Organisms change over time. Some of these changes make no difference to the success or failure of the organisms that inherit them; other changes do. Take a group of antelopes in which one individual has longer legs than its siblings. Those longer legs make the individual better at escaping from predators, hence giving it an advantage in the survival stakes. Its descendants inherit this feature and are better able to survive as a consequence. Those longer legs have thus become an 'adaptation'. Their evolution means that this particular lineage of antelopes has adapted to its conditions, thanks to its development of this feature.
Over the generations, the individual components of the genetic code within a species change, or mutate. So far as we know, mutations may provide no evolutionary advantage at all. They may be disadvantageous, in which case they are weeded out via natural selection; or they may be advantageous, in which case they persist through the generations.
Choose the most appropriate answer to the following question.
How have antelopes adapted to get better at escaping from predators?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → The long legs of the antelopes help them run faster and have become an adaptation
The passage takes an antelope with longer legs than its siblings: the longer legs make it better at escaping from predators, its descendants inherit this feature, and so the longer legs "have thus become an 'adaptation'".
Why the Other Options are Incorrect?
Option 2: Their horns help them defeat predators — Incorrect. Not mentioned: the passage says nothing about horns; the antelopes escape by running, not by fighting.
Option 3: They have no advantageous mutations — Incorrect. Contradicted: the longer legs are an advantageous change that persists through the generations.
Option 4: They have a keen sense of smell — Incorrect. Not mentioned: the passage says nothing about the antelopes' sense of smell.