Horses


 * Adaptation of Horses **

Horses have developed a lot of adaptations because their predators and their habitat have changed over millions of years. Their legs, eyes and hooves are the three most interesting adaptations of the horse.

The primitive horse probably stood at about 12 hands (120 cm) tall. The first horse was small with short legs. Horses started to live in the grass land instead of the forest so slowly they grew taller and stronger to run faster. The reason that they needed to grow taller was to run away from predators. The horses with longer legs survived and the horses with shorter legs were eaten. Their limbs are levered to muscle and their long leg bones pivot on their joints which focuses movement to the front and back to increase movement and power. Horses have large eyes on the side of their head. Like most prey, horses have a wide range of sight so they can see everywhere except right behind them. This enables them to see and escape predators quickly. Horses react with fight or flight, so either they kick whatever is chasing them or they run away. **Hooves** Over millions of years horses have grown hooves to protect their feet and to run faster. At this time, they had four toes and they were no taller than a dog. The extra three toes moved up the horse's leg and shrunk until you could not see them any more. When they lived in the forest it was better to have four toes so they could weave through the trees but when they started to live in the grassland their extra three toes were unnecessary when they needed to run faster in a straight line.
 * Legs **
 * Eyes **

**References** www.britannica.com/EBchecked/topic/272156/horse/10356/Anatomical-adaptations (accessed 22/3/11) darwiniana.org/horses.htm (accessed 24/3/11) www.horsewyse.com.au/howhorsessee.html (accessed 24/3/11) Pictures from google images searches for: "horses running", "horses eyes","horses toes" (accessed 11/4/11)