Let’s return now to the topic of natural selection. Natural selection is true, but new species do not develop through natural selection. What happens is that portions of a population which already have characteristics which provide a survival advantage will be able to survive better when there is environmental pressure. These characteristics or features are not new and not the results of natural selection. Life forms already have a variety of characteristics which are present through genetic variation. DNA has so much information that only a portion is expressed in any one individual. The expression of a portion of DNA in one individual will produce a characteristic which is different than the expression of another portion of the DNA in another individual. This results in a variety of characteristics within a population of a species, where some of these characteristics will be favored. Natural selection selects among a variety of features already present, it does not produce new features. This is the difference. This will become clear with an example.
Consider the finches that Darwin observed when he went to the Galapagos Islands. Darwin was an excellent observationist. He observed a tremendous variety of life forms and commented specifically on the variety of beaks that the population of finches had on these islands. He took extensive notes and made numerous drawings. He reasoned that the different beaks he saw on the birds would make some birds better able to survive in certain conditions. The finches had many different shapes to their beaks, some of the finches had short fat beaks and others long and narrow. He thought correctly that the finches with long narrow beaks would be better able to get seeds from nuts in times of drought. He presented natural selection as a process that would select out the finches with long beaks and over time a greater percentage of the finch population would have these beaks as others would die from starvation.
There is an intellectual error here. Some of the finches already had long narrow beaks before the drought. The long narrow beaks were not the result of random chance mistakes of reproduction (mutations) that were a new feature, this feature was already in the DNA of the finches coding for long narrow beaks. The birds that expressed this gene and had long beaks had a survival advantage and over time there became more birds with long beaks and fewer birds with short beaks.
Another example is the moths in Britain. Some moths have grey wings called Peppered Moths and others have bright colored wings. After the industrial revolution there was enough pollution and smoke that the bark on trees became darker. The peppered moths were then harder to see by their predators which are birds and more of the bright colored moths were eaten and less of the Peppered Moths. Over time there was a change in the population of moths and there were more moths with dark wings. This is natural selection. A feature like the length of beaks on finches or the color of wings on moths gives them a survival advantage in their environmental habitat. However, there are no new features that ‘evolved.’ Some of the finches already had long beaks and some of the moths already had dark wings.
There will be a change over time in the characteristics of a population of a species as favorable features are selected by the environment, but these characteristics were already present in the species, they were not created new by natural selection.
It is a logical error to conclude that since natural selection is true, then evolution is true. Natural selection is true and agreed upon by all. However, evolution is not proven and not agreed upon.