Why do we study Genetics ? Give its historical background ?

There are certain question which come in our mind like :

- Why an elephant always gives birth only to a baby elephant and not some other animal?

Or why a mango seed forms only a mango plant and not any other plant?

Given that they do are the offspring identical to their parents?

Or do they show differences in some of their characteristics?

- Why sibling sometimes look so similar to each other? Or sometimes even so different?

These and several related questions are dealt with, scientifically, in a branch of biology known as Genetics.

Genetics subject deals with the inheritance as well as the variation of characters from parents to offspring.

Inheritance is the process by which characters are passed on from parent to progeny, it is the basis of heredity.

Variation is the degree by which progeny differ from their parents.

Variation means the differences among the members of a species and the progeny of the same parents.

Historical Background : Human knew from as early as $8000$-$1000$ $B$.$C$. that one of the causes of variation was hidden in sexual reproduction.

They exploited the variations that were naturally present in the wild populations of plants and animals to selectively breed and select for organisms that possessed desirable characters.

For example, through artificial selection and domestication from ancestral wild cows, we have well known Indian breeds e.g. Sahiwal cows in Punjab.

Though our ancestors knew about the inheritance of characters and variation, they had very little idea about the scientific basis of these phenomena.