what is meant by the term evolutionary fitness?

Question

If possible could you provide an example.

Answer 1

You are an example of the evolutionary fitness of your parents. They maximized their " inclusive fitness " by passing genes to their progeny; you, for one. That is all it is; surviving to reproduce/replicate.

Answer 2

Fitness is a concept describing the consequences of natural selection - individuals that do not have genetic traits favorable for survival produce fewer viable offspring. The fitness of an individual is the number of that individual's offspring that reproduce, in comparison to other individuals of the same species.

So, Let's say there are two phenotypes of the same species, one the size of a basketball, and another the size of a soccer ball, and this species requires hollow trees for nesting. The soccer-sized phenotype produces two offspring on average, and the basketball-sized phenotype produced four offspring on average.

In an environment where the trees have a diameter that is usually smaller than a basketball, but bigger than a soccer ball, the soccer ball phenotype will will have a higher fitness, because most of the trees are too small for the basketball phenotype to build a nest. In a separate environment dominated by trees that are much wider than a basketball, both phenotypes can find suitable nesting spots, but the basketball phenotype will produce twice as many offspring per pair, so it is likely to have higher fitness in this environment.

Answer 3

Evolutionary fitness just means how well an organism can reproduce. If say, animal A, for both biological and environmental reasons can produce more offspring than animals B, then animal A is more "fit."