Yep, that's the one I was going to say :-) "It goes really deep" is, unfortunately, a relative description. Half-way through my undergraduate studies, I had pretty much outgrown it and needed more specialized books. Nonetheless, it is a superb entry-level college textbook that covers the entire breadth of modern biology. The text is very understandable and gives more background information than is needed for a typical introductory lecture to any given topic (while still emphasizing the salient points so you don't get confused). Apart from the above-mentionend interviews, it also includes sections on current methods in biology, which are pretty handy when you're new to the field. Plus, the illustrations are simply excellent: pretty to look at and a huge help for understanding. On the whole, I find it to be one of the most aesthetically pleasing textbooks I know. (Beaten only by Futuyma's "Evolution".) My best investment in university so far!
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