Homo sapiens is the most known species over 7 million years of evolution on earth. The fossil record, along with studies of human and ape DNA, indicates that the evolution of man, modern humans and chimpanzees evolved from a common hominoid ancestor that diverged approximately \(7-8\) million years ago.

Evolution is hypothesised to have started from simpler forms in the oceans, from simple to more complex life. Fifty-five million years ago, the first primates appeared on earth. Humans’ earliest ancestors are said to have originated in Africa before migrating to Europe, Asia, and the rest of the world. So let us read the article to know more about the origin and evolution of man.

What is the Evolution of Man?

Evolution is the slow and gradual process of living organisms evolving from earlier, more simple organisms. Evolution is hypothesised to have started in the oceans billions of years ago. Evolution is the outcome of the interaction of mutation, genetic recombination, chromosomal abnormalities, reproductive isolation and natural selection. Human beings belong to a Hominidae family, including a single genus Homo.

Carleton S. Coon in \(1962\) recognised and divided humans into four major races, namely mongoloid, negroid, caucasoid and australoid. Paleoanthropology is an interdisciplinary branch of anthropology that studies the origins and predecessors of the present human species, using fossils and other remains.

Origin of the Evolution of Man

The primates originated from a small terrestrial shrew-like insectivore at the beginning of the tertiary period about (65) million years ago. The primate evolution begins in the Eocene of the Tertiary period ((60-75) million years ago) in evergreen forests. The place of origin of humans is great controversy. The fossils of humans were obtained from Africa, Asia and Europe, but most probably, the origin of humans occurred in Central Asia, China, Java and India (Shivalik hills).

The first primates on Earth appeared somehow \(55\) million years ago, about \(10\) million years after dinosaurs vanished from Earth. The first orangutans split from what became the human branch of the primate family tree perhaps \(10\) million years ago; gorillas appeared \(8\) million years ago and diverged from humans common ancestor. The evolutionary history of man is written into our genome. The human genome looks the way it does because of all the genetic changes that have affected our ancestors. Homo sapiens is the only extant species of the genus Homo, but from where it came has been a topic of much debate.

History of Man

Modern humans originated in Africa for the past \(200,000\) years and evolved from their most recent ancestor, Homo erectus. Homo erectus is a lost species of human that lived between \(1.9\) million and \(135,000\) years ago. Two key models have been suggested to describe the Evolution of Homo sapiens. These are the Out of Africa model and the Multi-regional model.

Stages of the Evolution of Man

The genus of a human being today is named Homo, and the man today is called Homo sapiens. The primary resource for detailing human evolution is through fossil records and morphological, physiological and embryological studies. Single-celled organisms evolved into more complex multicellular life, and then man gradually evolved from some unknown mammalian ancestor and reached the pinnacle of evolutionary fabric. Among mammals, humans are very much related to primates like the orangutan. The three species of very early hominids, Ardipithecus, Sahelanthropus, and Orrorin, have made news in the late \({20^{{\rm{th}}}}\) and early \({21^{{\rm{st}}}}\) centuries. The oldest of the three species was Sahelanthropus, and the youngest of the three species was Ardipithecus.

The ancestors to which humans belong are called Hominidae. In the Miocene age, Hominidae came apart from the Pongidae (apes) family. Dryopethicus was the earliest in man’s Evolution, and some believe him to be the common ancestor of man and apes.

Dryopithecus

1. Dryopithecus is recognised as the earliest predecessor of man. Dryopithecus and Ramapithecus existed \(15\) million years ago.
2. They were hairy and walked similar to gorillas and chimpanzees.
3. The genus Dryopithecus refers to oak wood apes; they lived in heavy forests so that the members could have predominantly been herbivores.
4. Dryopithecus is more similar to apes and lived in China, Africa, Europe and India.

Fig: Dryopithecus

Ramapithecus

1. Their first ruins were discovered from the Shivalik range in Punjab and later in Africa and Saudi Arabia.
2. They lived on open grasslands.
3. They were more similar to man, understood by their practice of hands for food and defence.

Fig: Ramapithecus

Australopithecus

1. The impression of this genus was first discovered in \(1924\) in South Africa.
2. They used to live on the grasslands, used stones as a weapon and walked erect.
3. They were \(4\) feet long and weighed \(60-80\) pounds.
4. A few of the bones were discovered differently.
5. They were the first ape-man.

