Evolution and the Origin of Humans: Darwin’s Insights
Evolution and Natural Selection
According to Darwin, in nature, there is a continuing struggle between individuals. Those with favorable changes are chosen by natural selection and, therefore, are the ones that survive.
Neutralists (Neo-Darwinism)
Neutralists attribute neutral genetic variability mainly to chance, i.e., mutations. Most argue that they are neutral with respect to natural selection. Only in some cases, mutations are favorable and are chosen by natural selection. Also, in the process of evolution, other factors influence, such as the longevity of individuals and the number of individuals affected by the change.
Laws of Evolution
All evolutionary theories take for granted trends in the evolutionary mechanism that is summarized in three laws:
- Law of diversification
- Law of the irreversibility of the changes
- Orthogenesis Act (the species tends to complexity in the structures, both biological and social)
The Origin of Man
Since the second half of the 19th century, Thomas Huxley, Charles Darwin, and Ernst Haeckel argued that the human evolved from species similar to apes. The human being is part of the family of pongids (gibbons, orangutans, chimpanzees, gorillas, etc.). Hominids simultaneously belong to the superfamily of apes. Of the hominids, the only living species is Homo sapiens.
The Australopithecines
The Australopithecines lived in the jungle about a million years ago. They had a cranial capacity of about 500 cm3, presented an ape-like face and small stature, and were already bipedal.
Homo Habilis
Homo habilis came to be contemporary with Australopithecus. They had a slightly convex face, smaller teeth, and a brain size of around 700 cm3. They were characterized by toolmaking, prompting a primitive social organization. They communicated by guttural sounds and used fire sporadically.
Evolution and Natural Selection
According to Darwin, in nature, there is a continuing struggle between individuals. Those with favorable changes are chosen by natural selection and, therefore, are the ones that survive.
Neutralists (Neo-Darwinism)
Neutralists attribute neutral genetic variability mainly to chance, i.e., mutations. Most argue that they are neutral with respect to natural selection. Only in some cases, mutations are favorable and are chosen by natural selection. Also, in the process of evolution, other factors influence, such as the longevity of individuals and the number of individuals affected by the change.
Laws of Evolution
All evolutionary theories take for granted trends in the evolutionary mechanism that is summarized in three laws:
- Law of diversification
- Law of the irreversibility of the changes
- Orthogenesis Act (the species tends to complexity in the structures, both biological and social)
The Origin of Man
Since the second half of the 19th century, Thomas Huxley, Charles Darwin, and Ernst Haeckel argued that the human evolved from species similar to apes. The human being is part of the family of pongids (gibbons, orangutans, chimpanzees, gorillas, etc.). Hominids simultaneously belong to the superfamily of apes. Of the hominids, the only living species is Homo sapiens.
The Australopithecines
The Australopithecines lived in the jungle about a million years ago. They had a cranial capacity of about 500 cm3, presented an ape-like face and small stature, and were already bipedal.
Homo Habilis
Homo habilis came to be contemporary with Australopithecus. They had a slightly convex face, smaller teeth, and a brain size of around 700 cm3. They were characterized by toolmaking, prompting a primitive social organization. They communicated by guttural sounds and used fire sporadically.