Thoughts on what I'm reading

I'm currently reading Krakatoa: The Day the World Exploded: August 27, 1883 (Harper, 2003) by Simon Winchester.  It's great, but something struck me as I was reading it, that speaks back to some issues I'd had with others and my own writing, specifically, how to deal with an audience with varying levels of knowledge in the subject you're discussing.  Winchester, originally trained as a geologist before becoming a journalist in the late 1960s, has to deal with this here.  Discussing the biodiversity and geology of Krakatoa necessitate a discussion of natural selection and plate tectonics.  The problem is that much of his audience will be well-versed in these subjects (i.e. the type of people who will actively seek out a book about Krakatoa) while many others will know little to nothing of the matter. So what do you do?  If you elide this information, you confuse the latter group, but if you go into detail, you bore the former.  Winchester manages to have his cake and eat it too.  What he does is couch the theory in anecdote, for example, explaining natural selection through the life and career of Alfred Russel Wallace.  While some points are necessarily dry (there's no other way to explain how a transform-fault functions than to just dive in) Winchester essentially manages to give the people who are already aware of the underlying theory something else to focus on while presenting the theory itself to those who don't know it.