Survival of the fittest
It is the idea that a species will adapt to its environment and over time pass down those adaptations to their offspring. Individuals that don’t adapt will die off before breeding and those poor traits will not be passed on. Eventually, only the desired traits will survive in the population
how survival of the fittest is different to natural selection
Survival of the fittest is the process which by how the species who are best adapted to the environment and the weak breed will most likely be killed by predators, since they’re an easy target while individuals who survive are the ones who are best adapted. The ones who are best adapted to exist in their environment due to the control of variation that is best suited. Natural selection is more of an evolutionary process, which species change over generations to adapt to their environment. For example, some birds live where they have no natural enemies, so over time they lose their ability to fly and ultimately their wings weaken.