Jared Diamond - Guns, Germs & Steel

I 7 Z • GUNS, GERMS, AND STEEL
are much more uniformly so.) Zebras have the unpleasant habit of biting a person and not letting go. They thereby injure even more American zoo-keepers each year than do tigers! Zebras are also virtually impossible to lasso with a rope—even for cowboys who win rodeo championships by lassoing horses—because of their unfailing ability to watch the rope noose fly toward them and then to duck their head out of the way.
Hence it has rarely (if ever) been possible to saddle or ride a zebra, and; South Africans' enthusiasm for their domestication waned. UnpredictaWy aggressive behavior on the part of a large and potentially dangerous mammal is also part of the reason why the initially so promising modern experiments in domesticating elk and eland have not been more successful.
Tendency to Panic. Big mammalian herbivore species react to danger J from predators or humans in different ways. Some species are nerve fast, and programmed for instant flight when they perceive a threat.' species are slower, less nervous, seek protection in herds, stand theif| ground when threatened, and don't run until necessary. Most species deer and antelope (with the conspicuous exception of reindeer) are of 1 former type, while sheep and goats are of the latter.
Naturally, the nervous species are difficult to keep in captivity. If into an enclosure, they are likely to panic, and either die of shock or bat themselves to death against the fence in their attempts to escape, true, for example, of gazelles, which for thousands of years were the i frequently hunted game species in some parts of the Fertile Crescent.' is no mammal species that the first settled peoples of that area had opportunity to domesticate than gazelles. But no gazelle species has been domesticated. Just imagine trying to herd an animal that blindly bashes itself against walls, can leap up to nearly 30 feet, and i run at a speed of 50 miles per hour!
Social Structure. Almost all species of domesticated large prove to be ones whose wild ancestors share three social charac they live in herds; they maintain a well-developed dominance among herd members; and the herds occupy overlapping home ra rather than mutually exclusive territories. For example, herds of horses consist of one stallion, up to half a dozen mares, and their Mare A is dominant over mares B, C, D, and E; mare B is submissive tt»| but dominant over C, D, and E; C is submissive to B and A but dc over D and E; and so on. When the herd is on the move, its maintain a stereotyped order: in the rear, the stallion; in the front, the

ZEBRAS AND UNHAPPY MARRIAGES • I 7 3
nking female, followed by her foals in order of age, with the youngest first– and behind her, the other mares in order of rank, each followed by her foals in order of age. In that way, many adults can coexist in the herd without constant fighting and with each knowing its rank.
That social structure is ideal for domestication, because humans in effect take over the dominance hierarchy. Domestic horses of a pack line follow the human leader as they would normally follow the top-ranking female. Herds or packs of sheep, goats, cows, and ancestral dogs (wolves) have a similar hierarchy. As young animals grow up in such a herd, they imprint on the animals that they regularly see nearby. Under wild conditions those are members of their own species, but captive young herd animals also see humans nearby and imprint on humans as well.
Such social animals lend themselves to herding. Since they are tolerant of each other, they can be bunched up. Since they instinctively follow a dominant leader and will imprint on humans as that leader, they can readily be driven by a shepherd or sheepdog. Herd animals do well when penned in crowded conditions, because they are accustomed to living in densely packed groups in the wild.
In contrast, members of most solitary territorial animal species cannot be herded. They do not tolerate each other, they do not imprint on humans, and they are not instinctively submissive. Who ever saw a line of cats (solitary and territorial in the wild) following a human or allowing themselves to be herded by a human? Every cat lover knows that cats are not submissive to humans in the way dogs instinctively are. Cats and ferrets are the sole territorial mammal species that were domesticated, because our motive for doing so was not to herd them in large groups raised for food but to keep them as solitary hunters or pets.
While most solitary territorial species thus haven't been domesticated, it's not conversely the case that most herd species can be domesticated. Most can't, for one of several additional reasons.
First, herds of many species don't have overlapping home ranges but instead maintain exclusive territories against other herds. It's no more possible to pen two such herds together than to pen two males of a solitary species.
Second, many species that live in herds for part of the year are territorial m the breeding season, when they fight and do not tolerate each other's presence. That's true of most deer and antelope species (again with the exception of reindeer), and it's one of the main factors that has disqualified

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all the social antelope species for which Africa is famous from being domesticated. While one's first association to African antelope is "vast dense herds spreading across the horizon," in fact the males of those herds space themselves into territories and fight fiercely with each other when breeding. Hence those antelope cannot be maintained in crowded enclosures in captivity, as can sheep or goats or cattle. Territorial behavior similarly combines with a fierce disposition and a slow growth rate to banish rhinos from the farmyard.
Finally, many herd species, including again most deer and antelope, do not have a well-defined dominance hierarchy and are not instinctively prepared to become imprinted on a dominant leader (hence to become misim-printed on humans). As a result, though many deer and antelope species-have been tamed (think of all those true Bambi stories), one never sees such tame deer and antelope driven in herds like sheep. That problem also derailed domestication of North American bighorn sheep, which belong to the same genus as Asiatic mouflon sheep, ancestor of our domestic sheep. Bighorn sheep are suitable to us and similar to mouflons in most respects-] except a crucial one: they lack the mouflon's stereotypical behavior; whereby some individuals behave submissively toward other individuals whose dominance they acknowledge.
let's now return to the problem I posed at the outset of this chapt Initially, one of the most puzzling features of animal domestication is seeming arbitrariness with which some species have been domesticat while their close relatives have not. It turns out that all but a few candii| dates for domestication have been eliminated by the Anna Karenina princi4| pie. Humans and most animal species make an unhappy marriage, for onfrl or more of many possible reasons: the animal's diet, growth rate, matiftp| habits, disposition, tendency to panic, and several distinct features social organization. Only a small percentage of wild mammal sj ended up in happy marriages with humans, by virtue of compatibility' all those separate counts.
Eurasian peoples happened to inherit many more species of don ticable large wild mammalian herbivores than did peoples of the continents. That outcome, with all of its momentous advantages for asian societies, stemmed from three basic facts of mammalian geograf history, and biology. First, Eurasia, befitting its large area and ecolo-

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gy started out with the most candidates. Second, Australia and the but not Eurasia or Africa, lost most of their candidates in a Americas) ^i"
sive wave of late-Pleistocene extinctions—possibly because the mam-Is of the former continents had the misfortune to be first exposed to h mans suddenly and late in our evolutionary history, when our hunting skills were already highly developed. Finally, a higher percentage of the rviving candidates proved suitable for domestication on Eurasia than on the other continents. An examination of the candidates that were never domesticated, such as Africa's big herd-forming mammals, reveals particular reasons that disqualified each of them. Thus, Tolstoy would have approved of the insight offered in another context by an earlier author, Saint Matthew: "Many are called, but few are chosen."