Enjoy that tuna-fish sandwich while you can.

The Evolution Of Bad Tasting Tuna By Natural Selection.
As Postulated By Charles Darwin.

There is a premium commercial brand of tuna that for many years has striven for excellence in its product. Though this would seem the proper thing to do, the long term effect can, (I hope to show), be disastrous to the entire tuna industry, not to mention the enjoyment of many a lunch hour.

Of all the tuna in the sea, one individual tuna in particular is constantly rejected by the fishermen of Star-kist, that sole fish, ("sole fish" get it? Ha ha ha) being the one called "Charlie the Tuna", a character of impeccable culture and good taste, (or, at least he tries). The reason for his rejection has been, and remains, the fact that,

Star-kist doesn't want tuna with good taste, star-kist wants tuna that tastes good.

Being a tuna that tastes bad gives Charlie a great natural selection advantage over all his fellow tuna, assuming of course that he can get over his insane desire to be a Star-kist tuna. (He doesn't seem to realize the requirements of the job.)

How, having a single fish who tastes bad, can effect the tuna industry can best be demonstrated by plotting a gene pool through successive generations.

The diagram (left) is a tuna gene pool, (tuna can't swim in a gene pool.) this gene pool comprises all tuna genes from the entire world wide population of tuna. Shown off to the left in the gene pool is Charlie the Tuna's bad taste gene. (obviously not to scale.)

This one gene, governing how one tuna is going to taste doesn't really make a big difference, unless of coarse Charlie has a family.

The mathematics of inheritance discovered by Greggor Mendal in the 19th century, dictate that half of Charlie's offspring will carry the bad taste gene.

With the mortality of the tuna fishing industry's yearly decimation of the world wide tuna population, it is Charlie's bad tasting offspring that will fare better than normal good tasting tuna.
We know this to be so, because......

Star-kist doesn't want tuna with good taste, Star-kist wants tuna that tastes good.

So the ratio of mortality of Charlie's first generation will be lower than the average tuna's mortality. And that must be shown in our gene pool diagram. By expanding the ratio of tuna with bad taste and good tasting tuna.

So now the bad taste gene area has enlarged within the gene pool . This occurs because the bad taste gene has allowed a greater percentage of Charlie the Tuna's first generation of offspring to survive the fishing season, as compared to the percentage of the offspring of normal good tasting tuna.

The rate of this propagation of the bad taste gene throughout the gene pool will increase with each new generation. And as long as ...

Star-kist doesn't want tuna with good taste, Star-kist wants tuna that tastes good.

The generational expansion will continue to infiltrate the gene pool until the good tasting tuna that we now love is thinned out to the point of extinction.

When inbreeding occurs, (talk about bad taste), and two of Charlie the Tuna's prodigy, both of whom carry the bad taste gene, mate and produce offspring, then as before, half the fry will carry Charlie's bad taste gene, but now one quarter of the fry will be born with not only the fathers bad taste gene, but also the mothers bad taste gene. This "Tuna of the future" (with redundant bad tasting genes) will, no doubt, taste very bad indeed . And as before the genes of this very bad tasting tuna will propagate through the gene pool and eventually all tuna in the sea will carry Charlie's single or double bad taste gene.
since they will be the desentants of a single tuna , who, though he may not taste good, has tried to have good taste.

This is the evolutionary end result of that single and seemingly insignificant mutation that occurred when Charlie the Tuna was born, due to the pressure of natural selection , because...

Star-kist doesn't want tuna with good taste, Star-kist wants tuna that tastes good.