Your Inner Fish: A Journey Into the 3.5-Billion-Year History of the Human Body (33 page)

The transformation of the hyomandibula into the stapes is reviewed in comprehensive book-length treatments of the evolution of primitive fish or the origin of land-living animals: J. Clack,
Gaining Ground
(Bloomington: Indiana University Press, 2002); P. Janvier,
Early Vertebrates
(Oxford, Eng.: Oxford University Press, 1996). It is also discussed in recent research papers, including Clack, J. A. (1989) Discovery of the earliest known tetrapod stapes,
Nature
342:425–427; Brazeau, M., and Ahlberg, P. (2005) Tetrapod-like middle ear architecture in a Devonian fish,
Nature
439:318–321.

The origin of the mammalian middle ear is discussed from the perspective of a scientific historian in P. Bowler,
Life’s Spendid Journey
(Chicago: University of Chicago Press, 1996). Key primary sources include: Reichert, C. (1837) Uber die Visceralbogen der Wirbeltiere im allgemeinen und deren Metamorphosen bei den Vogeln und Saugetieren,
Arch. Anat. Physiol. Wiss. Med.
1837:120–222; Gaupp, E. (1911) Beiträge zur Kenntnis des Unterkiefers der Wirbeltiere I. Der Processus anterior (Folii) des Hammers der Sauger und das Goniale der Nichtsäuger,
Anatomischer Anzeiger
39:97–135; Gaupp, E. (1911) Beiträge zur Kenntnis des Unterkiefers der Wirbeltiere II. Die Zusammensetzung des Unterkiefers der Quadrupeden,
Anatomischer Anzeiger,
39:433–473; Gaupp, E. (1911) Beiträge zur Kenntnis des Unterkiefers der Wirbeltiere III. Das Probleme der Entstehung eines “sekundären” Kiefergelenkes bei den Säugern,
Anatomischer Anzeiger,
39:609–666; Gregory, W. K. (1913) Critique of recent work on the morphology of the vertebrate skull, especially in relation to the origin of mammals,
Journal of Morphology
24:1–42.

Major literature on the origin of the mammalian jaw, chewing, and the three-boned middle ear includes Crompton, A. W. (1963) The evolution of the mammalian jaw,
Evolution
17:431–439; Crompton, A. W., and Parker, P. (1978) Evolution of the mammalian masticatory apparatus,
American Scientist
66:192–201; Hopson, J. (1966) The origin of the mammalian middle ear,
American Zoologist
6:437–450; Allin, E. (1975) Evolution of the mammalian ear,
Journal of Morphology
147:403–438.

The evolutionary origin of
Pax 2
and
Pax 6
and the evolutionary link of ears and eyes to box jellyfish is discussed in Piatigorsky, J., and Kozmik, Z. (2004) Cubozoan jellyfish: an evo/devo model for eyes and other sensory systems,
International Journal for Developmental Biology
48:719–729.

Links of sensory receptor molecules to different molecules in bacteria are discussed in Kung, C. (2005) A possible unifying principle for mechanosensation,
Nature
436:647–654.

CHAPTER ELEVEN THE MEANING OF IT ALL

The methods of phylogenetic systematics are discussed in a number of sources. Key primary literature includes the classic work of Willi Hennig, published originally in German (
Grundzüge einer Theorie der phylogenetischen Systematik
[Berlin: Deutscher Zentralverlag, 1950]) and translated into English more than a decade later (
Phylogenetic Systematics,
trans. D. D. Davis and R. Zangerl [Urbana: University of Illinois Press, 1966]).

Methods of phylogenetic reconstruction, which form the basis for the chapter, are discussed in detail in P. Forey, ed.,
Cladistics: A Practical Course in Systematics
(Oxford, Eng.: Clarendon Press, 1992); D. Hillis, C. Moritz, and B. Mable, eds.,
Molecular Systematics
(Sunderland, Mass.: Sinauer Associates, 1996); R. DeSalle, G. Girbet, and W. Wheeler,
Molecular Systematics and Evolution: Theory and Practice
(Basel: BirkhauserVerlag, 2002).

