Topic trails in an article on BSE

This article on BSE has several topics interwoven through it: animals, disease, research, food. There is much reporting. And it contains hypothetical language and hedging in abundance. I am coining the term Topic Trail since lexical chain and string are both taken: a topic trail is a set of words that represents a topic that runs through a text. Like every worthy forest, there is more than one trail in a text. This is my afflatus of May 28th 2012.

The article as it was originally published (2002) can be found here. The author of this article, Deborah MacKenzie passed away in 2012. See her obituary.

Topic Trails are best represented by colour-coding words and phrases in the text itself: each colour represents a trail. This illustrates the trails in a way that lists and mindmaps (spray diagrams) cannot. See an example from a Guardian review of Amour.