Psychologist Jordan Peterson says lobsters help to explain why human hierarchies exist – do they? - 2018-01-24
However, we know that the human brain is hugely malleable and that behaviour and society can influence how it develops. Even how much serotonin we produce is a product of many interior and exterior factors. For example, "stereotype threat" is a process by which people feel anxiety about skills that they perceive to be associated with members of another group. We know such negative feelings actually change brain activity. One study showed that people who perceived themselves as being of lower status than others had different volumes of grey matter in brain regions involved in experiencing emotions and reacting to stress than those who did not.
So believing that it is "natural" that some people are "losers" because that's what lobsters do can have dire consequences. Some people may continue to see themselves as inferior to the guy who bullied them in school, while their brains adapt to this "reality". If we instead chose to believe that all humans are unique and equal – and we have the power to make society fairer – this will change our brains too. It is a clear example of how attitudes can alter both brains and behaviour.
Regarding "continuity", there is continuity in evolution the same way that there is continuity in families. Your grandparents "continue" through your parents and these "continue" through you. Our last common ancestor with the lobster was an animal that existed 350m years ago and it was the first animal that developed an intestine. This is the main organ we have in common – not serotonin and definitely not the nervous system.