So I'm kinda surprised there's no conclusion on what #2 is. I think a recurring issue is the definition of what makes man the dominant species. I sure as fuck don't know, other than our self awareness and intelligence. Perhaps that's what makes it possible for only one creature to be on top, but that's kind of an unfair advantage.
If all humans disappeared tomorrow, what species would rise to the top as the most abundant and dominant species? Dolphins...nah, sharks keep them in check. Sharks? They're ok but only in water. Lions, tigers, bears...ditto.
I'm thinking mosquitoes. Those fucking things can spread disease and are impossible to eradicate...better than roaches, in that respect. But they can't survive in the cold.
How bout gorillas?
I'm still thinking dogs. Without humans, they'll just breed into the nastiest of the nasty and their pack
mentality will allow them to hunt effectively. Probably better than actual wolves, since they don't need as much food.
People give dogs way too much credit. Because they are gentic mutants made by man for man's specific purposes, they have too many genetic defects. Hip issues, skull issues, deafness, eye issues, blindness, kidney issues, leg issues, back issues, and many are breed specific or family specific. Even the mutts have issues, but not as much as the pure breed dogs.
It is due to man's breeding habits, creating dogs for narrow specialities that often resemble in nature niche predators like Smilodon, often called the Sabre tooth tiger. Smilodon came on scene in the era of megafauna, where the predators were big to take on the even bigger prey.
Smilodon had a stout body, with huge forelimb and chest muscles, exceptional back legs muscles, and a huge neck muscles. It had a mouth that could open wider than any big cat, yet it's teeth, were fragile from side blows. Thus, the thinkig it was a abuse predator that stab it's prey...analysis of it's skeleton showed emmense wear and tear on it's back and rear, meaning there was a lot of torque involved in what they were doing.
What happened? Well, when it's food supply, the mega-herbivores like Mammoths, started dying out, it could not adapt, due to it being a niche predator.
So, taking this knowledge, if dogs were to be successful in the wild, they would probably interbreed until you get something like the Dingo or African Wild dog. Dogs that have a mid range snout and are of medium build. All other dogs like the toy breeds and Giant breeds would have to disappear, as they really serve no purpose. This leaves, the hounds, sight hounds, working dogs like the German Shepard and Doberman, and the terriers and Molosser terriers...these are the dogs that would make up the genetic material for a dog that could be great in the wild...
But, to be number 2, one needs language, the ability to think especially forethought and use tools, and development of culture---Which chmps in the wild have shown the ability for all these.
