If we are to examine the idea of choice then we should begin by defining our terms. I will define choice in the mathematical sense according to the axiom of choice. The actual statement of the axiom is a bit technical and requires infinity so we can content ourselves with the following: choice is defined as the ability to select one item from a set of indistinguishable items. Distinguishability has important implications in mathematics, thermodynamics, and quantum mechanics so it is reasonable to include it in our definition. If the items are distinguishable, then selecting one is a trivial matter as some factor will favor one choice over the others. It is only when the choices are identical that we truly “choose.”
Philosophers may debate whether choice as such exists or does not, but we may also ask a practical question about how this ability might arise. For this purpose, let us assume that humans do possess the ability to choose and that most other species do not (or at least not at our level). It would necessarily have evolved and therefore be of enough benefit to survival to warrant the extreme cost of the human brain. As it must have evolved before the advent of agriculture, it would be beneficial in the hunter-gatherer lifestyle. When hunting, selecting the weakest, or fattest, or most desirable is a fairly simple application of the decision-making power which weighs information and finds the optimum. If a unique optimum can be found then there is no need for choice. Distinguishability on the basis of some optimizable factor is the difference between a choice and a decision.
Before we proceed I should describe a defensive behavior of prey animals called flocking. There are many benefits to travelling in a large group, especially for protection. One non-obvious benefit is that predators are presented with the opportunity to kill one of many. This is known as the predator confusion effect. The effect can be heightened if all the individuals look and act identically (flocking behavior). A good example is the zebra whose stripes make a lone zebra highly visible, but make herds of zebras a mass of shifting lines stopping a predator from focusing on a target long enough to kill it. In systems where predator confusion is in effect, prey can be singled out for greatly increased risk by marking them as different using colored dye. How might hunters counter this strategy of indistinguishability? If choice is an ability specifically evolved, and not some freak accident of nature, then I think it possible that it is a counter-strategy to flocking behavior in our prey.
It is sometimes said that when presented with many similar options, choice is paralyzing, but in fact the opposite is true; choice is what allows us to select an option despite it not differing from its fellows in any way. The paralysis comes from attempting to make a decision among distinguishable objects without enough information to definitively know which is optimal. I have had much success with clarifying the difference between choices and decisions to friends asking about selecting colleges, careers, romantic partners, etc. When they accept that it is impossible to decide what is “best,” they are free to make an arbitrary choice and continue with their life.