Primate Classification and Characteristics
Classification of Primates
Primates belong to the class of mammals and are divided into:
Prosimians
Retain some characteristics of insectivorous mammals. These include the lemurs of Madagascar, lorises, and tarsiers.
Apes
Characterized by exploratory activity and liveliness. They have a complex social life based on sharp colors on the head, buttocks, and fur. Well-developed facial muscles allow them to express their emotions. Their vocal communication includes signs. Examples include New World monkeys and Old World monkeys.
Bipedalism
The ability to maintain body balance upright on the legs is the main feature that distinguishes hominids from other primates. Bipedalism involves changes in hominids:
- The spinal column is S-shaped and convex in the lower back, with the skull vertical.
- The foramen magnum is near the center of the skull base.
- The viscera are suspended from the ribcage, with the diaphragm and abdominal muscles supporting their weight.
- Increased intersection surface of muscle and bones.
- Beveled disposition of the articular surface of the femur in its distal part.
- Forward orientation of the feet due to the intersection of the tibia and foot.
The Quantum Leap
The large size of Homo ergaster and its narrow hip resulted in lifestyle changes:
- Sociability: Promotes walking across the savanna but has a drawback during childbirth. Pups are born with smaller brains, requiring prolonged attention, promoting socialization and learning.
- Improved Tools: Manufactured stone tools, classified as Acheulean industry.
- Competition and Emigration: Resource competition in the savanna led to migration to Asia. While the Acheulean industry developed further in Africa, the Oldowan persisted in Asia.
Anatomical Characteristics of Human Beings
Two specimens were found, including the skull and some postcranial skeletal remains. The skull has a curved wall, high forehead, high cheekbones, absence of brow ridges, small jaw, and the presence of a chin. Compared with other specimens, Homo sapiens has a slimmer figure.
The Lithic Industry
The Aurignacian culture is associated with Homo sapiens. It is characterized by improvements in tool preparation, using direct percussion.
Replacement Hypothesis (Out of Africa)
Defends the appearance of humans in Africa and subsequent dispersion across continents:
- Genetic changes that resulted in modern humans originated in Africa 200,000 years ago.
- 100,000 years ago, Homo sapiens populations dispersed to different continents.
- These populations were replaced by migrating African populations.
Multiregional Hypothesis
Defends the simultaneous emergence of human populations from local hominid populations in different parts of the world. After Homo erectus left Africa, different populations evolved in parallel to the current species through intermediate forms.
Health
Both health and disease depend on several interrelated factors.
Health
Is the result of:
- Genetic Factors: The set of genes an individual receives from their parents. These genes can carry genetic errors.
- Environmental Factors: The environment where an individual lives can contain harmful elements that cause disease.
- Personal Factors: Each individual has characteristics and habits that make them more or less vulnerable to disease.
Healthy Diet
A healthy diet provides adequate amounts of nutrients for the body’s daily energy needs.
Characteristics:
- Should be varied.
- Contain sufficient nutrients according to age, etc.
- Diversify the source of calories.
- Include a hearty breakfast.
- Eat foods rich in fiber.
- Drink 2.5 liters of water a day.
Pasteurization
Heating at 72º for 15-20 seconds and rapid cooling. Typically used for milk. Decreases pathogenic microorganisms without destroying nutrients.
Sterilization
Heating to high temperatures for a few minutes. In UHT (Ultra-High Temperature) processing, it is heated at 145º for 2 seconds. Sterilization destroys all microorganisms and some nutrients.
Canning
Packaging food in an airtight container and immersing it in hot water.
Primates
Placental mammals with a small number of offspring per birth and extended parental care.
Features:
- Ability to stand on hind limbs.
- Prehensile hands and feet with five digits and opposable thumbs.
- Specialized dentition.
- Primates with primitive characteristics have a highly developed sense of smell, but most have a strong sense of sight. Eyes in the front of the head allow for stereoscopic vision.
- The development of sight over smell has resulted in an increase in brain size.
Social Behaviors
The survival and learning of primates depend on the individual, which is favored by the social behavior of the group.