Many of the things dogs carry over from wolf society are useful to their new role; many are not. The most clearly useful, though only up to a point, is the wolf’s innate sense of social rank, and the system of communication that supports this rank structure. Social rank is a consequence of adaptations that many group-dwelling animals have made to the inherent contradictions of living in a group. Being part of a group gives an individual advantages and access to resources he could never commandeer on his own. It also puts him in immediate and constant conflict with members of his own species for those limited resources.
Competition with one’s fellows for limited resources is a nearly universal fact of nature. In species in which individuals can forage and defend themselves successfully as loners, it is generally the case that individuals seek to maximize their distance from one another. Males, or females, or mating pairs, set up and furiously defend exclusive territories and keep out all other comers. Whoever is best at seizing and holding ground – whoever manages to keep the other, competing members of his own species the farthest away from him – is the most likely to reproduce and raise viable offspring who will in turn pass on their parents’ genes.
The relentless logic of evolution admits no other outcome: every Carolina wren alive today is the descendant of a Carolina wren that succeeded in fighting off the competition. The nice guys did not merely finish last; they dropped dead, and their nice-guy genes died with them, In group-dwelling animals, undeniably self-interested forces hold the group together, but it’s still every wolf for himself when it comes to the struggle to pass on one’s genes to the next generation.
Every wolf in the pack has an evolutionary mandate to claim a mate, produce offspring, and see that his offspring survive – and that inevitably means survive at the expense of the other guys. And in the wolf pack, the other guy is not over the next hill; he’s lying a few feet away. The situation is inherently explosive. The wolf pack is a tightly packed powder keg of competing interests. Every member of the pack has an interest in being the only member to breed and produce offspring.
At the same time, wolves need the pack. Wolves that hunt very large prey such as moose may form packs with as many as twenty or thirty members, but even when the food supply consists of smaller game, cooperative hunting by smaller packs of four to seven brings in more food than the sum of those four to seven wolves operating on their own could manage. There is also an evolutionary bootstrap process at work in favor of group formation: groups themselves become a force that favors groups, for packs can defend large territories, and only other groups then have the wherewithal to resist that otherwise superior force. When everyone else is a member of a territorial group, the lone wolf is in big trouble, for he now doesn’t have a prayer of claiming and holding any substantial territory on his own.