Understanding the Panniculus Carnosus Muscle

Humans are unique among mammals, lacking the panniculus carnosus muscle found in many other species. This muscle allows animals like horses to twitch their skin to remove insects. Echidnas use it to roll into a defensive ball. Humans have remnants of this muscle, but it's largely non-functional. Apes, our relatives, also lack this muscle due to their ability to use limbs to swat insects, making the muscle unnecessary. Evolution has favored limb flexibility over maintaining this muscle.

What anatomical feature is highlighted as unique to humans compared to other mammals?

• Opposable thumbs

• Panniculus carnosus muscle

• Walking on two legs

• Large brains

What is the primary function of the panniculus carnosus muscle in animals?

• Enhancing hearing abilities

• Twitching the skin to dislodge insects

• Improving vision

• Aiding in digestion

How does the panniculus carnosus muscle benefit animals in terms of thermoregulation?

• By increasing body temperature

• By reducing body temperature

• By facilitating fast skin twitches

• By enhancing blood circulation

What unique ability do echidnas have due to their panniculus carnosus muscle?

• Flying

• Rolling into a ball

• Climbing trees

• Swimming

Why do humans lack the panniculus carnosus muscle?

• It was lost due to dietary changes

• It was replaced by another muscle

• It is not necessary due to our flexible limbs

• It was never present in human ancestors

Which group of mammals still retains the panniculus carnosus muscle?

• Only humans

• Only marine mammals

• Most primates except apes

• All primates

What evolutionary advantage do apes have that reduces the need for the panniculus carnosus muscle?

• Stronger muscles

• Flexible forelimbs and shoulders

• Better vision

• Larger brains

What is the main reason natural selection did not preserve the panniculus carnosus muscle in apes?

• It caused health issues

• It was too costly to maintain

• It hindered movement

• It provided no survival advantage

What is a vestigial structure?

• A structure that has no function

• A structure that is fully functional

• A structure that is partially functional

• A structure that is overdeveloped

What can humans thank evolution for, according to the video?

• The loss of the panniculus carnosus muscle

• The ability to swim

• The ability to fly

• The development of large brains