In the field of molecular anthropology, the true meaning of genetic diversity has not been fully understood for a long time. A high level of genetic diversity is usually interpreted or assumed to mean a long evolution time. According to this logical system (molecular clock neutrality theory), the San people of southern Africa, who have the highest genetic diversity, the lowest intelligence, and the lowest level of civilization among humans, are considered to be human ancestors, leading to the theory that modern humans came from Africa.
and Huang Shi, professor of at Central South University, gave another interpretation. The genetic diversity upper limit theory he established believes that genetic diversity has an upper limit, which is inversely proportional to species complexity or mental function. This inverse relationship exists almost perfectly in real species: the higher the species, the lower its genetic diversity, and humans have the lowest genetic diversity. According to this explanation, the highest genetic diversity of the African San people is actually not related to evolutionary time, but to their minds. The origin of modern humans is actually not in southern Africa, but in East Asia.
In order to verify which theory is correct, Huangshi team researcher Wang Mingrui conducted the most convincing research topic under current conditions. The research paper was recently published in the Journal of Human Genetics (Journal of the Japanese Society of Human Genetics, a magazine of "natural"). The study analyzed genotype and phenotypic data from more than 400,000 British people, calculated multiple indicators of genetic diversity for each individual, and examined which traits these indicators were associated with using linear regression analysis that excluded confounding factors. Among the 17 traits examined, only education level, a trait that is highly correlated with IQ, has the most robust and significant relationship with genetic diversity, and it is negatively correlated. This correlation is likely to be causal because only genes expressed in the brain, not genes not expressed in the brain, show correlation. This conclusion basically rules out the interference of confounding factors, because the correlation of non-synonymous variants is significantly higher than the correlation of synonymous variants or intronic variants.
Genetic diversity comes from random mutations, which reflects the degree of randomness within an individual organism. Consciousness or mind is the only force that can resist suppressing the random movement of matter. Mind and matter or randomness are in opposition to each other. If one is weak, the other is strong. High genetic diversity or randomness must mean a low level of mental function, and vice versa. Poor mental function is subject to natural selection pressure, so genetic diversity is subject to natural selection, rather than being primarily time-related and not subject to natural selection as the neutral theory of molecular clocks suggests.
This new paper by the Huangshi team demonstrates that genetic diversity is a new genetic factor in mental function, challenging the out-of-Africa theory. The highest genetic diversity of the San people in southern Africa is the result of natural selection and has nothing to do with evolutionary time or human ancestors. It also provides strong evidence for the upper limit theory of genetic diversity and the theory that modern humans originated from East Asia based on this theory.
Xiaoxiang Morning News reporter Li Jiamei
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