A Moche vessel with a pair of hairless dogs, dating to about 

 A.D. 750, is one of the earliest in Peru. Why the dogs were prized 

 in prehistoric times is uncertain. People may have believed the 

 warmth of the dog's naked skin could relieve some ailments. 



Raul Apesteguia Collection. Lima; Photograph by Christopher B. Donnan 



nored by earlier artists? That seems un- 

 likely, since they did portray coated dogs, 

 with sleek rather than wrinkled skin. In ad- 

 dition, dozens of mummified dogs from 

 the thousand years before a.d. 750 have 

 been found in Peru and Chile, and none 

 appear to be of the hairless type. 



Could the hairless dogs have suddenly 

 appeared in Peru as a result of an indepen- 

 dent genetic mutation? Since hairless 

 breeds exist elsewhere in the world, this is 

 a possibility. But some or all of these 

 breeds may tum out to be related. So far, 

 the genetic and osteological studies that 

 would determine the relationships have 

 not been carried out. 



A third explanation is that hairless dogs 

 were brought to South America from 

 Mexico sometime in the eighth century. 

 Early contact between the two regions has 

 long been suspected, but proof has been 

 elusive until recently. In 1 990, anthropolo- 

 gists Dorothy Hosier, Heather Lechtman, 

 and Olaf Holm published a comparative 

 metallurgical analysis of ancient artifacts 

 from the two regions, demonstrating that 

 the craft of metalsmithing was introduced 

 into western Mexico about 700 years be- 

 fore Columbus arived in the New World. 

 Techniques of alloying copper and ar- 

 senic, for instance, have a long history in 

 South America but appear quite abruptly 

 in western Mexico. 



Current evidence points to the contact 

 having taken place by sea, rather than by 

 land. At the time the Spaniards arrived, the 

 Salangone kingdom on the coast of 

 Ecuador controlled a lively Pacific coast 

 trade. The Salangone traders plied the wa- 

 ters at least from Colima in Mexico to 

 Chincha in southern Peru. Their vessels 

 were large sailing rafts made of balsa logs, 

 often with a cabin on deck. Francisco 

 Pizarro, the Spanish conqueror of Peru, 

 encountered one such vessel on his south- 

 ward journey into the Inca Empire. His 

 written account indicates that it was carry- 

 ing numerous people, animals, textiles, 

 and precious items. 



Whether the Salangone kingdom 

 stretched back to the eighth century is un- 

 certain, but my own studies have shown 



A Lethal Gene 



The Inca hairless dog 



Donna McClelland 



Dog fanciers recognize two breeds of 

 hairless dogs that ai'e descended from an- 

 cient New World forebears. Both breeds 

 are uncommon, even in their homelands. 

 The Mexican breed, called xoloitzcuintli, is 

 classified in three sizes: standard, minia- 

 ture, and toy (the popular name "Mexican 

 hairless" generally refers to the toy). A sim- 

 ilar Peruvian breed is called the Inca hair- 

 less dog or the Peruvian Inca orchid dog. 

 Some writers claim that to protect the ani- 

 mals from excessive exposure to the sun the 

 Inca kept them in orchid-filled rooms dur- 

 ing the day and allowed them to ran free at 

 night (giving rise to another nickname, 

 "moonflower dog"). This colorful story ap- 

 pears to be a modem invention; it is not 

 supported by any of the early Spanish 

 chronicles. 



The hairless trait is hereditary and dom- 

 inant — a puppy that inherits the gene for 

 hairlessness from just one parent will be 

 bom hairless. If genes for hairlessness are 

 received from both parents, the combina- 

 tion is lethal, and the embryo is resorbed or 

 stillborn. Because of this, every hairless 

 dog carries the gene for hair from one par- 



ent. When two hairless dogs mate and have 

 a litter, on average one-third of their surviv- 

 ing offspring have hair (breeders call them 

 "powderpuffs"). When a powderpuff and a 

 hairless are bred — a routine pairing done to 

 maintain the breed — the litter averages half 

 coated and half hairless. 



Hairless breeds have another abnormal- 

 ity — an incomplete set of teeth. While dogs 

 with coats have ten molars and sixteen pre- 

 molars, modern hairless dogs usually lack 

 or lose their premolars and may even be 

 nearly toothless. The teeth they do have are 

 often set at peculiar angles. Because hair- 

 lessness and faulty dentition regularly ap- 

 pear together, they may both be caused by 

 the same gene. 



Otlier hairiess breeds, such as the Chi- 

 nese crested, may be related to the New 

 World's bald canines. Some breeders spec- 

 ulate that the hairless tait originated in one 

 locale and was then spread as a result of 

 human trade or migration. But the dogs" 

 distribution at widely separated locations 

 suggests that the trait could have arisen 

 more than once as a result of similar genetic 

 mutations.— A. C.-C. 



39 



