The Evolution of the Sense of Touch: Questions, Ideas, Etc.

The sense of touch has with it two aspects that I understand… the sense of texture and hardness, and the sense of temperature. Perhaps there are other aspects… pain? I relegate this to both texture/hardness and temperature. Now, what if it were possible to feel only texture and hardness but not to feel temperature. Or what if I could only detect temperature but not feel the texture and hardness of a surface? Are the two interlinked? That is, can I feel one aspect without the other? Note that the same word, feel, is used for both aspects, as is touch. When I feel something very hot I feel a sensation of pain (assuming it were scalding hot). When I feel something particularly sharp, I might feel pain if I cut myself. If I had neither of these aspects of touch, I might certainly have caused severe if not lethal harm to myself as an unwary child. For these aspects seem necessary, and perhaps during the period of the evolution of life itself there were strange mutations of animal that had only one or the other aspect, or perhaps neither, and I would imagine that these did not proliferate through the genome; what you might call nature's failed experiments.

But, does nature, with the exception of some few, grotesque mutations, fail so broadly? Or is there some order in its success, or some careful equilibrium, or balance, to how species mutate and originate within an evolving biosphere? What does it even mean to ask this? What is a balanced, evolving, natural species? Does it require a biosphere that is itself as self-regulating as the earth appears? Or, as with James Lovelock's Gaia, are the two not mutually exclusive? Are the species that inhabit the earth, that evolve within it as vital to the evolution and the balance of the biosphere as the biosphere is to the balance and evolution of the species that inhabit it? Do the species evolve, from one kind of thing to another, because the biosphere itself evolves? Does the biosphere evolve because of the evolution of species? Here I mean both animal and plant (any living thing, for without living things the earth wouldn't be a biosphere). But I am also referring to the delicate balance of biochemicals necessarily for life; for example, the very atoms (carbon, nitrogen, oxygen, hydrogen, helium, etc.,) and the complex molecules comprised of these that make up the life-giving air and water that most everything needs to survive and flourish.