Origin of Man
Origin of Man
Scientists believe that the earliest primates were small and nocturnal animals that looked like tree shrews. The development of primates begins with the origin of such animals. Scientists have included two sub-orders (Sub-order) - (1) Sub-order: Strepsirhini and (2) Sub-order: Haplorhini. The members of these two subclasses are respectively called New World Monkeys and Old World Monkeys (North and South America are collectively called the New World. On the other hand, Europe, Asia and Africa are collectively called the Old World). People are in the latter group. It also includes monkeys, Hanuman, owls, gorillas, chimpanzees and orangutans. Haplorhini consists of six families. The tribe to which humans belong is called Family - Hominidae. Members of the primate family are divided into subclasses, tribes, genera and species based on variation in mutual affinity. Members of the family Hominidae are commonly referred to as hominids. Gorillas, chimpanzees, orangutans and humans are hominids. Monkey, Hanuman, Uluk did not live in this tribe. Previously, only humans were included in the Hominidae family, but later studies at the DNA level have determined that these animals are closely related to humans. It does not mean that humans evolved from gorillas, chimpanzees or orangutans. Scientists have not found the root of human origin till date. As a result of the discovery of different fossils over the years, the direction of human origin has changed.
Characteristics of Mammalia in Man (Man as a Mammal)
Like other mammals, humans have the following characteristics:
1. Hair: The human body is covered with light hair; The soles of the feet, the palms of the hands and the face are hairless.
2. Mammary Gland: There is a pair of mammary glands in the thorax (both male and female) which are active in female and inactive in male.
3. Diaphragm: Between the thorax and abdomen is a muscular diaphragm that controls exhalation. 4. Ear: pinna in the outer ear, three small bones in the middle ear and cochlea present in the inner ear.
5. Blood circulatory system: It is advanced and closed in nature; The heart is completely four-chambered and mature red blood cells are devoid of nuclei.
6. Dentition: Heterodont in nature ie the jaw has four types of teeth with distinct characteristics. 7. Brain The brain is well structured and the largest (1300-1450 cubic cm), the cerebral hemisphere.
well developed Unique characteristics of people
From the earliest prosimian primates to the origin of man, all the changing characteristics that humans have acquired are the other characteristics of humans. It is mentioned below.
1. Movement Only humans are able to walk completely on two legs.
2. Sense of smell and vision Since humans are essentially diurnal, their sense of sight has evolved, depending on the sense of smell.
decreased Humans have the ability to see three-dimensional reflections through their eyes (stereoscopic vision). 3. Brain Development: Along with the evolutionary development of vision and the use of limbs came the development of the brain, especially the development of the cerebral cortex. No other mammal has such a mature and large brain. As a result, people have been able to conquer the entire world with the power of thought and intellectual power.
4. Fists Only humans have the ability to make proper fists. The ability to bend the thumb in the opposite direction of other fingers is called opposable grip. Even if Hanuman and apes have this power, it is equally applied to humans. As a result of this, people have been able to apply all modern methods, starting from the use of tools, have become human beings.
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| Figure: Human opposable grip |
5. Increase in life expectancy: Along with the increase in body size due to evolution, the average life expectancy of humans has also increased. Revolutionary developments in medicine have had an impact on human life expectancy.
6. Increase in gestation period: Due to the increase in human gestation period, children are being born in a more mature state.
7. Childhood and pre-adolescence growth: As human childhood and pre-adolescence are longer, the mother-child relationship is closer and the child has more opportunities to learn from the mother.
8. Use of fire: Apart from humans, no other animal in the animal kingdom has learned the use of fire. And this unique feature made Homo sapiens into modern man. Besides, humans are the only animals that consume culinary delicacies.
9. Diverse Dietary Habits: Humans are omnivores. Humans can eat all types of liquid, soft and hard food due to the presence of different types of teeth in the mouth. They get a lot of protein and carbohydrates from a small amount of food with varied cuisine.
10. Development of Social Life: A well-developed social life is one of the key forces behind human evolutionary success and dominance on Earth.
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