Here are some analogies between the evolution of biological species and the evolution of language. Like all analogies, these are not precise, but merely suggestive and therefore interesting.
A few generations ago, “gay” meant “lighthearted and carefree.” Now it clearly and mainly means a homosexual man. It still bears the first meaning technically, but virtually no one uses it this way any longer. The “natural selection” analogue here is that the word “gay” for homosexual men got “selected” because it was catchy and positive and memorable, and so it caught on.
“Enormity” means “vast evil.” But somehow over the last several decades it has come to be synonymous with “enormousness,” which means something that is very large. I am inclined to deplore the loss of the distinction between the two words, but then I remind myself that language is always changing. If enormity comes to displace enormousness in meaning, some other word will evolve to mean “vast evil.”
In biology, genetic drift is the concept that some alleles go to fixation not because of selection, but purely by accident. In this language analogy, I see no popular selection pressure for “enormity” to displace “enormousness”; it’s pure sloppy happenstance, though of course also because the words sound alike.
Word: Niggard, or niggardly
Niggard or niggardly bear no relation at all to the N word. Yet the word, already a bit arcane, has been protested as suggesting
the N word. Thus it is being driven from the gene pool of words by negative selection, also known as purifying selection, in which deleterious alleles are purged.
Bluetiful is a word recently invented by Crayola for a new shade of blue crayon. It has descended from the word species “blue” and “beautiful.” It represents a language speciation event, the arising of a new word “species” from ancestral word species.
Interestingly, the word provoked an outcry from language authoritarians like Vegdipshit,
who lamented how making up a non-existent word was likely to confuse and even traumatize our poor little chirren, at whom crayons are aimed. These idiots fail to realize that language is changing all the time, and indeed there are at last two words that describe the inventing of a word like bluetiful: “neologism” and “portmanteau.”
Far from being a source of confusion for kids, the new word “bluetiful” can be used as a teaching moment, to explain to kids the elasticity and plasticity of language, and how like biological species language "species" are ever evolving for reasons quite similar to natural selection, genetic drift, purifying selection and speciation.
There are tons of words that exist in standard dictionaries today that did not exist 50 years ago. I could well imagine the word “bluetiful” evolving to mean, not just a pretty shade of crayon, but something like, “someone who is sublime in their sadness.” But who knows? That could happen, but if it does, it won’t be a goal of word evolution, but nor will it be random.
But then, I am an “illiterate Yank” so what do I know, right?