Question

In many hairy vertebrates, such as apes, dogs, and rats, the involuntary erection of hair acts as an efficient means of thermoregulation. The erect hairs trap an insulating layer of air against the skin, keeping the animal warm. Humans also display hair erection when cold, though humans are not hairy enough for this reflex to have a significant effect on body temperature. Which statement is true regarding this reflex?

1) It reflects the common ancestry of humans with hairy vertebrates.
2) It suggests humans are less evolved than other hairy vertebrates, because they are not adapted to maintain body temperature.
3) The loss of hairy bodies is an evolutionary disadvantage to humans.
4) The reflex is actually a voluntary response humans manifest during infancy.

Answer 1

It reflects the common ancestry of humans with hairy vertebrates.

Step-by-step explanation:

Evolution is the change in the species with the passage of time. Some species might get extinct and some species might develop the advance character during the evolutionary process.

The evolutionary history of the organisms can be classified on the basis of the paleontological or molecular evidence. The two groups of the organisms can share a common ancestor if they have some similar features with each other. In the given question, it can be concluded that hairy vertebrates and human might have the common ancestor.

Thus, the correct answer is option (a).