does anyone know?

Question

why have horses evolved to become taller and evolved to have no toes? Is it so that they can run faster or something?

Answer 1

Horse evolution was characterised by a reduction in the number of toes, from five per foot, to three per foot, to only one toe per foot (late Miocene 5.3 million years ago); essentially, the animal was standing on tiptoe. One of the first true horse species was the tiny Hyracotherium, which had 4 toes on each front foot (missing the thumb) and 3 toes on each back foot (missing toes 1 and 5). Over about five million years, this early equids evolved into the Orohippus. The 5th fingers vanished, and new grinding teeth evolved. This was significant in that it signaled a transition to improved browsing of tougher plant material, allowing grazing of not just leafy plants but also tougher plains grasses. Thus the proto-horses changed from leaf-eating forest-dwellers to grass-eating inhabitants of the Great Plains.

By the Pleistocene era, as the horse adapted to a drier, prairie environment, the 2nd and 4th toes disappeared on all feet, and horses became bigger. These side toes were shrinking in Hipparion and have vanished in modern horses. All that remains are a set of small vestigial bones on either side of the cannon (metacarpal or metatarsal) bone, known informally as splint bones, which are a frequent source of splints, a common injury in the modern horse.