If a new trait increases the likelihood of the host passing on its genes to descendants, it will likely spread-though the mutated host could get eaten before ever having any offspring. But luck or not, if the new trait hampers the host's chances of surviving, it will not spread. Second, a genetic accident that creates new qualities xx and yy, which enhance the probability of survival may also create qualities aa and bb that have few implications for survival in the current environment but could become important in another environment. Many human mental capacities were not selected because they would allow humans to master math, physics, or engineering as these were irrelevant capacities in the environment in which these traits were selected. Now consider technologies.
Someone invents a new way of doing something.
If the new technology is useful enough to people who have the means to implement it, it will become commonplace. If it is practically useless or if it is useful only to people who have no means to implement it, it will likely disappear. All these unsupported technologies have been invented and some prototyped, but they haven't succeeded in our economic environment because they were not advantageous to those who decided their fate. They didn't fit in the environment of capitalism or in the environment of centrally planned systems, for that matter. No technology evolves and spreads unless there are people who benefit from it and have sufficient means to disseminate it.