This might be a strangely framed question for a liguist, since I'm a physicist and know very little about this field.
My question relates to how changing a symbol (for example a letter) in a word changes its meaning. For example, in English the word "CAT" means something completely different if we "mutate" one letter. Even if RAT, CUT and CAR are one letter appart from CAT the meaning is far away from the original. I picture this mathematically like a function (which converts symbols into meaning) that in the case of English should be a discontinuous or jagged function.
I was asking myself if there is a human language that continuously transforms symbols into meaning. That is, a language that when a small random change is performed over a word the meaning suffers a continuous small change.
Maybe it sounds weird but a non-human language like DNA has this property. If you change one nucleobase the change in the phenotype is not very large. If it were very large, then natural selection wouldn't work, since any small mutation would give drastic changes and gross deformities that wouldn't make for any stable correlation between the environment and the fitness to it. So my question is, are there any human languages with that property? And does this feature has a proper name in the field of linguistics?
Perhaps one could say that there is a small subset of "continuous morphology" (let's call it like that, for now) in many languages, since there are things like prefixes and sufixes that mantain some of the abstract meaning between different words, while mantaining morphological similarities (since the prefix or sufix is the same configuration of letters)?
Are there entire languages like this or large subsets of a language that behave in this way?