A Comparison of the Sensory Development of Wolves (Canis lupus lupus) and Dogs (Canis lupus familiaris):
[…] The timing of sensory development in wolves is usually extrapolated from studies on dogs, since they are members of the same species. However, early developmental differences between these two subspecies have already been identified. […] This means that when wolves begin to explore at 2 wk, they are blind and deaf, and must rely primarily on their sense of smell. Thus, there is a significant alteration of how these subspecies experience their environment during the critical period of socialization. These findings lead to an alternative explanation for the difference in dogs’ and wolves’ abilities to form interspecies social attachments, such as those with humans.
Evident here are genetic differences in the early developmental process between two closely related subspecies. Dogs and wolves develop their senses at the same time, but wolves enter the critical period of socialisation much earlier than dogs; beginning to walk and explore their environment whilst still deaf and blind, unlike dogs:
uMass: “When wolf pups first start to hear, they are frightened of the new sounds initially, and when they first start to see they are also initially afraid of new visual stimuli. As each sense engages, wolf pups experience a new round of sensory shocks that dog puppies do not.” […] Meanwhile, dog pups only begin to explore and walk after all three senses, smell, hearing and sight, are functioning. Overall, “It’s quite startling how different dogs and wolves are from each other at that early age, given how close they are genetically. A litter of dog puppies at two weeks are just basically little puddles, unable to get up or walk around […]
Along with disparities between dogs and wolves, domesticated dog breeds also possess different personalities (as well as large intelligence variation) which originated through selective breeding in just the last few hundred years. These personality differences are not caused by the way in which the mother raises her puppies, they are inborn:
Even as the ears and eyes opened the breeds differed in behavior. Little beagles were irrepressibly friendly. Shetland sheepdogs were most sensitive to a loud voice or the slightest punishment. Wire-haired terriers were so tough and aggressive, even as three-week olds, that I had to wear gloves while playing with them; and finally, Basenjis, barkless dogs originating in Central Africa, were so aloof and independant. To judge by where they spent their time, sniffing and investigating, I was no more important to them than if I were a rubber balloon. When I later tested the dogs, the breed indeed made a difference in their behavior. I took them, when hungry into a room with a bowl of meat. For three minutes I kept them from approaching the meat, then left each dog alone with the food. Indulged terriers and beagles waited longer before eating the meat than did disciplined dogs of the same breeds. None of the shetlands ever ate any of the food, and all of the Basenjis ate as soon as I left.
The implications for human
breeds races are interesting. In human newborns, for instance, Asian (Chinese) babies show different temperamental (“irritable”) patterns: They adapt to almost any position in which they are placed, rather than struggling and/or turning over. In the same studies they would briefly press the nose of various newborns with a cloth, forcing them to breath only with their mouths. Most white (and black) babies fight this by immediately turning away or swiping at the cloth with their hands; reported as normal in Western paediatric textbooks. Although the Chinese babies would simply accept the cloth without a fight. A more in-depth post of these experiments (complete with video) can be found below:
Noteworthy, is that the global fixation index (measure of genetic difference), between Asian dog breeds, such as the phenotypically-distinct Japanese Shiba and Korean Sapsali, is 0.154: Genetic variability in East Asian dogs using microsatellite loci analysis. This is nearly identical to the global genetic distance between various human groups at 0.155: An apportionment of human DNA diversity. This is also less than is observed between Europeans (English) and sub-Saharan Africans (Bantu) at 0.24: Is Homo sapiens polytypic? Human taxonomic diversity and its implications: