As I try to write my thesis, I am coming to a realization. Writing complex scientific chains of thought in a way that is both clear and interesting is hard. Much harder than the natural history writing I have much more experience with. One of the many reasons this is so is because scientific writing must rely almost entirely on sentence meaning rather than speaker meaning. My wife, a linguist, has helped me to appreciate the difference. Sentence meaning is the information actually contained in the words of the sentence, accessible without knowledge of the thought processes or social context of the speaker. If a young man says, "Oh, I hate spiders!" the sentence meaning is simply, "I hate spiders." However, if the young man has just been asked to help clean out a garage, walks into the garage, looks around, then turns to the person who asked for his help and says, "Oh, I hate spiders!" much more is conveyed. The young man is not just signaling his dislike of spiders, but also that he has detected spiders in the garage, and is therefore reluctant to help with the cleaning. He may even be conveying that while he doesn't want to help he is a friendly person and therefore is reluctant to refuse outright, but please take this hint. This additional information, the speaker meaning, is nowhere in the text of his words, but is obvious to most humans who have healthy social comprehension skills. Much of the artistry of writing is in the careful crafting of speaker meaning. Beautiful writing, poetry in particular, generally conveys far more through speaker meaning than sentence meaning. But scientific writing by tradition and necessity relies almost entirely on sentence meaning. If any piece of information or logic is a necessary part of a scientific argument, the author has little choice but to state it outright. Likewise, if something has not been stated, scientific authors generally cannot assume the reader knows or agrees with it. This of course goes only so far. Scientists, as humans using human languages, are incapable of avoiding speaker meaning entirely. But the injunction is clear: thou shalt not ask thine audience to read between the lines.
Writing a complex chain of mathematics laced evolutionary thought in a way that is readable and elegant is a real challenge. I begin to understand why so many scientists over the centuries have largely let elegance and readability fall by the wayside. I very much hope to avoid following that clearly but unattractively marked trail.