Fig: Australopithecus

Homo habilis (Handyman or able man or skilful man or the toolmaker)

1. The fossils of Homo habilis were obtained from Pleistocene rocks of Olduvi Gorge in East  Africa. It also obtained fossils of Homo habilis from the East side of Lake Turkana in Kenya.
2. They had a face like their ancestors.
3. The skull and brain size show that they may have been capable of speaking.
4. The cranial capacity was \(700 – 800{\rm{ cc}},\) which lived in Africa about two million years ago.
5. Homo habilis is recognised as the Handyman because they first build and use tools.
6. They were around \(5\) feet tall and erect.
7. Homo habilis was carnivorous and had begun hunting for meat.

Fig: Homo habilis

Homo erectus (Erect man)

1. The first impression of Homo erectus came across in Java in \(1891.\) These were entitled Pithecanthropus erectus.
2. Homo erectus species include Java man, Peking man, Heidelberg man, Algerian or Atlantic man.
3. Homo erectus is considered the direct ancestor of modern man. It evolved from H. habilis about \(1.7\) million years ago in the Pleistocene.
4. They were the first human species to have a fleshy nose.
5. Its brain capacities are similar to the modern man at \(1300{\rm{ cc}}\)
6. They were the first ones to walk upright and stand erect.
7. There was an indication of collective huntings, also proof of the use of fire.
8. Homo erectus is supposed to dwell in caves.

Fig: Homo erectus

Neanderthal Man (Homo sapiens neanderthalensis)

1. Fossils of Neanderthal man were discovered by C Fuhlrott \((1856)\) from Neander Valley in Germany.
2. They had a brain size bigger than modern man and were gigantic, also had huge heads and jaws and were very dominant and muscular.
3. They were carnivores, and they also caved dwellers, but their caves were extra comfortable.
4. They used hides to guard their bodies and buried their dead.
5. They used to live in groups and hunted for food gathering.
6. Neanderthal walked upright with bipedal movement.

Fig: Neanderthal Man

Homo sapiens sapiens (Modern man)

1. The living modern man first appeared about \(10,000\) years ago in the Caspian Sea and Mediterranean sea regions.
2. Agriculture came about \(10,000\) years back, and human agreement started.
3. They were omnivores, had expert hands, developed the power of thinking, producing art, more sophisticated tools and sentiments.
4. They became slighter in size, and the brain size reduced to \(1300{\rm{ cc}}{\rm{.}}\)

Fig: Homo sapiens

Fig: Different Stages of Evolution of Man

Evolution is not an object of the past and is ongoing even now. Humans are undergoing natural selection for many diverse traits based on their life and environment in the current. It is said that the jaw size is reducing, and the wisdom teeth will soon become extinct.

Summary

Evolution is hypothesised to have started in the oceans billions of years ago from simple life forms. The idea of branching descent accounts for homology. The different stages of the Evolution of man are Dryopithecus, Ramapithecus, Australopithecus, Homo habilis, Homo erectus, Homo sapiens neanderthalensis and Homo sapiens sapiens. During the Evolution of entity species, the tale of the Evolution of modern man is fascinating.

FAQs

Q.1. What are the salient features of Modern man?
Ans: 1. They were omnivores, had expert hands, developed the power of thinking, producing art, more sophisticated tools and sentiments.
2. They became slighter in size, and the brain size reduced to \(1300{\rm{ cc}}{\rm{.}}\)

Q.2. What are the factors of human evolution?
Ans: Human Evolution generally depends on natural selection, random genetic drift, mutation, population mating structure, and culture.

Q.3. What are the stages of the evolution of man?
Ans: The stages of the evolution of man are:
a) Dryopithecus
b) Ramapithecus
c) Australopithecus
d) Homo habilis
e) Homo erectus
f) Homo sapiens neanderthalensis
g) Homo sapiens sapiens

Q.4. Who were the earliest known humans?
Ans: Homo habilis is the earliest known human.

Q.5. Did humans evolve from apes?
Ans: No. Humans do not evolve from apes. Humans instead share a common ancestor that lived roughly \(10\) million years ago.

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