone then the theory would fall down. It is a trick often used by creationists to attack evolution on the premise that it is a theory of chance and from here they argue that a theory based on chance is a poor theory because of lack of statistical probability.

But chance is only a small but necessary aspect of evolution.

A most important aspect of evolution to understand is natural selection. Natural selection simply means that a natural element of a species such as wing diameter in birds or camouflage coloring in butterflies is favored (selected) over a less efficient aspect of itself with regard to its success in its environment and is thus a more efficient survival mechanism and is thus carried on into the genes of descendants.

Here is an example of observed evolution and how evolution works:

The English moth, Biston betularia, has two color morphs light and dark H. B. D. Kettlewell found that dark moths constituted less than 2% of the population prior to 1848. In Manchester England the frequency of the Dark Moth increased over the light moth. By the year 1989 the Dark Moth increased in ratio over the light moth and increased to reach 95% of the population. Similar events were recorded in other cities.

Why did this happen?

The answer is industrialization. As the city industrialized this left soot deposits which blackened the surrounding environment. The Dark moths were thereby better camouflaged against a sooty background and the light moths by comparison were conspicuous in the environment and were picked off by birds.

Because there were more dark moths they thus mated with moths of the same kind and thus the genes for Dark Moths "swamped" the gene pool and the light moths genes got "pushed out" of the gene pool.