Children of the Ice Age : How a Global Catastrophe Allowed Humans to Evolve

Steven M. Stanley
Children of the Ice Age :
How a Global Catastrophe Allowed Humans to Evolve

"many of our actions degrade our habitat because we undertake them in order to reach goals whose allure blinds us to myriad dire consequences. The impact of human civilization on the earth's climate is profoundly ironic in light of what this book has shown about our origins... It turns out that in order to fuel our complex civilization we are lacing our planet's atmosphere with carbon dioxide, a greenhouse gas that, if it has not already begun doing so, will soon warm the Ice Age climate to which we owe our very existence." (p. 247)
"Not since Richard Rhodes' The Making of the Atomic Bomb have I been so captivated by a nonfiction book." -- Douglas Preston, The Los Angeles Times
Do all of us humans owe our existence to Panama? Stanley thinks so. Stanley's theory is that the formation of the Isthmus of Panama caused the birth of the Ice Age of about 2.5 million years ago. This Ice Age, in turn, changed the climate around the world--including the home of our ancestors. This geologically rapid transition of the African landscape forced changes in the fauna and a split in the species Australopithecus into Homo and the now extinct Paranthropus (frequently called Australopithecus boisei and robustus). The idea is that form had to follow function. An environmental crisis forced Australopithecus to either change and adapt or become extinct.

The majority of the book details Stanley's ideas and the facts he has found to support them. The final chapter (which includes all the quotes found on this page) waxes more philosophical. In it he points out some of the flaws of natural selection. He states

Natural selection produced certain traits to the benefit of our distant ancestors and then failed to remove these features even after they had lost their value. On balance our wisdom teeth, for example, probably do more harm than good in a modern jaw that, more often than not, proves too small to accommodate them. Other human traits have been flawed or problematical from the very start--products of evolutionary compromise or of some other deficiency of natural selection. A more perfect process would have done better than to saddle us with infants who cannot walk unattended for their first fifteen months of life. (p. 213)
He also delves into questions regarding the risks around our current unnatural selection including genetic manipulation.

Children of the Ice Age is not without its problems. More maps and illustrations are needed. Those the book does contain are sometimes confusing or not well explained. (Figure 7.2, for instance, still means absolutely nothing to me after countless readings.) The book, in total, is far too redundant. Several of the main points are stated in basically the same way a half dozen times or more. It is almost as if Stanley thinks that retelling the story again and again will make his theories more valid. Likewise, his overall tone and style are a little too conclusive and dogmatic for my tastes. A few pieces of new evidence can partially or completely overturn some of his views, but a reader can't easily tell this from the text. Finally, creationists will love to pull quotes out of context in this book and it is partially Stanley's fault. Even though he uses phrases like "rapid evolution" frequently, I only once (p. 229) noticed that he couched the word "rapid" with the correct phrase of "geologically speaking". Some readers may get the false impression Stanley thinks Australopithecus turned into Homo almost overnight.

Overall, however, Children of the Ice Age is a very interesting and thought-provoking work. Further evidence may bolster Stanley's case. Those interested in human evolution will certainly want to read this book for its frequently original (and possibly correct) ideas.

We cannot know ourselves deep to the core without understanding our origins. When we dig into our evolutionary genealogy, our motives resemble those of an adopted child who, in the course of an otherwise happy life, seeks to identify biological ancestors. (p. 213)
from the publisher:
A prophet of the punctuational model of evolution--which holds that evolution occurs in bursts of activity, as opposed to gradually and continually over time--ponders why the big-brained genus Homo appeared so quickly and its ancestor, Australopithecus, disappeared after thriving for nearly 1.5 million years. Stanley, a paleobiologist, contends that this came about because of the "catastrophic birth" spawned by the sudden and random effects of the modern ice age in Africa. The ice age caused forested areas to shrink, bringing Australopithecus down from its home in the trees and freeing its hands to care for its young. These changes in behavior permitted the growth and evolution of Australopithecus' brain. In all, Stanley weaves together the many evolutionary threads that form Homo sapiens.

Dr. Steven Stanley received his Ph.D. in geology from Princeton University. He is currently Professor of Paleobiology in the Department of Earth and Planetary Science at the Johns Hopkins University. Dr. Stanley has received several honors including the Charles Schubert Award of the Paleontological Society and election into the National Academy of Science and American Academy of Arts and Sciences. He is author, co-author or editor of numerous works on paleobiology, paleontology and evolution. Dr. Stanley's research interests include functional morphology and evolution of bivalve mollusks and other taxa with fossil records; rates and patterns of evolution and extinction; benthic marine ecology and paleoecology; and biomechanics.

As we steer civilization into the future, we gain perspective by looking over our shoulder to the path already taken--the actual path of our biological and cultural evolution--as opposed to the fanciful paths portrayed in creation myths. Our perspective broadens when we view the journey in context, assessing the environmental changes that our ancestors either endured or engineered along the way. (p. 214)