A Brief History of Evolution

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Evolution basically suggests that the populations of all living beings and species change over time. And when we think of evolution, most of us think of Charles Darwin. Charles Darwin explained his theory of evolution in a book called “On the Origin of Species”, in which he proposed that species evolve and all living things descend from a common ancestor.

Not only did Darwin suggest the theory of evolution, he also suggested a method of evolution- natural selection. Natural selection allowed the traits that helped organisms survive in their conditions to pass on to next generations and become more common in a population over many years.

Darwin’s Natural selection theory was based on several observations:

<!--[if !supportLists]-->·         <!--[endif]-->Characteristics are heritable and passed on from parents to offspring, and now we know this occurs due to passing on of genes.

<!--[if !supportLists]-->·         <!--[endif]-->Very few of the produced offspring actually survive. Organisms are capable of producing more offspring than the environment can support, which leads to competition for the limited resources in each generation.

<!--[if !supportLists]-->·         <!--[endif]-->Offspring differ in their heritable traits. Any generation’s offspring will be different (at least slightly) from one another in their characteristics, and many of their traits will be heritable.

Based on these observations, Darwin concluded that in a population, some offspring will have specific traits that help them survive and reproduce in their environment, and will produce more offspring, which will also have these helpful traits, than others. Since these traits are hereditary, these offspring will also reproduce and survive better, leading to another generation, most of which will contain these traits. Over many generations, these traits will continue passing on, till the whole population becomes adapted to their environment.

Natural selection depends on the environment, as it favors the traits beneficial to the species in their environment. For natural selection to act on a trait, there must first be a difference in traits of a species, which have to be heritable. These variations come from random mutations or changes in the DNA sequence.

Groups of a single population may get isolated from one another due to geographical barriers, and they can no longer interbreed. Their environments also differ from one another. So in each environment, natural selection will favour different traits, and over many generations, the difference in traits can be so vast that the two groups are considered separate species.

Scientists think that this process has repeated numerous times over millions of years, which led to the diversity of life on Earth.

 

References: Khan Academy, “The Magic of Reality”- Richard Dawkins

 

-Shrishti Kulkarni

Class 8G

GEAR Innovative International School

 

Posted By : SHRISHTI KULKARNI, Class 7, Vidyarthi Vigyan Manthan
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CHANDRA PRAKASH KOTWAL

I have a question, it is said that man has evolved from monkey, so why we have monkeys.. why some monkeys are not changed to man and why some more monkeys are not changing to man now??
Think... any logic?

Posted on : 14-01-2018 07:15:24

Pranjal Singh

Chandra Prakash it's technically incorrect to say this because the species of monkeys separated from other apes a long time ago. The species of apes also branched into many more species and sub species one of which eventually got converted to you and me while others got converted to something else probably monkeys, gorillas etc

Posted on : 13-02-2018 08:08:49

RAVINDRA NAYEE

Who is the Darwin of 20th century? Give reply immediately

Posted on : 30-03-2018 02:39:05

Himangshu Deka

Pranjal Singh your statement is no doubt a reasonable one, but the main point of Chandra Prakash Kotwal is the logical reason.We all know about the evolution of Giraffe as the theory of 'Survival of fittest' say ,I want to explain a bit about the theory that the Giraffe longed to eat grasses of the tall trees either because of the scarcity of ground grasses or might be any other reason, so how one can say that man evolved fro the apes? Why still apes like monkeys ,gorillas exist? Have they not wanted to evolve like the species of homo sapiens did ?

Posted on : 12-06-2018 07:05:21