Why are the walls of the left ventricle so much larger than the walls of the right ventricle?

The walls of left ventricle is larger than walls of right ventricle because left ventricle pumps blood from the heart to the body.

Explanation:

Heart is a muscular organ that pumps blood in the body. Human heart is divided into four chambers- right atria, right ventricles, left atria and left ventricles.

Left ventricles walls are more thick and numerous than right ventricle. The left ventricle pups blood with more pressure from the heart to the whole body. Right ventricle pumps heart to the lungs and blood flows with less pressure in right ventricles as compared with left ventricles.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.