Thus the BBC (who are often the perpetrators) served up a good one today in a story on 'bird funerals'. Apparently, when Western scrub jays discover the dead body of one of their kind, they fly down and gather round it.
And then comes the 'bad evolution' bit: "The behaviour may have evolved to warn other birds of nearby danger, report researchers in California, who have published the findings in the journal Animal Behaviour."
The problem is, of course, the word "to", as in "The behaviour may have evolved to warn other birds", because in the 'standard theory' there is no 'to' or 'so that'.
The 'standard theory' of evolution, as I understand it, is that a fresh characteristic - in this case a particular behaviour - conveys a significant breeding advantage in those organisms possessing that new characteristic, which means that more of them come to exist over time.
So we could say, "When this behaviour emerged amongst jays it may have resulted in a greater breeding opportunity for those bird populations in which it warned others of nearby danger and allowed them to out-breed those populations which did not possess this characteristic." Not nearly as succinct as 'to', but not as misleading either.
Of course we also have to presume that this was a population phenomenon, because the birds 'being warned' are not necessarily the same as those doing the warning, and I can see how the former might have gained a breeding advantage, but I wonder about the latter. In fact, I would have thought flocking round a dead body, if the death was the result of disease or predatory action, was likely to mitigate against more breeding opportunities, since you were more likely to become infected or get eaten. But presumably it must have worked something like what is being suggested. (Or maybe 'compassionate' birds were perceived as the sensitive kind and could more easily get mates -- who knows?)
Incidentally, I think I am right in saying that 'survival' per se can never be an evolutionary driver, since it merely means you stay the same but don't get eaten, starved, drowned, fried or whatever. It is not 'survival' that produces change, but a fresh 'advantage', which must also be a 'significant' advantage in the sense that you actually breed more so as to pass on the new characteristic.
This is why the 'gradual change' scenario has to be nuanced. It is all very well saying that the eye, for example, could evolve by numerous small steps, but each small step still has to be big enough to convey an actual breeding advantage.
The definition of 'how small' an 'evolutionary' change needs to be is not 'small enough to be different from the previous form of the eye' but 'big enough that the organism with the new form is better equipped than its parents and cousins to the extent that it breeds more'. Remember, we are talking about 'natural selection', and the natural selection must be not what survives but what excels. At least, that is what I've understood.
Please give a full name and location when posting. Comments without this information may be deleted. Recommend: