What is the example of adaptation and evolution?

Answer 1

A common example of evolutionary adaptation is that of the giraffe population eventually having longer necks, even though they have the same number of vertebrae as humans and most other mammals.

Evolution is driven by two things: random mutation and natural selection. Mutations add to the variability within a population and natural selection is like a filter that selects and propagates adaptive traits that provide some competitive advantage to individuals that have it.

To elaborate on the above example, there is naturally occurring variation within a giraffe population (as there is within any species), so that some individuals are born with slightly longer necks than others. During drought or famine, these are better able to reach higher branches on trees, gaining more food energy to survive and reproduce. In subsequent generations that inherit these traits, still others may be born with slightly longer necks than average, and thereby gain further competitive advantage for themselves and their offspring. Over the course of many generations, those with better survival traits increase in number, while those without it decline in number.

It is worth noting that, while an individual can be born with an adaptation, evolution does not apply to individuals; evolution pertains to gene pools within populations or species, and occurs over many generations.