Evolution of the Brain in the Animal Kingdom

What significant evolutionary development occurred around 550 million years ago?

• The emergence of radial symmetry

• The development of protective skulls

• The branching off of animals with bilateral symmetry

• The evolution of complex brains

Why did early animals begin to cluster their nerves at one end of their bodies?

• To protect their spinal cords

• To focus sensory organs near the mouth

• To enhance their movement

• To improve their balance

What was a key factor in the evolution of more complex brains?

• The need for faster movement

• The development of stronger limbs

• The growth of larger body sizes

• The increase in sensory organ power

What evolutionary advantage did hardened skulls provide?

• Improved hearing

• Stronger jaws

• Faster movement

• Better camouflage

How did vertebrates diversify after leaving the water?

• They became smaller in size

• They lost their protective skulls

• They developed wings

• They evolved into various species like dinosaurs and dogs