Hello guys my questions are those: Are there any dog in America before Columbus? If there are, how different are those from Old World dogs, I mean, we know that humans domesticated dogs from wolfs because there was mutual benefits both dogs and humans. Did any process like that develop America too? How can we differ old and new worlds dogs between each other?
Domestication of dogs in separate continents seems kinda strange to me, I mean, there are completely separate human populations and they both decide that domestication of wolfs will be good.
Yes, there absolutely are! I'm a prehistoric North American archaeologist and we find domesticated dog remains pretty frequently. Evidence suggests that the populations who came from NE Asia during the Pleistocene already had domesticated dogs with them (or that one of the later migratory pulses did), although from my knowledge the earliest dated domesticated dogs come from the Midcontinent and date to ~10,000 years ago. This is about 6,000 years after dog domestication is thought to have occurred in a number of Old World regions. There are a variety of things that can explain this gap, ranging from taphonomy to the relatively ephemeral nature of Paleoindian sites. Another thing to remember is that archaeologically it is difficult to distinguish early domesticated dogs from their wolf cousins, so the bones of a dog companion may look like a wolf or other wild canid when analyzed. But, regardless, I've excavated clearly domesticated dog remains that date between 1,000-2,000 years ago - well before Europeans stumbled on the Americas.
This is a good article a colleague of mine was on covering the topic and the issues related to it. There is a ton of interesting archaeological and genetic evidence cited in there that can get you started down that very interesting path.