No, the correct way to phrase it is "survival of the fit". It's very common for limiting factors (water, calories, vitamins, etc) to have a plateau. In the range from starvation to 'enough', more ability to find food is an advantage. In the range from 'enough' to 'excess', there's no payoff. So what evolution creates is a population of surviving individuals who are each 'enough' on all their success parameters, but who embody a diverse range of ways to be 'fit'. This diversity then allows the species to handle change that leaves part of the population 'unfit'.
Very rarely, is there an absolute competition where the 'fittest' survive. That would actually drag down evolution - it would create genetic bottlenecks.
Yeah, my issue wasn't with the mechanism of evolution, more with the phrasing. The word "survive" implies some sort of agency, the inverted phrasing does not. I could alter it to "decline of the weakest attributes as they are less successful and thus less likely to breed and pass their genetics on", but that's quite a mouthful for a tagline to teach schoolkids! ;)
PS: And yes I know there are plenty of situations where even "weak" attributes won't necessarily get weeded out, but then you'd be extending the tagline quite a bit!
Except, a stable population (not currently coping with a change from their evolved circumstances) doesn't really contain "weak" individuals beyond the normal lossage to infection, harmful mutation, violence and old age.
It may well contain groups that biologists project human cultural ideas on and call weak. But the continued presence of those groups shows them to be a useful part of the species diversity.
(I strongly recommend "The Genial Gene" and "Evolution's Rainbow", both by Joan Roughgarden, for further reading.)
Very rarely, is there an absolute competition where the 'fittest' survive. That would actually drag down evolution - it would create genetic bottlenecks.