One of your professors says that fleas jump so high because they have specially adapted leg structures and muscles.But your other professor says that fleas jump high because evolution selected for individuals with genes that helped them avoid being damaged by the scratching behavior of their host.So -- why do fleas jump high?

Question

Quizplus · Accepted Answer

Both professors are correct in their statements, but they are addressing different levels of causation. The proximate cause of fleas being able to jump high is due to their specifically adapted leg structures and muscles. The ultimate cause for this adaptation is due to the fact that fleas needed to be able to quickly move away from their host's scratching behavior in order to survive and reproduce. Therefore, the combined answer is D: The proximate cause is that they have specially adapted leg structures and muscles, and the ultimate cause is that evolution selected for individuals with genes that helped them avoid being damaged by the scratching behavior of their host.

One of Your Professors Says That Fleas Jump So High