Individuals whose characteristics are well-suited to their environment survive. Individuals whose characteristics ar not well-suited to their environment either die or leave fewer offspring. This principle Darwin called survival of the fittest.

how i rewrite this definition in fewer sentences?

thanks a lot Ms. sue :)

You're very welcome, Shreya.

Darwin's survival of the fittest principle states that individuals with favorable traits for their environment survive and reproduce, while those less suited to their surroundings either perish or have fewer offspring.

In natural selection, individuals with advantageous traits survive and reproduce, while those with disadvantageous traits do not. This is referred to as the principle of "survival of the fittest" by Darwin.

Darwin's survival of the fittest means that individuals that adapt to their environment will survive. Others will not survive.