Board Thread:General Discussion/@comment-26184563-20130421015649/@comment-995426-20160429220250

No, I'm implying that humans are a clade of fish, by virtue of being a clade of primates, which are a clade of mammals, which are a clade of reptiles, which are a clade of amphibians, which are a clade of fish, to put it in simplified terms. (Again, "all humans are fish, but not all fish are humans.") The funny thing about all that is, though humans are more closely related to coelacanths than to other fish, the reverse is also true&mdash;coelacanths are more related to humans than they are to other fish, because the clade containing both humans and coelacanths branched off as one group before later diversifying.

Also, while humans have indeed changed very much from fish ancestors, there are still so many ways they are similar to the ancestral fish&mdash;two eyes with irises and lenses, a nose (or nostrils), a mouth, a spine, a bony skeleton, and a blood salinity similar to seawater. And many human organs were refashioned from previous fish organs. For example, human lungs evolved from primitive fish lungs...which actually evolved into swim bladders of other bony fish and not vice versa (mind screw, isn't it?).

I think, as humans, we're very conditioned to see everything that's different in others as part of an instinct to recognize and differentiate, but we can easily forget that we're far, far more like a fish than we are like a crab or like an octopus or like a mushroom or like a tree. Of course that does not translate into immediate biological compatibility, as that can change rather quickly over evolution. But it's like a zen experience realizing that all land vertebrates are basically clades of those fish that moved permanently (or semi-permanently) to land, and that everyone who shares a family is more related to each other than they are to anyone outside that family.