Evolution of the Horse History of the Horse Equine Science Evolution of the Horse History of the Horse

Questions?? What are the evolutionary changes of horses? How has the climate affected their evolutionary process? How has recent human interaction affected their evolution?

THE EVOLUTION OF THE HORSE (Equus)

Equine Science presentation #1 Classification Equine Science presentation #1

The odd-toed ungulates Horses belong to the order Perissodactyla, the odd-toed ungulates. a mammal with hooves that feature an odd number of toes on the rear feet relatively simple stomachs because they are hindgut fermenters, digesting plant cellulose in their intestines rather than in one or more stomach chambers This group includes horses, zebra, donkeys, rhinos and tapirs White Rhinoceros (Ceratotherium simum) © KHW

Equus The genus Equus includes horses, zebra and donkeys The last remaining branch of a diverse group of equids Similar to the status of Homo sapiens, the last remaining species of a once diverse group of Hominids The evolution of the horse is much better documented than ours The fossil record is very complete

Equine Science presentation #1 Evolution of the horse Eohippus (a.k.a. Hyracotherium) Earliest ancestor to our present horse Small primitive horse about the size of a fox Elongated skull, arched back, shortened tail, four functional toes on front feet, and three toes on hind feet 54 million years old Equine Science presentation #1

Equine Science presentation #1

Equine Science presentation #1 Evolution of the horse Mesohippus Appeared when grasslands formed Larger than Eohippus, teeth further evolved, three toes on front feet, better suited to out run enemies Earth had changed – forest became thinned and grass increased 35 – 40 million years old 24 inches at shoulder Became extinct about 7 million years ago Equine Science presentation #1

Equine Science presentation #1

Equine Science presentation #1

Equine Science presentation #1 Evolution of the horse Merychippus Arose 20 million years ago Evolved in North America Adapted to the hard grasses of the plains Beginning of the grazing horse of today Size: 35 – 40 in., gregarious and lived in herds Developed grinding teeth similar to present day horse, lateral toes disappeared, middle toe thickened and hardened Equine Science presentation #1

Equine Science presentation #1

Equine Science presentation #1 Evolution of the horse Pliohippus Developed ~ 5 million yrs ago First true monodactyl (one-toed animal) Teeth and limbs were the closest to present-day horse Spread into S. America, Asia, Europe, and Africa 8,000 year ago Equus became extinct in the Western Hemisphere and did not return until the Spanish brought horses in 1400’s Equine Science presentation #1

Equus caballus ~2 million years ago Modern day horse Became extinct in N. America ~8,000 yrs ago Was not to return until Spanish arrived in 1400’s

Pleistocene (15,000 to 2 million years ago) This era in the horses evolutionary time frame happened to be during and after the last Ice Age Many animals did not survive this drastic shift in climate This stumps many scientists because horses, due to their size, are prime candidates for extinction (this is shown in the fossil record of other large animal species)

Why did horses survive this drastic shift in climate while other large animals did not?

Pleistocene (15,000 to 2 million years ago) Horses adapted to surviving almost solely off of grasses They evolved a cecum to help digest the cellulose found in stems and leaves of plants The cecum allows horses to survive in very poor-quality areas This adaptation allows them to withstand a high-fiber diet and to avoid competition among other species This may have also lead to the increase in their size

Pleistocene (15,000 to 2 million years ago) Evolved a larger brain that may have been related to more sensitive lips for effective foraging 3-toed to 1-toed helped make them more efficient at fleeing from predators

Pleistocene (15,000 to 2 million years ago) Other traits that evolved were some juvenile characteristics (Neoteny) Higher curiosity Flexibility or adaptability to environmental changes A more playful nature Submissiveness Dependency These characteristics or traits lead to an easier domestication of the horse by man

Pleistocene (15,000 to 2 million years ago) After the Ice Age, approximately 15,000 years ago, the horse became extinct in North America This extinction was due to overhunting by the people occupying North America at the time Horses were close to extinction in Europe and Asia but their domestication saved them as a species

