I think his argument is that it is not an active, involved process. It's self-selection of life that is capable of producing off-spring, or is successful enough to attract mates, or is in some form lucky enough. It's not something the individual species thinks about, or encourages through some special brain-power, such as: "hmmm, I can't do this very well. Well, time to kill off the ol' eyes and develop new senses! huzzah, I'm a super-fish ladies, mate with me!" Adaptation and evolution just happen. When it's slowly forced due to decreasing odds of survival as a species currently exists, the ones born with a genetic ability to handle it are likely to attract mates. It's life un-consciously selecting for desirable traits. In nature, the winners attract the mates: the one who can provide more for their clan, the one who can defend the clan more, the one who can feed himself more easily, etc. The one with the longer eye-stalk may or may not get lucky. That longer eye stalk may have no benefit, and yet if it doesn't increase chances of death, it might also survive generations and simply produce a new species or sub-species. It's entirely random and very odd how it all can go down. But back to the point: it's not an active, thought-about process. The species undergoing the "adaptation" or "evolutionary changes" is likely not even aware of the choices they make in mating, animals just like the look of apparent success, or potential success. They want a winner in their mate.