I have two dogs. 
Really what kind? Dogs were first found buried next to humans almost 15,000 years ago! That's how long they've been man's best friend. I have one little rescue puppy.
Our dogs are mutts from the pound. I had no idea they were around that long ago. Did they help hunt as well as companionship?
Aw yay, you got yours from the pound also. That's the way to go! I believe they were used to hunt, but I'm not sure. Dogs are related to wolves but they evolved to be the only kind of their species to eat a starch diet in order to keep up with humans! 
I have never understood why people have dogs instead of children, do you know if there is scientific evidence for that?
Haha I'm not sure. My guess would be that dogs love you unconditionally, you can leave them at home alone, and you don't have to pay thousands and thousands to put them through college! haha
I could see that. 
I have a dog but I don't have kids yet, I'm not ready for the full responsibility lol.