AP BIOLOGY

Detailed explanation-1: -In the first four editions of On the Origin of Species, Darwin had used the phrase “natural selection". In Chapter 4 of the 5th edition of The Origin published in 1869, Darwin implies again the synonym: “Natural Selection, or the Survival of the Fittest".

Detailed explanation-2: -In the crudest terms, fitness involves the ability of organisms-or, more rarely, populations or species-to survive and reproduce in the environment in which they find themselves 6–9. The consequence of this survival and reproduction is that organisms contribute genes to the next generation.

Detailed explanation-3: -An adaptation is any heritable trait that helps an organism, such as a plant or animal, survive and reproduce in its environment.

Detailed explanation-4: -Evolutionary biologists use the word fitness to describe how good a particular genotype is at leaving offspring in the next generation relative to other genotypes. So if brown beetles consistently leave more offspring than green beetles because of their color, you’d say that the brown beetles had a higher fitness.