Equine Science presentation #1 Evolution of the horse Four Trends in the Line of Descent Reduction in the number of toes Increase in the size of the cheek teeth Lengthening of the face Increase in body size Evolving along with the modern horse were other species of Equus I.e. donkeys, onager, and zebras Equine Science presentation #1

Equine Science presentation #1 Evolution of the horse Przewalski Horse Rediscovered in Mongolia in 1879 Wild horse who maintained itself in Europe and Asia during 60 million years of evolution Small, heavily built, and yellowish colored with an erect mane Przewalski horse has 66 Chromosomes and the domestic horse has 64 Equine Science presentation #1

Trends in the evolution of the horses Increased size Reduced number of toes and longer legs A stiffer back Equus Merychippus 20Ma

Teeth for grazing Larger teeth and a larger skull to hold them

Teeth for grazing Teeth with bands of hard (enamel) and soft (dentine) material on the crown Open tooth roots permitting continuous growth

Trends in the evolution of the horses The trends correspond to changes in the climate and vegetation of the Earth over the past 55 million years, combined with the arms race between predators and prey. From…….. rich rainforest which covered most of the Earth in which the horses ancestors browsed on leaves and hid from predators. To ……. open savannah grassland where the modern horses grazed grass and had to run from predators.

Evolution of the Horse Did not occur in a straight line Many horse like animals branched off Now one genus is the only surviving branch of a once large evolutionary bush Equus

History and Evolution Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Perissodactyla Family: Equidae Genus: Equus Specie: several

Species Equus caballus True horse Once had several subspecies

Species Equus przewalski Oldest living specie of horse Not discovered until 1879 Russian Captain named Nikolai Przewalski Discovered in Mongolia Ancestor of modern horse Cannot be domesticated Characteristically Dun

Species Equus asinus The true asses and donkeys of northern Africa

Species Equus burchelli Plains Zebra of Africa – “typical” zebra Several Subspecies Wide vertical stripes Thick horizontal stripes on the rump Found in Eastern and Southern Africa

Species Equus grevyi Grevy’s zebra, most horse like zebra Native to Eastern Africa Big Zebra with very narrow vertical stripes & huge ears

Equine Science presentation #1 Evolution 24 min https://www.youtube.com/watch?v=qtX3ir4eWM M Equine Science presentation #1

History, Domestication & Early Use Equine Science presentation #1

Domestication & Early Use When were horses were first used? ~50,000 yrs ago Crow-Magnon hunters would: Herd horses over cliffs Butcher for meat, bone, and hide Skeletal remains ~100,000 horses found in France

Domestication & Early Use When were horses were first domesticated? ~ 4,000 B.C. on Kept for meat and possibly milk For work needs, what proceeded the horse? Ass and Ox More docile and easier to domesticate When were horses first used for labor? ~2,000 B.C. in Mesopotamia

History, Domestication & Early Use The Chinese likely first domesticated horses Horses were initially (even before domestication) used for food. Equine Science presentation #1

Equine Science presentation #1 Domestication: to tame (an animal), especially by generations of breeding, to live in close association with human beings as a pet or work animal and usually creating a dependency so that the animal loses its ability to live in the wild. Equine Science presentation #1

Domestication & Early Use How were horses first controlled? Nose ring Due to effective control of ox by same method Popular chariot method of transportation Why did horse replaced the Ox? Speed

Domestication & Early Use Why did man began to ride the horse? Either for convenience or economy Nose rings were replaced by what? Snaffle Bit Who invented snaffle bit? Romans ~1500 B.C. First time reins were on each side of the neck Stirrups and saddles still unknown at this time

Equine Science presentation #1 History of the Horse Egyptians 1680 BC Dynasty of Shepherd Kind Invention of chariot Replaced donkeys Egyptians had a large responsibility for the spread of domesticated horse Equine Science presentation #1

Equine Science presentation #1

Equine Science presentation #1 History of the Horse Rome Invented the curved bit Horses used in the invasion of Britain 55BC 520-632 AD Mohammed Arabs began to use horses Wild horses of Asia (now extinct) gave rise to the Arabian, Barb, and Turk The Thoroughbred originated from these stocks. Equine Science presentation #1

