Final answer:
The option that is NOT an example of evolution is the short-term physiological response to high altitude in humans, as it is acclimatization rather than a genetic change. Beak size change in birds and the loss of hindlimbs in whales are examples of evolution.
Step-by-step explanation:
Among the options provided, the one that is NOT an example of evolution is the third option: When traveling to high altitude, human physiology changes to accommodate lower oxygen levels. This is not evolution but rather an instance of acclimatization, which is a short-term physiological response to environmental change and is not a genetic change passed on from one generation to the next. Evolution is the change in the characteristics of a species over multiple generations and relies on processes such as natural selection.
Both the first option - beak size in a population of birds changing due to reproductive success - and the second option - whales losing their hindlimbs over time - are examples of evolution. These changes represent the alteration of inherited traits within a population across generations, often in response to environmental pressures. Darwin's finches and the evolution of their beak sizes in response to food availability are classic examples of adaptive radiation and natural selection, as observed by Peter and Rosemary Grant in their studies of Galápagos finch populations.