Theories of Human Origin and Evolution

(ANTHROPOLOGY PAPER I)

Syllabus Section: 1.4 Human Evolution and the emergence of Man: Theories of Organic Evolution

Introduction

The biggest question that has been stimulating the human mind is the human race's origins and its destination. What is our origin and what are we going to? Recent paleontological findings and scientific advances attempted to discover the answer to these questions by retracing humanity's past. 

The emergence of Life on the Earth

You should have learned in your previous classes the basic concepts about the creation of the universe, and the creation of life on earth. The Earth is among those planets which revolve around the sun. The theory is that the Earth was created around 4500 million years ago. In one view it was tossed into the sun's gravitational field after an explosion from a star known as Supernova. There was no life on earth for a long time, until the half-life duration. 

What is the term "evolution?

The term “evolution" was first coined by Spencer, the English Philosopher Herbert Spencer, to refer to the historical development of the course of human life. In this case, the evolution of human biology began at the beginning of life. The initial successful development of protoplasm started the process of life, and constant development progressed to complexity, leading to different forms of life with evolved forms.  The development of complex organisms that undergo "gradual change" from the simple primitive types throughout geological time is known as Evolution also known as Organic Evolution.

Early Theories of Evolution (PR Darwinian Theories)

In addition to knowing the time that life began, also important is to understand what the life forms are that originated and how they evolved. There were many theories proposed regarding the origins of life. Let's look at the earlier theories of ANTHROPOLOGY PAPER about evolution.

• Theory of Spontaneous Origin: According to Greek philosophers such as Aristotle, Democritus, and Thales the theory of life is that it has evolved repeatedly from non-living or inanimate things in a random manner.
• The Theory of God's Creation: A Spanish monk Father Suarez proposed this theory. In accordance with Genesis from Genesis of the Old Testament of the Bible, The world was created by a supernatural force. The theory states that all creations, including humans, animals, and plants living on Earth were made over six days. Since every species was designed by God The theory doesn't accept the notion of the origin of the new species from the ancestral forms.
• Theory of Eternity: This is an accepted theory. It holds that certain organisms had parents at the start of time. These organisms are still alive and will be around in the future, as well as to a variety of new ones. According to this theory, the origins of the organisms are timeless and are preserved in a way that is automatic.
• Theory of the virus Some researchers believed that the virus was the primary cause of the birth of life. The viruses have an intermediate stage between non-living and living forms. In nature, viruses are not living, however, when it is able to enter the body cell of a human being, it appears as a living. It is therefore believed that a virus might play an important role in the development of life.
• Theory of Cosmic Origin: Richter developed this theory and was backed by Thomson, Helmholtz, Von Tighe, and many others. The theory suggested that the first seed of life was carried through cosmic particles of other planets. According to these scientists’ meteorites that traveled through the earth's atmosphere contained embryos as well as spores within their midst, that expanded and developed into different kinds of organisms.
• The theorem of Catastrophism or Cataclysm: French Geologist Georges Cuvier proposed this theory. The reason for his observation was the fossil remains of a variety of species. According to his theory, the earth has been subject to massive natural catastrophes at different periods during which a variety of animal species were destroyed. Each time, when the earth was able to settle after a massive disaster, more advanced species of animals emerged to replace the situation. He believes that a sequence of disasters led to shifts, in which the previous set of living animals were replaced by new species of complex structure. 

• Post – Darwinian Theories(EDEN IAS)

Following Darwin's natural selection, many people have focused on different forces of evolution that are not related to that Natural selection. Their theories are all Post - Darwinian Theories.

• The theorem of Isolation (Wagner): Emphasized that geographical isolation plays a significant role in the evolution of species, which encourages breeding and assists in the creation of new species.

• Theory of continuity for Germ the plasm (Weismann): This theory was a direct challenge to Darwin's pangenesis and Lamarck's theory on acquired characters. In this case, Germ remains unchanged and has the ability to create new life. 

• Theorem of Orthogenesis (or) Straight line Evolution (or) Progressive Evolution In the orthogenesis theory, "Variations (or) Evolutionary modifications occur along certain lines, guided by unknown (or) intrinsic mysterious forces. For instance, the human evolutionary line has revealed straight line patterns in the growth of the brain, as well as the perfecting of with these Ethics Integrity and Aptitude

• Theory of Mutation (Hugo De Vries) Darwin did not provide a reason for the origin of variation. Hugo De Vries maintained that evolution occurs through massive, abrupt and discrete shifts (or) changes, and were referred to as Mutation. For more information visit our site EDEN IAS