One of the best ways to appreciate not only how long life has had to evolve, but also how short the period has been since “modern life” (aka birds, mammals, and humans) arose is to look at an evolutionary “timeline” that is drawn to scale. In the footnotes of WEIT I direct readers to one of these, but I have since found a much better one on the Web. It was constructed by John Kyrk, and is seen here. It’s a great teaching tool, with nice graphics, including eight telescoping timelines, each one a small piece of the previous one.