Evolution is one of the most interesting topic of biology, but still we haven't know fully about it. This is very famous question " How organisms developed on this earth? And how a single cell organism becomes a massive animal like a Big Whale? still we can't answer it appropriately. This is also a question " How our solar system look like before the Big Bang theory " It maybe our next topic. The answer of all these questions was " God is the creator " before Charles Darwin proved his theory and written his book ' The origin of species '. But know we know all the creatures on on this earth is result of organic evolution which continue about 3.5 billion years. It is believed that if we include all the flora and fauna existing in the world, about 92% is yet to be explored and discovered. It is really a vast variety of organism. We see or maybe can't see there is vast variety of diversity exists on this earth. If we take an example of rainforest, geographiors believed that these forests have amazing biodiversity. About 1,200 different species are found on nineteen trees sampled in Panama. By this example you can think how many species are living on this planet.
To make their jobs easier, scientists classified organisms according to their similarity and differences. This task of studying the diversity of living organisms can be made easier and more effective if the various organisms are arranged in an orderly manner.
Why do we need 'Classification'
The meaning of classification is to storing things into groups. We classify organisms to make recognition and description easier. It is not possible for biologists to remember characteristics of millions of organisms. So, they starts classifying them on the basis of their similarity and dissimilarity.
For example : You got a candy pack which contains candies of different colour according their test. Suppose candy pack as earth and candies as organisms, it is difficult to identify each candy of that pack. So you start classifying them on the basis of their colour.
Importance of Classification
A) Classification makes easy and convenient to study the wide variety of diversity found on the Earth.
B) With the help of classification we don't have to study all the organisms seperately. We can identify them all by study only one organism from that taxonomic group.
C) Classification helps to understand the interrelationship among different group of organisms.
D) It serves as a base for the development of other biological sciences.
Classification and Evolution
These two terms of biology are very much related to each other. The changes occur in living organisms with time is termed as ' Biological Evolution '. This idea was firstly proposed by Charles Darwin by releasing his book named ' The Origin Of Species '.
The concept of biological evolution synthesize that species are capable changing means there body can be change according to their need for survival. Some groups of organisms with ancient body designs have not changed very much but others have acquired their body design relatively recently. And the organisms which are not change 'very much' but or 'not' is categorized into 'Primitive' group, and the organisms which are changed very much and having a complex body are categorized into 'Advanced' group. Primitive were commonly known as "lower organisms" and advanced were known as "higher organisms"
In the year 1859 a man who give t he term ' Biological evolution '. Which means ' The changes occurred in living organisms over time he has written a book named " The Origin of Species " in which he has explained the concept of biological evolution of organisms. In the first edition of "The Origin of Species" in 1859, Charles Darwin speculated about how natural selection could cause a land mammal to turn into a whale. As a hypothetical example, Darwin used North American black bears, which were known to catch insects by swimming in the water with their mouths open. I can see no difficulty in a race of bears being rendered, by natural selection, more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale," he speculated.The idea didn't go over very well with the public. Darwin was so embarrassed by the ridicule he received that the swimming-bear passage was removed from later editions of the book. Scientists now know that Darwin had the right idea but the wrong animal: Instead of looking at bears, he should have instead been looking at cows and hippopotamuses. Because hippopotamuses has more similar to whale in comparison to bear. For example whale is an aquatic animal and hippopotamuses is not aquatic but they are one of best predators of water.
There are two types of organisms described by Darwin:
I ) Primitive
II) Advanced
I ) Primitive > The organisms which have a simple structure or we can also say that organism which not changes very much with time is known as primitive or 'Lower Organisms'.
II ) Advanced > The organism which have a complete form and advanced than the primitive.
[ NOTE : It means they have developed their body with time ]
Why Organisms change?
We know that the organism change with time, But why they change.
Every organisms in this world developed with time because they faces different types of problem in his life. Development of organism can make them better in something and also make them wrost in something.
We see this world everyday, But we can't see any change. Like trees are looking same, Birds, Dog etc. But actually world is changing everytime. We can't identify the change because that changes are very small. This world is changing because organism of this world is changing. And the organisms are changing because they faces different difficulties in their life. And their needs make them better or wrost in their job.
For example Human :
As we know that we are from monkey family and we look like monkey a little bit. The body of monkies are covered with fur but not of human beings because we start wearing clothes. We have less agility than monkies but we have a sharp brain than a monkey. Because we have use our brain more than monkey in our evolution time.