When we start out with a question in science, we need to break it down to its most fundamental components.
Let’s say we want to know the answer to “Do non-human animals have language?”. First we need to specify what is meant by language. Do we just mean verbal language, or are we including gestural languages like sign language? Do we want to know about all animals, or just the most intelligent ones like chimps or dolphins? Does the communication need grammar? And so on, and so forth.
For every question we answer, a thousand smaller questions crop up.
For this reason, scientific research tends to be very niche. A single study might attempt to answer one facet of one section of a broader question.
By doing this, we can learn more about that question in order to ask better questions. One day, when enough of the question has been answered, we find ourselves with a theory.