Which doesn't belong and why?
Emotion, Love, Affection, Bonding, Altruism, Cooperation, Prey-Predator dynamic.
Actually it's a trick question, in my model they all belong although admittedly the final term seems jarring relative to the warm, fuzzy, comforting feeling we get from the others.
I have argued, and I invite argument to the contrary, that the oldest relationship between living organisms, one that predates parent/offspring, male/female, filial, or peer-to-peer, is the relationship between prey and predator, and therefore it serves as the platform for how emotion evolved. Below is an example of how primordial this relationship is.
In my model, emotion is a function of attraction and is organic, in other words, it depends on the body more than the Central Nervous System. In fact, everything about physiology, anatomy and neurology, evolves upon the prey/predator dynamic because making a living, and avoiding being fodder for another organisms' means of making its living is the fundamental mandate essential to evolution. Therefore emotion preceding the centralization of the nervous system is more consistent with the evidence than the idea that as species evolved their centralized nervous systems, emotion then emerged from an enhanced capacity.
I have also argued since the seventies that the hunger circuitry is the means of "grounding" emotional states of attraction. In short, the ingestive circuitry is the main vehicle by which an organism experiences pleasure in emotional experiences. From several years ago the reader might recall the following study confirming this connection:
Furthermore, the pressure that predators put on prey, induces in prey organisms collectivized defensive behaviors, in other words they become more social due to the hunt, and to overcome that increase in their capacity to resist predation, induces in predators collectivized predatory behaviors, in other words they become more social due to the hunt. This is another track wherein the prey/predator dynamic is the basis of emotion and subsequent social configurations.
Meanwhile consensus science is operating from the framework that emotion is a cognitive phenomenon, or in the Panksepp model, that CARE giving is a maternal urge, SEEK is an exploratory urge, RAGE is a defensive urge, so that these are separate and distinct from each other with emotion being a function of neurology and neurochemistry. A more parsimonious explanation that is even more consistent with the understanding of emotion as universal to all living beings and the emerging view thanks to Panksepp that it exists below the cognitive plane, is that it evolved from the prey/predator dynamic. This would mean that the prey/predator dynamic is the basis of Panksepp's affective systems.
Lee Charles Kelleys' comment on this study sums things up nicely:
"Of course if scientists were to entertain the idea that prey and predator operate as two cogs -- or better yet, two polarities --, in the same energetic machinery of life, and that it's all based on the properties of attraction and resistance then the jelly's behavior makes perfect sense."