Horses are a precocial species, which is to say they are capable of standing and running within a short time after birth. Man is the opposite, an altricial species. Years after birth, he is still dependent on others to carry, feed, and protect him from harm.
Horses have the largest eyes of any land mammal, providing a range of vision greater than 350 degrees. Their ears rotate up to 180 degrees, allowing them to hear in all directions without having to move their heads. By contrast, man strains to see what is directly before him and is often fatally deaf to all sounds but those that please him.
Horses walk at four miles an hour, trot at eight miles an hour, and gallop at twenty-five to thirty miles an hour. They can sleep standing up or lying down, and require only an hour or two of REM sleep every few days to meet their minimum requirements. Man, meanwhile, hesitates to walk a city block under his own power and requires 14-16 hours of REM sleep per week just to stave off idiocy.
Horses are prey animals, evolved over millions of years to survive by dint of attentiveness and flight. Man is a predator. Whenever a prey animal catches his attention, his deepest instinct is to hunt it down and eat it.
Given these differences, can the mysterious partnership that developed between horses and men over the centuries be viewed as anything other than a miracle?