Up to 1960’s, the mainstream evolutionists only believed that almost speciation requires “natural selection” and Japan’s geneticist Motoo Kimura launched a strong challenge to the idea. Kimura said that at the molecular level, most of the variation within a species does not come due to natural selection, but from neutral or close to neutral mutations caused by random genetic drift, which is neutral from the perspective of adaptation. This process is also known as a random genetic drift (Kimura, 1968).
The genetic drift theory is a non-Darwinian one. Initially, the theory met a strong resistance from the mainstreamers. In the 1980s, most of the evolutionary geneticists including Darwinian theorists have accepted the theory as one of the mechanisms of the evolution.
Kimura Motoo’s theory was directly related to the advancement in molecular biology. In 1953, James Watson and Fredrick Click discovered the double helix structure of DNA, which marked the beginning of the molecular biology. In year 1955, F. Sanger completed the amino acid sequence of insulin, which indicated pathway of genetic information from DNA to proteins. Protein is made from 20 types of amino acids, the sequence of amino acids determines nature of proteins.
DNA is a long-chain polymer with its basic units called nucleotides. There are four different kinds of nucleotides. Nucleotides are arranged into a DNA long chain that forms the genetic code. According to the DNA sequences, mRNA is synthesized. the mRNA is a template for the sequence of amino acids.
Each of three adjacent nucleotides in the mRNA works as a group, called codon. During synthesis of protein, the codon will determine the amino acid. Each site in mRNA may have four possible nucleotides. The three sites will have 64 (4x4x4) probabilities which could code for 64 codons. However, only 20 amino acids correspond to the 64 codons. This means that some amino acids have two or more codons, such as the phenylalanine its codons are UUU and UUC.
Nucleotide in a DNA chain mutates at a rate about once every 1 million or 1 billion. If a mutation occurs in DNA molecules, mRNA would change accordingly, alternation in mRMA codon might still code for same amino acid, the resulted protein did not change, this is the interpretation of the genetic drift at the molecular level. There is no change on protein structure and function in the genetic drift, therefore no effect on survival. Neutral mutations can be preserved naturally, which frequency depends on opportunity.
Contradiction between the assumptions and inference
When ones do not understand reason for a particular phenomenon, assumptions are often necessary, based on which hypothetical reasoning is made. Assumption and inference must be consistent. If inference does not match the reality. Initial assumptions should be modified or discarded.
Take SARS for an example, on November 16, 2002 there was the first outbreak of the disease in Shunde, Guangdong province, China, In the end of December 2002, Guangdong’s people turned up to talk about a deadly disease, a disease where persons were infected in hospitals and clinics, and died. Nobody knew the cause of the disease. There were different thoughts about the cause, it was thought that the disease was caused by a known bacteria or unknown bacteria, or a plasma, or a viral infection. Local doctors went to treat with the antibiotics and found them ineffective, and the culture results showed no bacterial growth, thus they concluded that the disease not caused as a bacterial infection. Here, the assumption is bacterial infection, the inference is utilization of antibiotics, the reality is antibiotics useless. In the case, the assumption is consistent with the inference. This is the basic logic of thinking, and does not require PhD.
Population genetics is an important branch of the biological evolution, on which the so-called “modern synthesis” is built, many mainstream evolutionists, including its founder T. Dobzhansky, are the experts in population genetics. How do they explain the formation of a new species? They propose that mutations are accidental on individual that could extend to groups by either natural selection or genetic drift to a point it becomes fixed in the population, which is a new species. What is fixed? By the definition, if mutation entire group or 100% population carry the mutation.
This theory has two basic questions first: if a new mutation arises at an individual that could extend into a group, the individual must mate with others with healthy offspring, the individual and its mates have to belong to the same species.
The assumption is that individual with the mutations can mate other individuals and have children, the inference should be that they must belong to the same species.
However, the theory of genetic drift has incongruous assumption and inference. What the theory says that initially the mutated individual the same species with other individuals, after awhile they are not the same species any more. If the theory were correct, the next question are: how can it happen? Does the change happen one by one, or altogether. Who orders the change? Only the mainstreamers can do is to ask you apply wide imaginations.
This second question would be which organisms has a gene with 100% same in the world? Like height, weight, eye color, no individual in any group is exactly same. As far as a human with about 23,000 genes goes, there is no gene that is 100% same or close to same. Assume that mutation of a gene can be 100% by extending to the entire group itself is against basic knowledge of molecular genetics; it is sad that see the mistake made by the world’s leading population geneticist.
Kimura, M. (1968). “Evolutionary rate at the molecular level.” Nature 217(5129): 624-626.