Stages of Evolution in Humans

Humans evolution is defined as the gradual transformation of an organism's simple structure into a more complex one. Living things develop from primary, unicellular organisms through a process called evolution.

• Human evolution has a long history.
• It started with Darwin's hypothesis.
• Humans evolved from early hominins to Homo sapiens.
• During this evolution, humans have developed many new characteristics and changed the way of living.

Key Terms: Evolutions, Homo Sapiens, Theories Of Evolution, Darwin’s theory.

---

Evolution

[Click Here for Sample Questions]

Charles Darwin claimed that the mechanism of natural selection drives evolution. According to Darwin's hypothesis, every organism evolves due to numerous small changes that grow over time. There are no scripted records about the prehistoric phase. However, research on the fossil record provides a wealth of crucial knowledge about prehistory.

Also Read:

---

History of Human Evolution

[Click Here for Sample Questions]

As the first known man walked this globe roughly millions of years ago, the evolution of man began. From early hominins or extinct apes, modern humans evolved through several stages of development. Homo is the name of the modern human species, and Homo Sapiens is the name of modern man. The evolution of multicellular animals from simple unicellular living forms took a long time, starting with the primates that gave rise to contemporary humans, who walk on two of their hind limbs.

---

Characteristic of human evolution

[Click Here for Sample Questions]

Over millions of years, our ancestors evolved various characteristics that helped them survive and adapt to changing environments. Some of the key characteristics of human evolution include:

1. Bipedalism

The ability to walk on two feet is a crucial characteristic that distinguishes humans from other primates. Bipedalism allowed our ancestors to travel long distances, use their hands for tool-making and carrying objects, and free up their jaws for speech.

2. Enlarged brain

One of the most significant features of human evolution is the growth and development of our brain, which allows us to develop complex social behaviours, language, and culture. The size and sophistication of the human brain still set us apart from other primates.

3. Tool use

Early humans were adept at using tools for hunting, gathering food, and protecting themselves. Our ancestors used rocks, sticks, and other natural materials to create weapons, clothing, and shelter.

4. Language

Human language is a complex and highly evolved system that enables us to communicate ideas, thoughts, and emotions. Language development allows humans to share knowledge and create complex social structures.

5. Culture

Unlike other animals, humans have developed complex cultural systems that allow us to share knowledge, values, and beliefs. Our ability to create and transmit culture has allowed us to adapt to various environments and survive in harsh conditions.

6. Social behavior

Humans are highly social animals, and complex social interactions have shaped our evolution. We have developed complex cooperation, competition, and hierarchy systems, allowing us to thrive in diverse environments.

7. Longevity 

Humans have longer lifespans and slower maturation rates than other primates. Longevity has allowed us to develop more complex social structures, accumulate knowledge, and pass it down from one generation to the next.

---

Theories of the evolution

[Click Here for Sample Questions]

Theories of the evolution of human beings are based on the fossil record, genetics, and comparative anatomy. The following are some of the most widely accepted theories:

1. Darwin's theory

He proposed the theory of natural selection, which explains that human beings, along with other species, have evolved through the process of natural selection. According to this theory, individuals with beneficial traits have a higher chance of surviving and pro-creating, passing those traits along to their progeny and eventually resulting in the development of new species.

2. Out of Africa

The theory proposes that humans evolved in Africa and then spread to other parts of the world. It is supported by genetic evidence that shows that modern humans are most closely related to African populations.

3. The multiregional

This theory proposes that humans evolved simultaneously in different parts of the world, with gene flow between populations. This theory suggests that all modern humans share a common ancestry.

4. Recent African origin theory

This theory is Also known as the "single-origin hypothesis," According to this theory, modern humans originated in Africa before migrating to other areas of the globe and displacing or mixing with other hominid tribes.

5. Aquatic ape hypothesis

This theory proposes that human evolution was shaped by living near water and spending significant time in aquatic environments. The scientific community does not widely accept this theory.

These theories are constantly refined and updated as new evidence is discovered through research and analysis.

---

Stages in human evolution

[Click Here for Sample Questions]

The following are commonly accepted seven stages of evolution, based on scientific consensus and the fossil record :

1. Sahelanthropus tchadensis (7-6 million years ago)

This is considered the earliest known hominid species, with fossils found in Chad. It had a tiny brain and walked upright but had some ape-like features.

2. Orrorin tugenensis (6 million years ago)

This species, found in Kenya, also walked upright but had longer arms and more ape-like features than later hominids.

3. Ardipithecus ramidus (4.4 million years ago)

This species, found in Ethiopia, is thought to have been able to walk upright and climb trees. It had a tiny brain and some ape-like features.

4. Australopithecus afarensis (3.9-2.9 million years ago)

The discovery of the fossil "Lucy" made this species well-known. Compared to early hominids, they had a more developed brain, although they still exhibited some ape-like traits.

5. Homo habilis (2.8-1.5 million years ago)

This was the first hominid species to use tools, hence its name, "handyman." It had a larger brain than earlier hominids and was likely the ancestor of later Homo species.

6. Homo erectus(1.8 million-300,000 years ago)

This species was the first to leave Africa and spread throughout Asia and Europe. They had a larger brain than Homo habilis and were skilled at making tools and hunting.

7. Homo sapiens (300,000 years ago-present)

This is the species modern humans belong to. They have the giant brain of any hominid species and have developed complex societies, languages, and cultures.

Also Read:

---

Things to remember

• Evolution is the process by which species of an organism develop and change over time, driven by natural selection and other factors
• Some of the key characteristics of human evolution include bipedalism, last brain language, social behaviour and longevity
• The theories of human evolution include Darwin's theory of natural selection, the out-of-Africa theory, the multi-regional theory and the recent African origin theory, the multi-regional theory
• Accepted stages in human evolution based on the Fossil records include Sahelanthropus tchadensis, Orrorin tugenensis, Ardipithecus ramidus, Homo habilis, Homo erectus, Homo sapiens