This is the sixth installment of a series responding to John Timmer’s online review of the supplementary biology textbook Explore Evolution (EE). The first part is here, the second here, the third here, the fourth here, and the fifth here.

6. Timmer’s Double Standard on Textbook Treatments of Evolution
Timmer repeatedly attacks EE for allegedly trying to “divide and conquer” evolution because it discusses the different lines of scientific evidence (i.e. fossil, anatomical, molecular) regarding common descent in separate sections. Timmer’s criticism reveals either his gross ignorance of how contemporary biology texts cover evolution, or that he’s using a blatant double standard. EE was written to complement the coverage of evolution in standard biology textbooks, and so it follows the approach used by most biology textbooks, which divide the evidence for common descent into separate sections dealing with fossils, comparative anatomy, molecular biology, embryology, and biogeography. (See for example, Campbell, Reece, and Mitchell, 2003, pp. 260-263; Mader, 2007, pp. 224-227; Raven & Johnson, 2005, pp. 460-466.)

If Timmer wants to argue for a different way of presenting the evidence for evolution, fine. But he should acknowledge up front that most biology textbooks — not just Explore Evolution — fail to follow his preferences. Attacking EE simply because it follows the approach adopted by most biology textbooks is unreasonable.

The same can be said for Timmer’s criticism of EE for only discussing the fossil bird Archaeopteryx when covering the origin of flight. Timmer complains that “[n]one of the other fossils on either side of the transition to flight are deemed worthy of mention.” Disregarding the fact that Timmer himself fails to name any of these allegedly “worthy” transitional fossils in his critique, it must be noted that most high school textbooks (which EE is supposed to complement) also do not mention bird fossils beyond Archaeopteryx when discussing the evolution of flight. Miller & Levine’s 2008 edition of Biology has an entire section titled “Evolution of Birds,” but the only fossil species named is Archaeopteryx. Miller & Levine’s Biology asserts that “new fossils of ancient birds are being found all the time,” but much like Timmer, the textbook gives no names or specific examples of what those fossil species are.

So once again, Timmer holds Explore Evolution to a standard that he’s not willing to apply to other biology textbooks.

References Cited:
Neil A. Campbell, Jane B. Reece, Lawrence G. Mitchell, and Martha R. Taylor, Biology: Concepts and Connections, Benjamin Cummings, 4th Ed., 2003.

Holt Science & Technology, Life Science: California Edition, Holt Rinehart and Winston, 2001.

Sylvia S. Mader, Essentials of Biology, McGraw Hill, 2007.

Kenneth R. Miller & Joseph Levine¸ Biology, Prentice Hall, 2008.

Peter H. Raven, George B. Johnson, Jonathan B. Losos, Susan R. Singer, Biology, McGraw Hill, 7th Ed., 2005.