Ask Mr Brain...alll will be explained

Why do humans have five toes and fingers but some animals have only three or four? THOMAS Actually, in common with humans, most animals have five toes or fingers on each limb. This is because all vertebrates are believed to have evolved from a common ancestor. There is actually no evolutionary reason for humans having five fingers or toes instead of three or four or even six or seven.

The reason we, and most other vertebrates, have five toes is that the prehistoric tetrapod (any animal with a backbone and four limbs) we eventually evolved from had five toes. Palaeontologists have recently been surprised to discover tetrapods with as many as eight toes. It is possible that these over-endowed animals were evolutionary dead- ends.

It is thought that a five-toed tetrapod ancestor laid down the skeleton that was to become the basis for all vertebrates. However, they adapted it to suit their different environments and diets.

The feet of horses, cows, goats and other hoofed animals have an extreme adaptation of the vertebrate foot which allows them to run swiftly. They literally walk on tip- toe.

About 55 million years ago, the earliest horse had four toes and over time, the horse has lost all of its toes except the third which is now elongated and forms the lower part of the horse's leg. Similarly, seals and dolphins also have the same skeletal structures, but they are now flippers rather than hands or feet.

Cats, dogs and bears all have five toes. Pandas are unusual in that their forepaws have five claws and an extra 'thumb' - a modified wrist bone which acts much like a human thumb and helps pandas to get a firm grip on their bamboo stems as they eat.