The Theory of Evolution

Darwin's Theory of Evolution is the widely held notion that all life is related and has descended from a common ancestor: the birds and the bananas, the fishes and the flowers -- all related. Darwin's general theory presumes the development of life from non-life and stresses a purely naturalistic (undirected) "descent with modification". That is, complex creatures evolve from more simplistic ancestors naturally over time.

In a nutshell, as random genetic mutations occur within an organism's genetic code, the beneficial mutations are preserved because they aid survival -- a process known as "natural selection." These beneficial mutations are passed on to the next generation. Over time, beneficial mutations accumulate and the result is an entirely different organism (not just a variation of the original, but an entirely different creature).

The Mechanisms for Evolution

Mechanism # 1 - Mutations

Textbook Quotes:

“Any change in the DNA sequence is called a mutation. Mutations can be caused by errors in replication, transcription, cell division, or by external agents.” (ex: radiation) Prentice Hall Biology - 2006, Pg. 296

“The cell processes that copy genetic material and pass it from one generation to the next are usually accurate.” Prentice Hall Biology – 2006, p. 301

“The mutation may produce a new trait or it may result in a protein that does not work correctly, resulting in structural or functional problems in cells and in the organism.” Prentice Hall Biology - 2006, Pg. 296

“Sometimes, the mutation results in a protein that is nonfunctional, and the embryo may not survive.”

Prentice Hall Biology - 2006, Pg. 296

“In some rare cases, a gene mutation may have positive effects. An organism may receive a mutation that makes it faster or stronger; such a mutation may help an organism – and its offspring – better survive in its environment.”

Prentice Hall Biology - 2006, Pg. 296

“Mutations are the ultimate source of genetic diversity in the living world …”

Prentice Hall Biology

2006, pg 243

“Any agent that can cause a change in DNA is called a mutagen.”

Prentice Hall Biology - 2006, Pg. 301

“Forms of radiation, such as X rays, cosmic rays, ultraviolet light, and nuclear radiation, are dangerous mutagens because the energy they contain can damage or break apart DNA.”

Prentice Hall Biology - 2006, Pg. 301

Mechanisms are in place to correct changes in DNA:

“Much like a book editor, enzymes proofread the DNA and replace incorrect nucleotides with correct nucleotides.”

Prentice Hall Biology - 2006, Pg. 301

“In spite of these mechanisms, however, changes in the DNA occasionally do occur.”

Prentice Hall Biology – 2006, p. 301

Scientists who hold to a naturalistic view of origins interpret those mechanisms as being a product of a change that proved to be beneficial. Some circular reasoning seems to be involved and this part of the process gets a bit confusing at times.

Scientists who hold to a supernatural view of origins interpret those mechanisms which protect DNA from changing as proof those protective mechanisms were purposefully formed. The question is asked: “Wouldn’t the repair mechanisms that prevent change, also be likely to repair any possible beneficial change?”

How often exactly do beneficial mutations occur? 

Luigi Cavalli-Sforza, head of the international Human Genome Diversity Project, in “Genes, Peoples, and Languages”, on pg. 176 said: “Genetic mutations are spontaneous, chance changes, which are rarely beneficial, and more often have no effect, or a deleterious one.”

Dr. Lee Spetner (Ph.D. Physics – MIT, taught information and communications at Johns Hopkins University) said: “But in all the reading I’ve done in the life-sciences literature, I’ve never found a mutation that added information… All point mutations that have been studied on the molecular level turn out to reduce the genetic information and not increase it.”

Ray Bohlin, (Ph.D. in molecular and cell biology) said: “We see the apparent inability of mutations truly to contribute to the origin of new structures. The theory of gene duplication in its present form is unable to account for the origin of new genetic information."

Facts About Mutations:

1. Mutations are rare.
2. Mechanisms are in place to correct changes in DNA.
3. Beneficial mutations are extremely rare.
4. Mutations do not produce new genetic information.
5. Mutations result in a net loss of genetic information over time, not a net gain.

“Each cell has a number of pathways through which enzymes recognize and repair errors in DNA. Because DNA can be damaged or mutated in many ways, DNA repair is an important process by which the body protects itself from disease.

A very small percentage of all mutations actually have a positive effect.

Human body cells form two broad categories: germ cells and somatic cells. ... A somatic cell mutation in an organism is passed on to daughter cells in the organism. But this type of mutation doesn't affect future generations because only genes carried by sperm or egg will affect offspring.”

US National Library of Medicine

Mechanism # 2 - Gene Flow

Gene flow—also called migration—is any movement of genes from one population to another. Gene flow includes lots of different kinds of events, such as pollen being blown to a new destination or people moving to new cities or countries. If genes are carried to a population where those genes previously did not exist, gene flow can be a very important source of genetic variation.

Mechanism # 3 - Genetic Drift

Genetic drift pertains to the process of change in the frequency of an allele (gene variant) in a population over time. The change is caused by chance or random events (e.g. a disastrous event in a habitat) rather than by natural selection.

Mechanism # 4 - Natural Selection

Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce.  "Survival of the Fittest."

They did an experiment in which through radiation they produced 80,000 generations of fruit fly mutations. They hoped to produce millions of years of mutations in a short time, and perhaps to see evidence of evolution. The ones they produced were all worse off than the previous ones.

They concluded fruit flies must have evolved as far as they could go.

Something you should know about Natural Selection:
Natural selection has no consciousness, intelligence, foresight or creative capability.  It is at the mercy of random processes because it can only select what random mutational change can create.

Textbook Quote:

“Natural selection can act only on those biologic properties that already exist; it cannot create properties in order to meet adaptational needs.” Parasitology, 6th ed. Lea & Febiger, p. 516.

“Natural selection may have a stabilizing effect, but it does not promote speciation. It is not a creative force as many people have suggested.”

Daniel Brooks “A downward Slope to Greater Diversity,” Science, Vol. 217, 24 September 1982, p. 1240

Supernaturalist scientists ask: “How many harmful mutations will accumulate before enough beneficial mutations do, to actually improve a life form? Will the life form go extinct before it gets a chance to improve?”  “The more mutations you get in a population group, wouldn’t that lesson the likelihood of survival?” 

Naturalist scientists respond with: “The harmful mutational changes are not passed on to future generations, only those that are beneficial survive.”