A comprehensive treatment of the phenomenon of independent evolution of similar features is in M. Sanderson and L. Hufford,
Homoplasy: The Recurrence of Similarity in Evolution
(San Diego: Academic Press, 1996).

To see the tree of life and the different hypotheses for the relationships between living creatures, visit http://tolweb.org/tree/.

The notion that our evolutionary history has medical implications has been the subject of several good recent books. For comprehensive and well-referenced treatments, see N. Boaz,
Evolving Health: The Origins of Illness and How the Modern World Is Making Us Sick
(New York: Wiley, 2002); D. Mindell,
The Evolving World: Evolution in Everyday Life
(Cambridge, Mass.: Harvard University Press, 2006); R. M. Nesse and G. C. Williams,
Why We Get Sick: The New Science of Darwinian Medicine
(New York: Vintage, 1996); W. R. Trevathan, E. O. Smith, and J. J. McKenna,
Evolutionary Medicine
(New York: Oxford University Press, 1999).

The apnea example I derived from discussions with Nino Ramirez, chairman of the Department of Anatomy at the University of Chicago. The hiccup example is derived from Straus, C., et al. (2003) A phylogenetic hypothesis for the origin of hiccoughs,
Bioessays
25:182–188. The human-bacterial gene switch used in the study of mitochondrial cardioencephalomyopathy was originally discussed in Lucioli, S., et al. (2006) Introducing a novel human mtDNA mutation into the
Paracoccus denitriticans
COX 1 gene explains functional deficits in a patient,
Neurogenetics
7:51–57.

ONLINE RESOURCES

A number of websites and blogs carry accurate information and are updated frequently.

http://www.ucmp.berkeley.edu/ Produced by the Museum of Paleontology at the University of California–Berkeley, this is one of the best online resources on paleontology and evolution. It is continuously updated and revised.

http://www.scienceblogs.com/loom/ This is Carl Zimmer’s blog, a well-written, timely, and thoughtful source of information and discussion on evolution.

http://www.scienceblogs.com/pharyngula/ P. Z. Myers, a professor of developmental biology, writes this accessible, informative, and cutting-edge blog. This is a rich source of information, well worth following.

Both Zimmer’s and Myers’s blogs are at http://www.scienceblogs.com, a site that contains a number of excellent blogs also worth following for information and commentary on recent discoveries. Blogs relevant to the theme of this book at that site include Afarensis, Tetrapod Zoology, Evolving Thoughts, and Gene Expression.

http://www.tolweb.org/tree/ The Tree of Life Project provides a regularly updated and authoritative treatment of the relationships among all groups of life. Like the UCMP page at Berkeley, it also includes resources for learning about how evolutionary trees are made and interpreted.

ACKNOWLEDGMENTS

All the illustrations, except where noted, are by Ms. Kalliopi Monoyios (www.kalliopimonoyios.com). Kapi read drafts of the manuscript and not only improved the text but designed art that matched it. I have been truly fortunate to work with someone with so many talents. Scott Rawlins (Arcadia University) generously gave permission to use his elegant rendering of
Sauripterus
in Chapter 2. Ted Daeschler (Academy of Natural Sciences of Philadelphia) graciously provided his superb photos of the great
Tiktaalik
“C” specimen. Thanks are due to Phillip Donoghue (University of Bristol) and Mark Purnell (University of Leicester) for permission to use their rendering of the conodont tooth array, McGraw-Hill for permission to use the textbook figure that started the hunt for
Tiktaalik,
and Steven Campana of the Canadian Shark Research Laboratory for the photos of shark organs.

One of the greatest debts students of anatomy have is to the people who donate their bodies so that we can learn. It is a rare privilege to learn from a real body. Sitting through long hours in the lab, one feels a very profound connection to the donors who make the experience possible. I felt that connection again while writing this book.

The ideas I present here are rooted in research I’ve done and in classes I’ve taught. Colleagues and students too numerous to name—undergraduates, medical students, and graduate students—have played a role in the thinking that went into these pages.

