Evolution
- According to Darwin's Theory of Evolution, changes in animals are caused by natural selection and/or mutation
- those with favorable characteristics will survive to breed: this is natural selection
- the evolution of the horse is the best known example among mammals because it has the most documented fossil record
The Five Main Evolutionary Stages
- Eohippus
- Mesohippus
- Merychippus
- Pliohippus
- Equus
Eohippus: The Dawn Horse
- nicknamed the Dawn Horse
- also called Hyracotherium
- first appeared during the first epoch, or Eocene Epoch,
of the Cenozoic Era (60 to 70 million years ago)
- 12 to 14 inches at the withers (the size of a small dog)
- 4 toes on each front foot, 3 toes on each hind foot (14
toes total)
- arched back, rounded body
- lived in forests and ate soft plants
Mesohippus
- first appeared during the Oligocene Epoch of the Cenozoic
Era (at least 38 million years ago)
- 18 to 22 inches at the withers (the size of a sheep)
- 3 toes on each foot (12 toes total)
- lived in forests and ate soft plants
- name means "middle horse"
Merychippus
- sometimes called the Primitive Plains Horse
- first appeared during the Miocene Epoch of the Cenozioc
Era
- pony sized
- 3 toes on each foot, but walked on a dominate middle toe
- lived on the plains and used its modified teeth to eat
grass
- name means "rudimentary horse"
Pliohippus
- first appeared during the Pliocene Epoch of the Cenozioc
Era
- first one toed horse
- lived on plains and ate grass
- name means "more horse"
- although early equine ancestors were plentiful in the
Americas, and Eohippus is sometimes said to have
originated in North America, pliohippus died out
completely in first North and then South America
- different types developed into modern horse (Equus
caballus) as well as donkeys, zebras, and onagers
Equus and the Primitive Types
- from Pliohippus came Equus caballus, the modern horse, as
well as donkeys, zebras, and onagers
- the four early types of the horse included:
- Primitive Type I which included both the Celtic pony
the European forest horse
- Prezwalski's Horse (Primitive Type II)
- the Wild Horse of Central Asia (Primitive Type III)
- the Caspian pony, as well as the Tarpan (Primitive Type IV)
- the European Forest Horse was the ancestor of the draft breeds
- Prezwalksi's Horse still exists as a subspecies
- Primitive Type III became the Akhal-Teke
- the Caspian pony still exists as well, although centuries of domestication have surely changed it somewhat
- Primitive Type IV, crossed with Type III, eventually produced the Arabian
Zoological Classification of the Modern Horse
| Kingdom: | Animalia
|
| Subkingdom: | Vertebrata
|
| Phylum: | Chordata
|
| Class: | Mammalia
|
| Cohort: | Ferungulata
|
| Order: | Perissodactyla
|
| Family: | Equidae
|
| Genus: | Equus
|
| Species: | Equus caballus
|
| Subspecies: | Equus caballus caballus (domestic horse)
|
Early Domestication
- anthropoligists have evidence that horses were hunted for food during
the "Old Stone Age" (Paleolithic Era) 25,000 years ago.
- horses are thought to have been domesticated after oxen, sheep, goats, donkeys, and camels
- credit for domesticating the horse is given to nomadic tribes in Persia around 3000 B.C.
- the Sumerians of Persia invented the wheel, and used onagers (the wild ass) to conquer Babylon around 2000 B.C.
- the horse entered Egypt in 1680 B.C.
- by 1000 B.C., the Greeks were using horses in battle
- the Greeks invented the snaffle bit
- Xenophon wrote the first book on horsemanship, and his opinions are still valued today
- chariot races were added to the 25th Olympic Games in 750 B.C.
- the Romans invented the curb bit
- Julius Caesar invaded Britain in 55 B.C., bringing the horses that centuries later contributed to the thoroughbred
- according to legend, the prophet Mohammed identified the five mares from which the modern Arabian descends in 600 A.D.