the theory of natural selection (survival of the fittest) states that

In the first edition of The Origin of Species, Darwin said little about the brain yet in his notes, he frequently refers to the brain as the organ of thought and behaviour and to heredity of behaviour as being dependent on the heredity of our brain structure. He did not know that genes existed, but he could see that many traits are heritably passed from parents to offspring. Darwin chose the name ‘natural selection’ in contrast to ‘artificial selection’ which is controlled by humans, for example to crossbreed animals for reaching specific visual or performance levels.

This means that if an environment changes, the traits that enhance survival in that environment will also gradually change or evolve. Natural selection is sometimes summed up as ‘survival of the fittest’ because only the ‘fittest’ organisms-those most suited to their environment-are the ones that reproduce successfully and are most likely to pass on their traits to the next generation. Those that are lacking in such fitness, on the other hand, either do not reach an age when they can reproduce or produce fewer offspring than their counterparts. Those that are physically better equipped to survive grow to maturity and reproduce.

According to the theory of natural selection, organisms produce more offspring than the environment can sustain for survival.

He and Alfred Russel Wallace, a scientist working on the same topic, proposed that evolution occurs because of a phenomenon they described as natural selection. Charles Darwin 1809-1882 Credit: IntroductionĮvolution did not reach the status of being a scientific theory until Charles Darwin published his famous book On the Origin of Species in 1859.

The theory of natural selection (survival of the fittest) states that