[jacquesm]

In fact, for quite a few fish they do, ditto amphibians and insects too.

Mammals are the exception here, there the environment for replication is an integral part of the body of the parent. But in all those other cases, including, technically, marsupials it isn't.

[kaba0]

Just because it happens outside the ‘parents’ body doesn’t mean the environment does it anymore than a mother being only a filter around the womb and the environment.

An egg is a complex life that can reproduce the whole organism (and actually with energy stored INSIDE, that’s why they are great nutritios value for others)

[cdogl]

The distinction between environment and organism here seems a little arbitrary. The organism’s cells have membranes, but they’re permeable and the organism can’t do its job without an interaction between itself and the environment. Even with the energy stored inside, it requires warmth and atmospheric pressure. I suspect there are any number of counter examples of life forms that challenge the simplicity of this formulation. You could just as easily argue that each cell is a life form unto itself, right?

[kaba0]

Isn’t each cell a life form unto itself? Like there are cell lines from cancer cells that has been living outside their ‘host’ long after the human they were aquired from died (HeLa) They just specialize in an specific environment created and maintained by cells with the same genetic material