Well, that’s one way of looking at it.
From New Scientist:
Some thought it was impossible. But a population of stickleback fish that breed in the same streams is splitting into two separate species before our eyes, and at rapid speeds.
Three-spine sticklebacks were introduced to Lake Constance in Switzerland around 150 years ago – a blink of an eye in evolutionary terms. But since then, the fish have begun splitting into two separate types: one that lives in the main lake (pictured above left, female top, male in breeding colours below), and another that lives in the streams that flow into it (above right).
The main lake dwellers are bigger, with longer spines and tougher armour. In theory, these differences could be due to lifestyle rather than evolution – perhaps lake fish survive longer and grow larger.
But David Marques of the University of Bern and colleagues have found that there are already clear genetic differences between the two types. “We could be glimpsing the beginnings of two species,” he says. More.
Hey, wait a minute. When humans were “speeding up evolution” yesterday, the story was that the threespine sticklebacks under study had gone from two species to one through hybridization:
If the hybridization happened so quickly (resulting in two “extinctions”), what justifies the fish being classified as separate species before? When one asks this question, one is always told that all evolutionary biologists recognize the problem, but never that anyone proposes to do anything about it. After a while, that makes communication difficult. And raises suspicious about the reason the problem is allowed to just go on (because it greatly reduces the evidence bar for these kinds of claims?).
One might reasonably conclude the same thing here. It seems as if, as long as someone decided the fish were separate species, however they decided it, others are justified in making claims about extinction and speciation.
But have we really established that anything much is happening at all? Isn’t this just another episode in the long-running Darwin’s finches’ beak series (where it turned out, after an avalanche of publicity, that speciation wasn’t really happening, just hybridization)?
No wonder there is no incentive to change the system! Talk about a paper mill.
See also: Other examples of hybridization
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The stickleback is in any event an interesting fish: