Its not unusual that a portion of a population deviates from common norms and expectations. This is true for animals, (humans) and plants alike.

In many cases deviations can be explained as a being caused by natural genetic mutations that are also the driving factor behind evolution. Of course only a minor subset of mutation is actually advantageous enough to have a chance of eventually being present within the majority.

There is no need to act like its weird or special. Its just natura and it can be predicted with statics.