The Homo sapiens
Every human being either man, woman, or child regardless of their color, creed, caste belongs to a single species called Homo sapiens. This is a Latin word that means intelligent or wise man. It reflects the fact that the brain of humans is well developed, much intricate, and large in size.
Humans as Primates
Humans belong to the order Primata of Class Mammalia. Order Primata is divided into three suborders. These are:
This includes lemurs and lorises – small nocturnal mammals only found in Madagascar and East Africa.
This includes tarsiers which are rat-like nocturnal and arboreal mammals only found in Malaya and the Philippines.
This suborder includes monkeys, pes, and man.
The suborder Anthropoidea is further classified into three superfamilies which are following:
This includes New World monkeys of South America. These are brilliantly colored small-sized monkeys with a prehensile tail. Nostrils are widely separated and directed laterally, thus; they are flat-nosed.
Examples of them are spider monkeys, howlers, squirrel monkeys, etc.
This includes old World monkeys of Asia and Africa. These are average, large-sized black or brown color monkeys. They have either short tails or are absent but they do not have a prehensile tail. Nostrils are close together and directed downwards.
Examples of them are Baboons, Mandrills, Langurs, Rhesus monkeys, etc.
This superfamily includes apes such as gibbons, gorillas, orangutans, chimpanzees, and man. This superfamily is subdivided into two families, Pongidae which includes apes, and Homonidae which includes humans. Humans are therefore called “homonids”.
Traits of Primates
Generally, primates are completely hairy arboreal animals with eyes on the front, opposable toes flattened nails instead of claws, collar bone is present, two pectoral mammae with teats, and a variety of teeth.
There are five digits on each hand and foot of primates. The body of a primate is erect or semi-erect. Primates have several modes of locomotion or walking. These can be jumping, leaping or clinging, jumping from branch to branch of trees, walking on two legs, or walking on all four legs.
Primates have highly developed brains with great complexities and exceptional intelligence relative to other animals. The cerebrum in primates is an enlarged part of the brain which receives and synthesizes sensory information.
Apes and Man
Man is more like the chimpanzee and gorilla than the other primates but has enough differences to be placed in a separate family Homonidae. Here are some common and important characters that differentiate man from apes are given.
|They have flattened craniums.
|Their cranium is globular.
|Cranial capacity is 235 to 600 c.c and there is a lack of speech centers.
|Cranial capacity is 1200 to 1500 c.c and thinking and speech centers are well developed.
|They possess flattened noses.
|They have a prominent nose with an elongated tip.
|They possess massive jaws with no chin.
|They possess moderate jaws with chin present.
|Canines project beyond other teeth.
|Canines are small and project little.
|The mouth is protruded forward.
|There is no protrusion as lips are rolled outward.
|The mouth is ‘U’ shaped.
|The mouth is arched.
|Their posture is forward-leaning, with thigh bone curved.
|They have erect posture with long legs.
|There is a massive ridge above the eye.
|Eyebrow ridges are small.
|The spinal column is curved singly.
|They have ‘S’-shaped spinal column with four curves.
|They have big opposable toes.
|They have a non-opposable big toe.
Affinities between Humans and Apes
In spite of these anatomical differences, apes, and humans have a very close affinity with each other. Almost every bone, muscle, internal organ, the blood vessel of the apes are repeated in man. They have similar hormones and enzymes.
They have the same blood grouping such as A, B, and O. There is a menstrual cycle in both. According to DNA and amino acids research and analysis, Humans and Chimpanzees share 99% of their genes.
The biochemical similarities among gorillas, chimpanzee,s, and humans are such that many systematists believe all three should be placed in the same family or perhaps the same genus. However, because of anatomical differences, they have been traditionally placed in different families.
Evolutionary Development of Man from Apes
The following factors seem to be of prime importance in determining the evolutionary development of man from ape-like ancestors.
- Growth and development of brain
- Perfection of erect posture
- Slowing or prenatal development
- Growth of human populations
- High brain functioning
Man is physically very weak and inferior to large animals but he excels all because of his intelligence. Man’s ability to think, communicate and tool-making enabled him to exploit and dominate his environment.
- Divergence from other primates
Main diverged from other primates which are either tree dwellers or ground living that run on four legs. The upright posture and bipedal locomotion in man have freed his hands for offense, defence, and holding objects.
- Parental care
A gorilla matures at the age of 10 whereas a man at the age of 18. This means that human beings live a long time under parental care than other primates and this leads to the perfection of family life.
- Growth of Human populations
Finally, the growth of human populations is of utmost importance, particularly past few thousand years. From family groups to tribes and finally nations. This trend in human evolution is of great importance in the modern world and the future is dependent on the social behavior of man.