Another random book meme

So, after posting the last book meme, Mike went and published another book meme. Here's how it goes:

1. Pick up the nearest book (of at least 123 pages).

2. Open the book to page 123.

3. Find the fifth sentence.

4. Post the next three sentences.

In my case, the closest book was Endless Forms Most Beautiful by Sean B. Carroll. And here's your three sentences:

For example, even though the seven stripes of some tool kit patterns appear very similar and evenly spaced, each stripe is drawn by a different switch that integrates different combinations of longitudinal inputs. This seemed at first like an awful lot of machinery for making just one pattern. But this stripe-by-stripe construction of striped patterns in the fly embryo was the first clue to the general rule that the whole expression pattern of any tool kit gene is actually the sum of many parts, with individual parts controlled by individual switches.

And there you have it: a turning point in Evo Devo. The book is actually quite a good summary of recent developments in biology. The last chapter is probably one of the best defenses of science and evolution that I've read recently.