Wolves and Dogs
Image Credit: Wiki
The mystery of dog domestication and tameness has always fascinated me. The transformation of one animal species-wolves, into another –dogs probably, according to geneticists, started in China from three female wolves. A combination of information from both archaeologists and geneticists came up with some interesting facts.
Genetically, dogs are wolves, but in many other ways, dogs are something else altogether. Mentally, physically and behaviorally dogs show considerable differences. A wolf does not reach sexual maturity until it is about 2 years old; dogs can begin mating as young as 6 months old.
Wolves-both males and females can only mate once a year. These differences between wolves and dogs are the result of variations in hormonal flows.
Raymond Coppinger, a biologist states that the transformation of wolves to dogs probably took place around 15,000 years ago. He mentions that this happened due to fairly good- sized aggregations of people in permanent settlements. These people created low-grade waste dumps which in turn attracted scavengers. Thus wolves whose flight distances were lower than others came into contact with humans and the tamer-ones adapted to humans living in close proximity. Natural selection took over and the wolves that could survive from feeding off food -dumps would begin to differ from those wolves whose flight distances would not permit them to be that close to humans. These ‘tamer’ wolves then reproduced with each other and their tameness became more pronounced. The tamer wolf evolved with a smaller brain and smaller skull. This was because a larger brain was not needed to scavenge in the dump. The smaller wolf would stay longer at the dump and run far less than the larger one, which if surprised would run away sooner and farther and stay away longer.
According to biologists, permanent settlements are needed to create the niche that transformed a few wolves into dogs. But why the quality called tameness? What caused some of the genes of wolves to express themselves differently, at different times? Biologists believe that the thyroid gland is the key to domestication. Wolves who had a higher stress tolerance that resulted from being around people would presumably have different rhythms of the thyroid hormone. This is turn would promote other physical and psychological changes- leading to the domestication process.
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Text Copyright © 2012 Claudia Bensimoun