Uses of the Horse and Inventions Early uses of horses transformed: Travel Warfare Economics Culture Social Organization Political Boundaries Languages Equine Science presentation #1

Equine Science presentation #1 Hippology and War Hippology is the study of horses The use of horses in war (mounted cavalry) probably led to the serious study of equitation Ability of the rider to ride correctly, etc https://www.youtube.com/watch?v=2KlGmPx W8P4 Equine Science presentation #1

History of Horses in the US Horses traveled to the Americas with Columbus on his second voyage. They were necessary for transportation and to carry the early Spaniards on their expeditions. Horses were not here when Columbus “found” America in 1492 Equine Science presentation #1

History of Horses in the US The horses that escaped or were abandoned reverted to a wild state and increased in numbers to become the mustang bands found by early adventurers and Indians as they moved west. Short https://www.youtube.com/watch?v=VKi- 8K_7xwo Long: https://www.youtube.com/watch?v=u5X7iKW DILA Equine Science presentation #1

Horses helped the Indians to kill buffalo and to carry on hostile activities against invaders.

Equine Science presentation #1 Wild Mustangs Equine Science presentation #1

Equine Science presentation #1 Colonists’ Horses European colonists’ brought horses that were used to pull heavy loads (wagons, plows, etc) These types of horses are known as draft horses Equine Science presentation #1

Horses of the Southeast US Large plantations of the southeast US created the need for saddle horses Plantation owners wanted smooth, comfortable horses to ride. Horse racing became popular about this time 1730, plantation owners started importing English racehorses Equine Science presentation #1

Equine Science presentation #1 Horses in the US 1861 Mail Service “Pony Express” began Only operated for 18 months Used during wars Army maintained horses until WWII Equine Science presentation #1

Equine Science presentation #1 Golden Age of the Horse ~1890’s until the large scale mechanization of agriculture The rise of mechanization and commerce led to a rise in the number of horses. A record high of nearly 21.5 million horses in 1915 (USA only) Compared to around 6.9 million today (USA) Equine Science presentation #1

Equine Science presentation #1

The Horseless Carriage Henry Ford starts producing the first affordable automobile in 1908 This ushered in the age of mechanization Leads to a decrease in the number of horses Not until 1950’s do the number of automobiles and tractors surpass the number of horses Horse numbers reached an all time low of 3.1 million in 1960 Equine Science presentation #1

Millions of Horses, Autos, Tractors Equine Science presentation #1

Equine Science presentation #1 Replacing the Horse As the country became more urbanized and the automobile becomes more popular the need for horses as a means of transportation decreases The number of tractors used on farms passes the number of horses used in 1954 Equine Science presentation #1

Equine Science presentation #1 The Horse Today Most horses today are light horse breeds popular for pleasure riding and recreation Texas, Oklahoma, and California have the highest horse populations The Quarter horse, Paint, and Thoroughbred are the three most popular ( & registered) breeds Equine Science presentation #1

Equine Science presentation #1 The future of the Horse Horse populations are rebounding as they become more popular for recreational riding because people have more time and money for leisure activities The need for horses for recreation and sport will be the dominant factor in the future of the horse industry Equine Science presentation #1

Status and Future of the Horse Industry Majority of the world’s horses, donkeys, and mules Not found in the U.S What % of horses in U.S.? 8% What % of donkeys and mules >1%

Status and Future of the Horse Industry How many horses in the world? ~60 million Where are the majority found? More than half are found in Asia and South America Mexico, Europe, and U.S. All have significant populations

Equine Science presentation #1 Assignment Write a one page paper about an experience with a horse(s). Positive experiences Negative experiences Life changing experience Funny story If you have limited experience with horses – what are your impressions of them. What interests you about them? Equine Science presentation #1

Assignment Create a time line from the beginning of the Equus to the modern day horse. Include 2 facts for each of the era’s (Mesohippus, Eohippus, etc) we covered. Use a sheet of computer paper to complete the assignment.