Last week I made the observation that we were teaching our children as “fact”, three different and opposing views on the origin of man, namely: that God created life on earth in 6 days, that we evolved from simpler life forms over millions of years, and that God used the evolutionary process to evolve us from simpler life forms. This week, we will place Charles Darwin’s proposition as published in “The Origin of Species by means of Natural Selection” in the balance.
Origin of Species was written in 1859, approximately 23 years after Darwin returned from a 5-year exploratory journey around the world. During the expedition he observed how perfectly suited each plant and animal was to its environment, and how interdependent they were.
In his publication, Darwin hypothesized that desired traits can become dominant through selective breeding over many generations. Desired traits can be things like longer or shorter beaks in birds, or larger or smaller sized petals in flowers.
This hypothesis was tested through experiments carried out by Darwin and others where selective breeding of animals and cultivation of plants yielded predictable results. He found that after many generations of breeding, the desired trait became the dominant one. This evidence became the basis of his next hypothesis.
Darwin observed that every organism reproduced at a rate that is unsustainable therefore some of the offspring do not survive. Climate, epidemics, lack of food, and predators are factors that restrict organic populations, however Darwin hypothesised that a process of natural selection mainly determined which offspring survived to reproduce.
Darwin tested this hypothesis through direct observation. He observed that nature did not use the same selection criteria that man used. Man selected offspring for breeding to achieve a physically attractive characteristic over many generations. Nature selected variations or traits that were beneficial to an organisms’ specific environment. Darwin observed that organisms within a species that had beneficial characteristics for that specific environment were dominant in that environment.
In interim summary therefore, Darwin proposed a hypothesis, tested it and found that field observations and experimental test results supported his argument. His argument can therefore be considered a scientific theory. From this rather solid base, Darwin proposed another argument.
Darwin proposed that if man through domestication of animals and plants could achieve such variety over hundreds of years, then nature could achieve greater variety, even to the evolution of new species, over millions of years.
Darwin extrapolated that if variations were still occurring, then the animal and plant forms that we currently see may be transitional forms and may eventually become new species. He then looked back and postulated that all of the life-forms that currently exist have ascended from previous transitional forms. Darwin then carried this extrapolation to its ultimate conclusion by suggesting that we have evolved over millions of generations from very simple life-forms.
In reaching this conclusion, Darwin noted that his proposition required many generations of intermediate forms to be created before the appearance of a new species. He acknowledged that the evidence to support his views was not yet found in the fossil record, but expected that the intermediate forms would be found following more extensive anthropological and geological excavations. He also noted that the discovery of abrupt appearances of species, without the gradual changes of modifications, would be fatal to his views.
It should be noted that the fossil records discovered to date appear to show many species that are the same as they are today, and the fossilized species seem to have appeared abruptly without gradual changes.
During the time that Darwin published his views, scientific debate on the origin of species was dominated by the idea that God separately created each species and that they did not vary. This idea was popular and generally accepted by his society. Darwin proposed an alternative idea that species developed over time due mainly to a process of evolution through natural selection. In accordance with sociological behaviour, he was predictably scorned for challenging ideas generally accepted by his society.
Today, scientific debate on the origin of species is dominated by Darwin’s ideas, which are popular and generally accepted in western society. Scorn is still reserved for those who challenge popular ideas.