The direction is in the population.<quoted text>
In hindsight yes, in foresight no. There are so many positive paths that evolution can take it is hard to predict what will happen ahead of time. There are some very narrow aspects that can be predicted, but even then the exact path cannot be specified. Look at sight as an example. It has evolved many times and taken many different paths. The end result is roughly the same, but the mechanics are different due to the different paths.
The environment drags the population toward greater fitness within it. The population exists in an environment containing life-threatening hazards that can destroy individuals in the population. Because there are variations among the individuals, some are better able to resist the hazards and survive, and others are more vulnerable and are destroyed.
By destroying the more vulnerable members, the environment inadvertently leaves behind the individuals who were best able to resist destruction (the survivors). Those will be the parents of the next generation, and the next generation will tend to have characteristics similar to their parents, i.e. the characteristics of the survivors.
The variation among individuals is random, without direction. Then the environment destroys the ones who are less well suited to surviving in that environment, which gives a direction to the population's evolution by only allowing changes in one direction to be successful.
That is the direction of evolution.