Freaks of Nature: What Anomalies Tell Us About Development and Evolution

When, in Freaks (1932), the legless Johnny Eck lifts up onto his hands and walks around on them, it's not just a display of grace and perseverance. In Freaks of Nature: What Anomalies Tell Us About Development and Evolution, Mark S. Blumberg suggests that Eck also reminds us that there's nothing "natural" about normal behavior. We each develop and adapt to the world in the body that we've been given — the culmination of eons of evolution, as Neil Shubin describes in Your Inner Fish: A Journey Into the 3.5-Billion-Year History of the Human Body.

These different perspectives on embodiment in time — we learn to inhabit our bodies as we grow and develop; our bodies are, in some sense, quite ancient — both arise from a recent turn in evolutionary biology whereby scientists increasingly argue for more integrative views on genetics and epigenetics (the study of how genes are expressed). Paleontologists have found startling new tales to tell about the implications for human evolution of ancient fossilized structures. The reason the muscle around men's intestinal walls is like so much wet Kleenex, for example, has to do with our fishy ancestors — fish gonads are close to their heart and the long journey from the heart to the pelvis weakened the surrounding muscles. Meanwhile, developmental perspectives remind us that not all behavior is predetermined, but that variation in structure is affected by the legacy of evolution.

In a September interview, Blumberg said that one of the best reasons to write popular science books is that the process forces him to think more clearly about the assumptions in his research: "The challenge is how to tell the story as narrative...without losing the details of the science or altering the underlying conceptual information." He claims that working in this mode "has created a nice feedback loop" by forcing him to first articulate his principles. Blumberg further notes that having scientists — even scientists of quite different theoretical interests — state their cases plainly in public invites the very disagreement that makes evolution a science, rather than a shibboleth such as intelligent design or creationism. Blumberg is a developmental psychobiologist, and thus advocates for a more supple understanding of the interplay between development, behavior, and evolution than has usually been accepted. He eloquently defends the view that "development is the story of adaptation within one lifetime," and that thinking seriously about anomalies helps us see "how much adaptability there is in the developing organism."

In contrast to Blumberg's somewhat polemical goals, Shubin, a paleontologist attached to the Field Museum and the University of Chicago's medical school, is eager to explain the recent convergent threads in evolutionary sciences, as genetics, molecular biology, paleontology, and numerous other disciplines feed into one another. In a nod to Darwin's conclusion of The Origin of Species, he relates a story about going to a museum with his son, and being overwhelmed with emotion at seeing the Apollo 8 command module. Shubin describes being awestruck by the glory of nature and at science's extraordinary ability to make sense of it.

Shubin writes with clarity, but also maintains a humane sense of limits. Natural selection is ingenious, but it must always be remembered that our bodies are profound kludges — one hacked-together solution after another. Sometimes these are elegant, but the solutions always involve a compromise between a structure's current needs and its evolutionary heritage. Shubin's story is not only one of scientific explanation, but also an account of his own training as a scientist. He is, at all times, both funny and evocative, making Your Inner Fish worthwhile reading for any interest level.

Of course, these two books can't undo a debased understanding of evolution all alone. But by engaging us in stories about the most enigmatic aspects of our bodies, Blumberg and Shubin remind us why we should care, while also offering a visceral kick of new knowledge. -Jason B. Jones