[gore3000]

What is this nonsense about shells not being part of an organism? Does this mean that insects' exoskeletons are not part of the organism? Or that hair is not part of an organism?"

Are you saying that a woman with long hair is a different species than one with short hair? That a woman with the hair tied up at the top is a different species than one who lets her hair just fall? Mollusks and other shelled animals (tortoises for example) can get out of their shells. The shell says absolutely nothing about the animal inside except perhaps as to its relative size (but then there are small mollusks and they change and make new shells as they grow up).

[js1138]

There are many shell characteristics other than size that can be measured. In fact most shelled creatures are identified by their shell rather than by their internal parts. As for hair length, there are varieties of creatures that have naturally short hair and vice versa. This is not always a species difference, but it is an inherited difference.