From Library Journal
The role of chance in human evolution is often underemphasized by those who think in terms of purposeful change. As this book usefully demonstrates, chaos theory can give us clues about our own evolution. McKee (anthropology, Ohio State Univ.) uses computer simulations to show how apparently minute changes in the initial makeup of a simulated population cause enormous changes in the population after many generations. Environmental change does not cause evolution, he says; natural selection acts either to preserve or kill off mutations but is dependent on mutations occurring by chance to make any changes. McKee, who has excavated fossils in South Africa, is also a proponent of the role of autocatalytic evolution, in which an initial evolutionary change is affected by feedback loops. This means that the survival and spread of a mutation is affected by its impact on the functioning of the organism within its species and in the current environment and that it in turn can affect the survival of mutations in other parts of the organism. Most of McKee's ideas are not entirely new, but his working out of their implications leads to important and sometimes unorthodox insights. His clear, informal, and anecdotal writing style makes sometimes complex ideas interesting and understandable. For academic and large public libraries.DMarit MacArthur Taylor, Auraria Lib., Denver
Copyright 2000 Reed Business Information, Inc.
From Scientific American
McKee wonders, as everyone must, how we got here. "How could an aimless evolutionary process, patching together random biological novelties and oddities through trial and error, lead to Homo sapiens?" Probably humans would not appear, he says, if evolution could have restarted. "This is because the evolution of life is subject to fates wantonly dictated by three ubiquitous and mischievous forces: chance, coincidence, and chaos." Elaborating on the effects of those forces, McKee proposes a bottom-up model of evolution rather than the top-down model favored by many evolutionists. "In the standard top-down model, outside environmental influences are more important, and the species is a pivotal unit. In the bottom-up model, genetic variants must be tested through successive levels within members of a species before any adaptation to outside influences can take place." And he suggests that because of the huge number of genetic variations made possible by the large human population, "our species may be set to evolve at an unprecedented rate." McKee, associate professor in the departments of anthropology and evolution, ecology, and organismal biology at Ohio State University, has a way with examples and analogies that greatly enhances his argument. EDITORS OF SCIENTIFIC AMERICAN
From Kirkus Reviews
Add culture to the alliterative subtitle and clever to describe the approach of the author, for this is indeed an intelligent and provocative account of human evolution. McKee (Anthropology/Ohio State) is a theorist as well as a field paleoanthropologist. He has worked on digs at the storied sites in South Africa (Magapansgat and Taung) where Raymond Dart discovered a famous fossil of a child hominid, not an ape, estimated to be about 2.5 million years old. The structure of the skull provided McKee with a starting-point for his thesis: there is chaos in the world, he claims, because a change in some initial circumstance in our evolutionary history--one that occurred by chance (gene mutation)--has had epoch-making and unpredictable repercussions. The Taung child was a small-brained, large-faced biped. In the process of adapting to standing and walking, McKee speculates, the spinal cord attached to the brain moved centrally so that the head would eventually sit squarely over the spinal column and face forward. These genetic and morphological events, along with evidence from other fossil finds and computer simulations, led McKee to conclude that evolution is self-catalytic (i.e., self-driven). It is the product of change, coincidence, and chaos, climaxing in human evolution with culture, that has increased our adaptability. McKee discredits the popular theory that a climatic cooling led to a loss of forest and the growth of savannahs, thereby driving our ancestors to bipedalism. He also includes a wonderful chapter cataloguing the compromises in anatomy and physiology our species lives with, and he speculates that we are preserving maladaptive traits because of our medical ingenuity. McKee's wonderfully rich and thought-provoking text, told with style and winning flashes of humor, is a refreshing entry into the always contentious and endlessly fascinating story of human origins. -- Copyright © 2000 Kirkus Associates, LP. All rights reserved.
From the Publisher
Interview with Jeffrey K. McKee Author of The Riddled Chain: Chance, Coincidence, and Chaos in Human Evolution Q:Why did you decide to write this book?
A:People are curious about human evolution and the scientific study of our origins. A book is an effective and enjoyable means of communicating to fellow scientists and the lay public alike. This book was an opportunity to combine my responsibilities as a researcher and an educator into one work.
Q:When did you begin to formulate your theories about human evolution? What sparked your interest?
A:I began thinking about evolution when I was 13 years old. After watching Louis Leakey on the television, walking down the side of Olduvai Gorge past layer after layer of our past, I was hooked. My current theories have grown from a lifetime interest, which took new directions once I started reading about chaos theory. I am still formulating new theories, and will continue to do so. Science is a dynamic process. Thus my book is merely a step toward better ideas, not an end product of a particular research trajectory.
Q:You write, "The evolution of life is subject to fates wantonly dictated by three ubiquitous and mischievous forces: chance, coincidence, and chaos." Why do you focus this book on "wanton" fates, when other principles of evolution have been so thoroughly established?
