Question

select all the correct answers.

humans and monkeys share a close evolutionary relationship. monkeys have tails, which help them balance. humans have tailbones but no tails. what are the likely explanations for this situation?

monkeys and humans share a common ancestor.
the tailbone became vestigial, and the tail disappeared because humans could balance on two legs.
grabbing things with their tails became difficult for humans, so their tails disappeared.
monkeys rely on their tails more than humans, so monkeys have tails while humans dont.
monkeys and humans dont share a common ancestor.

Explanation:

Analyze evolutionary relationships

Using the Comparative Anatomy knowledge point

• Humans and monkeys share a close evolutionary relationship, meaning they share a common ancestor.
• The presence of tailbones (coccyx) in humans and fully formed tails in monkeys supports this shared ancestry.

Evaluate vestigial structures

• The human tailbone is a classic example of a vestigial structure.
• As human ancestors adapted to bipedalism (walking on two legs), the physical tail was no longer needed for balance, leading to its evolutionary reduction over time.

Assess functional reliance

• Monkeys rely heavily on their tails for balance and movement in trees.
• Humans do not have this reliance, which explains why monkeys retained functional tails while humans did not.

Eliminate incorrect options

• The claim that grabbing things with tails became "difficult" implies a Lamarckian view of acquired traits, which is scientifically incorrect.
• The claim that humans and monkeys do not share a common ancestor directly contradicts the premise of their close evolutionary relationship.

Answer:

• Monkeys and humans share a common ancestor. (Correct answer)
• The tailbone became vestigial, and the tail disappeared because humans could balance on two legs. (Correct answer)
• Grabbing things with their tails became difficult for humans, so their tails disappeared.
• Monkeys rely on their tails more than humans, so monkeys have tails while humans don't. (Correct answer)
• Monkeys and humans don't share a common ancestor.