Human Identity, Genetics, and Evolution: A Scientific Perspective
The Problem of Human Biological Nature
The question of human identity leads to questions about our nature and origin. These questions have been raised repeatedly for over 150 years without a satisfactory answer. Today, human identity and origin remain a mystery. Until the nineteenth century, answers were religious and scientific, however, they had remained unchanged since they were based on tradition and dogmatism. Since then, modern science has taken up the solution to these issues, revealing the complexity of human identity. Religious and scientific explanations each have their validity, depending on the framework used to understand them. Moreover, the search for scientific answers to the problem of identity does not negate the search for meaning in human nature. Our attitude towards life and how we relate to the world depends on the answers we find.
Genetic Contribution
Mutations: Hugo de Vries’ Theory
Hugo de Vries was one of the first in 1900 to realize the great importance of Mendel’s laws of inheritance, confirming them with his own experiments. His mutationist theory stated that evolution was not slow and gradual, as Darwin said, but originated in leaps from one species to another individual, without intermediation. He observed two varieties of a plant sprouting new seeds that differed in several characters. This led him to believe that they were two new species born spontaneously without an intermediary because of mutations. According to him, mutations were the cause of the variability of species. Although his explanation was based on the discovery of mutations, it promoted considerable scientific interest about their influence on the evolution of species.
Theory of the Gene: Thomas Hunt
Thomas Hunt, a biologist, received the Nobel Prize for his research on discovering mutations and the function of chromosomes as carriers of the genes of heredity. His work consisted of using X-rays and other energy sources to produce mutations, whose holders could submit new, unimaginable features. Each characteristic became the sign of the corresponding gene mutation, and for the first time, scientists became aware of the genes and their location on chromosomes being responsible for inheritance. The results confirmed compliance with Mendel’s laws of inheritance, failing only when a gene is altered, i.e., mutated.
The Theory of Punctuated Equilibrium
One of the major aspects of Darwin’s theory was the gradual, slow evolution of species, with no big leaps. The synthetic theory collected this aspect, giving rise to intense debate in the scientific community in the last third of the 20th century. Geologists and Niles Eldredge complained that the new synthetic theory claimed Darwin’s gradualism without proof when the fossil record contradicted it. Many organisms remain unchanged for many years and later disappear abruptly, giving way to the sudden appearance of other agencies. With this evidence, the theory of punctuated equilibrium was proposed. This theory suggests that evolution does not change slowly, gradually, and steadily, but as sharp and fast-breaking changes during long periods of immobility. The idea of rapid change was not present in the synthetic theory.