EVOLUTION Flashcards
Define the term ‘evolution’.
It refers to the gradual changes in living organisms over time.
Define Evolutionary Biology.
It is defined as the study of the history of life-forms on earth.
When the process of evolution actually begin?
Evolution began only after the origin of the earth.
Which theory explains the origin of the earth and who proposed it?
The BIG BANG THEORY explains the origin of the earth. It was proposed by Lemaitre.
Explain the Big Bang Theory.
At the beginning of time, the world was believed to a point. This point then explodes about 200 billion years ago which lead to the formation of matter and energy.
How were the different states of matter formed?
During the expansion of the universe, the temperature dropped leading to the condensation of matter.
Which was the first formed matter/ element?
Hydrogen.
Explain the formation of the universe.
Several interactions that include the fusion and condensation of big cosmic clouds lead to the formation of the galaxy. Many such galaxies form the milky way and many such milky ways formed the universe.
How was the solar system originated?
It happened due to the condensation of a cosmic cloud, as per the Condensation Theory or Nebular Hypothesis of Immanuel Kant.
How did the planets and the sun form?
The sun developed from a large whirling mass of cosmic material or a nebula while the planets developed from smaller peripheral condensed cosmic material.
Why did only the central mass become the sun?
Because only this mass had a critical temperature for thermonuclear reactions to occur.
When was the earth formed?
The earth was formed about 4.5 billion years ago.
What do you mean by the density gradient of cosmic material in the solar system?
It means that the clouds with heavier elements condensed nearer to the sun while the clouds with lighter and volatile elements, away from the sun.
How was primitive earth?
Primitive Earth was like a ball of gases of various elements. The heavier elements were found near the core and vice-versa. It had extremely high temperatures, volcanic storms, extreme climate with UV rays.
Explain the difference in the atmosphere now and then.
Today the atmosphere is an oxidizing one while earlier it had been a reducing one.
What is protobiogenesis?
It is the origin of life on the primitive earth.