Darwin and the Theory of Natural Selection
The principal merit of Darwin's theory, in addition to the many evidence that he provided to it, is the discovery of the mechanism that governs the entire evolutionary process of species: the natural selection.
- Firstly, when environmental resources become scarce, an inevitable competition occurs and, consequently, the struggle for survival begins in which most individuals die.
- Secondly, it is also obvious that individuals of the same species have different features or characteristics that appear randomly and make individuals different from each other.
- Third, these characteristics make some individuals more advantaged than others. Those whose characteristics are favorable to the demands of the environment are more likely to reproduce and survive than those with less favorable characteristics. Therefore, only the fittest individuals survive.
- Finally, since the favorable characteristics are transmitted by inheritance, they become increasingly widespread, while unfavorable characteristics become rare until they finally disappear. The result will be a new different species, as all those individuals present those favorable characteristics.
Mendel and the Laws of Genetic Inheritance
Mendel is considered the father of Genetics because of his research on the mechanisms of heredity. His work was to observe the crossing of thousands of peas with distinct characteristics of color and texture, demonstrating that the common opinion that affirmed the characteristics were transmitted from parents to offspring mixed was false.
- Law of Segregation: During gamete formation, the alleles for each gene segregate from each other so that each gamete carries only one allele for each gene.
- Law of Independent Assortment: Genes for different traits can segregate independently during the formation of gametes.
- Law of Dominance: Some alleles are dominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.
The Role of Aggression and Violence in the Evolution of Species
Konrad Lorenz expressed concern about the situation of mankind, which seemed to be headed toward the possibility of its self-destruction. Lorenz focused on studying the role of aggression among members of the same species. In a first approximation, Lorenz stated that aggression among members of the same species fulfills fundamental functions in their conservation. In the case of humans, from aggression arises the possibility of coexistence among human beings through the emergence of morality. The human being has developed artificial inhibitory mechanisms against violence and aggression between individuals of his same species to counter the absence of a natural mechanism. We have developed a series of norms and moral imperatives (and eventually also legal laws) that have allowed us to "tame" our insatiable instinct of violence.