Natural selection is the process by which some organisms in a population survive and reproduce, while others do not, based on their bodies and behaviour. It is one of the processes by which ...

The phrase "survival of the fittest" functions principally in evolutionary theory to describe the biological concept of natural selection ... through Principles of Biology when Darwin was working ...

To constitute natural selection, the difference in survival and/or reproduction cannot be due to chance, and it must have the potential consequence of altering the proportions of the different ...