A:Chance plays an important role at every level of biological evolution, from genetic recombination to lifetime encounters, and even to the origins of species. Genetic mutation, the mother of invention, occurs where regular biological processes meet chance. Should a mutation successfully spread throughout a population, it is a coincidence that chance met satisfactorily with survival and propagation. Chance and coincidence, along with a host of interacting biological forces including natural selection, set an unpredictable trajectory for the future of a species. The unpredictability wrought by such dynamics is the signature of chaos. Biological evolution may have vague trends, but there was nothing inevitable about human evolution. In the world of chaos, an infinite array of creatures could have evolved from our earliest ancestors - or our ancestors could have gone quietly extinct. There are many biological principles upon which life was built. We must recognize that chance, coincidence, and chaos are among the key principles that created and shaped life as we know it.
Q:You propose theories of natural selection get more credit than they deserve: why?
A:There is no doubt among biologists and paleontologists that the Darwinian notion of evolution through natural selection is very important. I have no qualms about that. But we cannot invoke natural selection as an explanation for every nuance of human biology, or for the biology of any organism. Things are not so ordered, for natural selection has limited powers. That is why I devote a chapter to what is wrong with the human body. The exigencies of chance, coincidence, and chaos have played huge roles in shaping us into the odd beings we are. My aim is to expose those roles, and balance our perspective of human evolution. Once we meld traditional selection theory with chaos theory, we are closer to understanding the nature of life and its origins.
Q:Throughout the book, you write about research you did in South Africa. Why did you choose this location for your research? What type of research did you do? How did your work there influence this book?
A:My academic placement in South Africa was largely a product of chance, like so many things in evolution. I happened to be in the right place at the right time, and was offered a position there by the renowned paleoanthropologist, Phillip Tobias. A very important part of the story of human origins played itself out in southern Africa, leaving fossil clues in numerous cave deposits. I've been privileged to help elucidate that segment of human evolution through both excavation and fossil studies. Oddly enough, my misfortune in not finding any hominid fossils during my excavations probably turned to my advantage - it made me focus more on the context and process of human evolution.
Q:What are your thoughts on creationist theories of evolution?
A:Any scientist must be open to any and all ideas and test them against the evidence. You find me one creationist, young earth or old earth, who can give a cogent explanation of the sequences in the fossil record, and I'll listen. Meanwhile, science has a better explanation that fits all the data. I've made an extensive study of creationist literature, and have yet to find any testable "theories" or scientifically valid arguments against evolution. Despite thinly veiled attempts at "creation science" or "intelligent design theory," creationism is a belief system, not a science.
There is no doubt that my portrayal of the roles of chance, coincidence, and chaos will be disquieting to some of the more fundamentalist creationists who oppose science. But many creationists accept the role of evolution in human origins. In my view, religion and science are not antithetical views of life; they are complementary.
Q:In the book you discuss computer simulations you ran to imitate the evolutionary process. Please describe your experiments and results.
A:The computer simulations are an approximation of life as we know it. We cannot recreate life's evolution, but we can create expectations of how life acts under various theoretical models. Computer simulations are thus an effective tool for looking at models of the pace of mammalian evolution, or the relative importance of chaos versus natural selection in evolution at a genetic level. Where the empirical data fit the hypothetical scenarios, we must take note. Where the data do not fit the simulated scenarios, we must rethink our notions of the evolutionary process.
From the Inside Flap
Did human evolution proceed in an inevitable fashion? Can we attribute our origins solely to natural selection, or were more mischievous forces at work? These are the questions investigation by anthropologist Jeffrey K. McKee. He argues that if we were to turn back the clock to our split from ancestral apes, evolution would proceed differently. Ever since our ancestors first stood up on two feet, natural selection undoubtedly was an important factor in guiding human evolution. But McKee shakes the standard notion that natural selection steered early hominids toward particular environmental adaptations. The fossil remains of our ancestors direction. It becomes clear that the evolutionary road to Homo Sapiens was not paved solely by natural selection; There was just a dim pat cut out by prehistoric coincidences and contingencies. Had any link in the evolutionary chain of events been slightly different, then our species would not be as t is today... or our ancestors may not have survived at all.
With both humor and awe, McKee illustrates how the chain of evolution has been riddled with chance, coincidence, and chaos. He uses familiar examples, noting that many of us exist as individuals because of chance meeting of our parents. From the present back through prehistory, chance is at the heart of our creation-as is chaos. The classic example of chaos is the butterfly effect: a single butterfly, flapping its wings, causes a tiny change in the atmosphere, which in turn amplifies to affect the course of storms on another continent. McKee ties such example of unpredictability to fossil evidence and computer simulations, revealing the natural coincidences that shaped our evolution. Although chaos exacted an evolutionary price by limiting the powers of natural selection, it also made us what we are. One can only conclude that human beings were neither inevitable- nor probable.
About the Author
Jeffrey K. McKee is an associate professor in the departments of anthropology and evolution, ecology, and organismal biology at The Ohio State University. He is the coauthor of Understanding Human Evolution.