I owe a great debt to the colleagues I have worked with over the years. Ted Daeschler, Farish A. Jenkins, Jr., Fred Mullison, Paul Olsen, William Amaral, Jason Downs, and Chuck Schaff have all been part of the stories I tell here. Without these people I would have had no reservoir of experience on which to draw, nor would I have had as much fun along the way. Members of my laboratory at the University of Chicago—Randall Dahn, Marcus Davis, Adam Franssen, Andrew Gillis, Christian Kammerer, Kalliopi Monoyios, and Becky Shearman—all influenced my thinking and tolerated my time away from the bench as I wrote.

Colleagues who gave their time to provide needed background or comments on the manuscript include Kamla Ahluwalia, Sean Carroll, Michael Coates, Randall Dahn, Marcus Davis, Anna DiRienzo, Andrew Gillis, Lance Grande, Elizabeth Grove, Nicholas Hatsopoulos, Robert Ho, Betty Katsaros, Michael LaBarbera, Chris Lowe, Daniel Margoliash, Kalliopi Monoyios, Jonathan Pritchard, Vicky Prince, Cliff Ragsdale, Nino Ramirez, Callum Ross, Avi Stopper, Cliff Tabin, and John Zeller. Haytham Abu-Zayd helped with many administrative matters. My own teachers of anatomy in the Harvard–MIT Health Sciences and Technology program, Farish A. Jenkins, Jr., and Lee Gehrke, stimulated an interest that has lasted over twenty years.

Key advice at the inception of the project, and inspiration throughout, came from Sean Carroll and Carl Zimmer.

The Wellfleet Public Library (Wellfleet, Massachusetts) provided a comfortable home, and much-needed retreat, where I wrote significant parts of the book. A brief stint at the American Academy in Berlin put me in an environment that proved critical when I was completing the manuscript.

My two bosses, Dr. James Madara, M.D. (CEO, University of Chicago Medical Center, Vice President for Medical Affairs, Dean and Sara and Harold Thompson Distinguished Service Professor in the Biological Sciences Division and the Pritzker School of Medicine), and John McCarter, Jr. (CEO, The Field Museum), supported this project and the research behind it. It has been a true pleasure to work with such insightful and compassionate leaders.

I have been fortunate to teach at the University of Chicago and to have had the opportunity to interact with the leadership of the Pritzker School of Medicine there. The deans, Holly Humphrey and Halina Bruckner, graciously welcomed a paleontologist to their team. Through interacting with them I came to appreciate the challenges and importance of basic medical education.

It has been a great pleasure to be associated with The Field Museum in Chicago, where I have had the opportunity to work with a unique group of people dedicated to scientific discovery, application, and outreach. These colleagues include Elizabeth Babcock, Joseph Brennan, Sheila Cawley, Jim Croft, Lance Grande, Melissa Hilton, Ed Horner, Debra Moskovits, Laura Sadler, Sean VanDerziel, and Diane White. I am also grateful for the support, guidance, and encouragement I have received from the leaders of the Committee on Science of the Board of Trustees at The Field Museum, James L. Alexander and Adele S. Simmons.

I am indebted to my agent, Katinka Matson, for helping me turn an idea into a proposal and for advice throughout the process. I feel privileged to have worked with Marty Asher, my editor. Like a patient teacher, he gave me a nurturing combination of advice, time, and encouragement to help me find my way. Zachary Wagman contributed to this project in countless ways by being free with his time, keen editorial eye, and good counsel. Dan Frank made insightful suggestions that stimulated me to think about the story in new ways. Jolanta Benal copyedited the text and improved the presentation immeasurably. I am very grateful to Ellen Feldman, Kristen Bearse, and the production team for their hard work under a tight schedule.

My parents, Gloria and Seymour Shubin, always knew that I would write a book, even before I did. Without their faith in me, I doubt that I ever would have put a word on paper.

My wife, Michele Seidl, and our children, Nathaniel and Hannah, have been living with fish—both
Tiktaalik
and this book—for the better part of two years. Michele read and commented on every draft of this text and supported long weekend absences while I wrote. Her patience and love made it all possible.

Copyright © 2008 by Neil Shubin