Human Evolution: From Hominids to Homo Sapiens

Posted on Dec 7, 2024 in Psychology and Sociology

**Hominization: The Evolutionary Journey to Humanity**

Biological anthropology defines hominization as a process of humanization. Changes promoted by the evolution of animals have allowed the emergence of the human species. The process began with the appearance of:

  • Bipedalism: A factor that differentiated hominids from other species.
  • Encephalization: A determinant of the occurrence of the genus Homo.

Hominids

The first phase is defined by the appearance of the family of hominids. The African continent is the cradle of humanity. The first hominids were Australopithecus afarensis, which lived about 4.5 million years ago.

Genus Homo

Brain size is the factor that distinguishes the Homo genus of hominids. It enabled us to appreciate the different species within the genus Homo. A hominid belongs to Homo when its cranial capacity is greater than 600 cm3.

Homo habilis

Cranial capacity greater than 600 cm3. Habilis is characterized by the appearance of the opposable thumb in his hands. It is the first toolmaker. Its remains have an age of between 1.9 and 1.6 million years. Oldowan culture.

Homo ergaster and Homo erectus

Ergaster: A species that diversified from Homo habilis. It appeared about 2 million years ago. Some left Africa and spread through Europe and Asia (Homo erectus), and some of the others evolved into Homo antecessor.

Erectus: Remains dated between 1 million and 100,000 years ago. High degree of efficiency and refinement of cutting tools and axes. Acheulean culture.

Characteristics of Homo ergaster and Homo erectus

  1. Need for parenting and newborn care. This makes the relationship established beyond instincts.
  2. A high degree of cooperation required for the hunting of animals, which suggests a development of social organization.
  3. Effectiveness of weapons and tools to incorporate proteins necessary for brain development.
  4. Using fire, decisive in the process of humanization. Its mastery improves the quality of life.

Homo antecessor

Species discovered between 1994 and 1997 in the Sierra de Atapuerca. It emerged in Africa more than 1 million years ago from Homo ergaster. Their presence in Atapuerca dates back 800,000 years. It gave rise to two lines of evolution:

  • Homo heidelbergensis: 500,000 years ago. It derived from the species Homo neanderthalensis.
  • Homo rhodesiensis: the last 200,000 years. It led to the species Homo sapiens.

Homo neanderthalensis

Appeared 300,000 years ago. Burly and equipped with a cranial volume greater than ours. They came to the consciousness of death. Mousterian culture. They had the capacity for symbolic representation and language. It became extinct 30,000 years ago, during the last glaciation. It shared territory with Homo sapiens.

Homo sapiens

It comes from Homo rhodesiensis. According to studies of mitochondrial DNA, it is descended from a small community that lived in Africa 200,000 years ago. Characterized by:

  1. Cranial capacity of 1450 cm3, up from the current human average.
  2. Anatomically equal to us.
  3. Produced fire at will.
  4. Equipped with logical reasoning.
  5. Has symbolic capacity.

Expansion began slowly but steadily. It arrived in Europe 40,000 years ago and shared territory with Neanderthals for 10,000 years. The explanation for their evolutionary success:

  1. Its processing capacity enabled it to adapt the environment to its needs thanks to increasingly effective tools.
  2. The organizational capacity of articulate speech enabled it to create corporate structures based on cooperation.
  3. Its capacity for symbolic representation enabled it to express feelings and emotions.

Nature, Culture, and the Human Being

Humans are animals that are born with a nature and, throughout their lives, acquire a culture.

  • Nature: Genetic determinants that an individual has from birth. It encompasses all those factors and conditions that we inherit.
  • Culture: Anything that humans learn or acquire, such as social customs, beliefs, knowledge, and so on.

Human Nature

Biological nature of man: a set of abilities and characteristics that define human beings and are encoded in their genome. The genetic characteristics are shared by all members of a species, and there are individual differences.

  1. All individuals of a species share a set of characters by which some species are distinguished from others. Example: The human species.
  2. With sexual reproduction, the characters of the descendants come from the male and female. Genetic factors are what make us all different.

Genetics and Humans

Genes also influence aspects of behavior.

  • Same genes, different environments: Twins separated at birth show similar behavior, but they have never been in contact.
  • Different genes, same environment: Adopted children educated in the same family as their biological parents have similarities, despite never having been in contact.

Genetic Determinism

According to genetic determinism, both physical and behavioral aspects are determined solely by genes. Today, few scientists believe this.

Medicine and Genetic Engineering

Genetic Engineering is a biotechnology that involves the handling and transfer of DNA from one organism to another, enabling the creation of new species, correcting genetic defects, and manufacturing many compounds. Although there are warnings of the danger, the benefits are innumerable. Thinkers argue against the claim to improve the human genome using artificial techniques (eugenics), which was applied by the Nazis. Sloterdijk defended himself, saying that eugenics is to improve conditions that will create the next generation, while the Nazis took advantage of it to eliminate the sick.

Breeds

They are groups of individuals who show greater genetic similarity than they do with individuals of other groups. The notion is based on the idea that individuals are physically different because they are adapted to very different climates and environments (a problematic concept to apply to humans). Natural selection has favored those traits beneficial to environmental adaptation. In the 19th century, differences among different human groups, such as skin color, led researchers to consider the subdivision of human races. Most scientists reject this.

Racism

It is to assume that there are superior and inferior human races, depending on the possession of attributes that are particularly important. This ranking is used by racists as an excuse to discriminate against the inferior race. Nazism is one of the highest expressions of the use of biological concepts without any scientific basis to justify their crimes.

Culture

Includes all the knowledge, beliefs, customs, and human inventions. Cultural anthropology studies what culture is. The notion of culture includes:

  1. Tools, techniques, and technological works that man has devised.
  2. Knowledge, beliefs, and opinions, products of human creativity.
  3. Social customs.

Culture as Information

In cultural evolution, it means adapting to human needs. Culture varies from one group to another. Culture and customs information is transmitted from one individual to another and from one generation to another. Spoken language allowed the transmission of ideas from one generation to another, but some could be missed over time. Writing solved this problem and brought about a revolution. Humans are cultural animals thanks to:

  • Invention: Culture consists of tools and practices that have been invented.
  • Transmission: Thanks to its capabilities and language, information can pass from one person to another and from one generation to another.
  • Learning: A person is capable of acquiring and internalizing behaviors and habits not received genetically.

There are two extreme divisions of cultural diversity to be avoided:

  • Ethnocentrism: It consists of judging foreign cultures with their own cultural standards. It leads us to use our ideas and practices as the sole criterion to assess and judge others. It can hide racist attitudes.
  • Cultural relativism: It consists in considering that we have to accept any custom or practice if it is part of a tradition. It is inadmissible if it violates dignity or is used to justify persecution or death.