Upright Ape [Hardcover]

To understand how and why we got here, one has to look at the history of how we evolved to the bipedal, upright, and thinking species that we are today. In his book, The Upright Ape: A New Origin of the Species, biologist and neurosurgeon Dr. Aaron Filler proposes that a key element to unfolding the mysteries that have challenged evolutionary biologists for centuries lies within our bones, particularly the spine.

Dr. Filler explains that to fully understand evolution, we must study the early pioneers of evolutionary theory and the influence of their era's philosophical, religious, and cultural beliefs. Filler proposes that although Darwin's theory of evolution is a key element to understanding evolution, the concept of a slow process of descent with modification is not the final conclusion of our evolutionary story. By examining the works of a number of evolutionary pioneers such as Johann Wolfgang von Goethe and Etienne Geoffroy Saint-Hilaire, Dr. Filler is able to build on their early findings and show through his own research that locomotion and the development of the spine is a key feature to understanding how humans evolved.

Drawing on such works of Mendel's Nature of Heredity as well as Pre-Darwinian and Post-Darwinian researchers, Filler proposes that evolution had the ability to accelerate, even in an instant. Using modern technology to study fossilized species, the bone structure of species such as the ape, fish, birds, as well as the human skeletal structure, Dr. Filler presents compelling evidence that the building blocks within the vertebrate embryo that initiate the formation of muscle, tissue and bone, are a common feature among the species. As well, he explains the bones and spinal segments that all vertebrates have in common. Although the various bones are located in different sections, the link among species indicates a common history with various evolutionary branches. That is, there is a common connection among species, but evolution is not a single straight path. It is more like a tree with various branches that contain common evolution building blocks. Filler proposes that the split between human and chimpanzee on the evolutionary ladder is the result of an upright ancestral ape with the apes we see today having evolved from a different evolutionary branch than humans. He explains in detail how the human spine evolved and how the modern ape is actually a descendant of humans.

The Upright Ape: A New Origin of the Species is a compelling and well-presented analysis of the story of life. With an in-depth examination of evolutionary pioneers and their influences on today's research, Dr. Aaron Filler presents a convincing theory of evolution that will educate, stimulate, and challenge our perceptions of the history of life. I highly recommend the book not only to science students, but to readers who enjoy engaging and well-researched books that inspire debate and reflection.

Tracy Roberts, Write Field Services

Review by Kirkus Discoveries

A neurosurgeon and evolutionary scholar presents a bold new theory on the early origins of the hominiform (human-like) primates.

For some time, a critical part of humankind's self-image as a species has been our sense of superiority to the rest of the animal kingdom, including our close genetic cousins. After all, even though we share a common ancestor, humans learned to walk upright on two feet, while gorillas and chimps still largely get around on all-fours. But what if that common ancestor actually walked upright, and gorillas and chimps have since evolved into largely quadrupedal creatures? Here, the author presents compelling evidence that this may be the case. A noted neurosurgeon and spine expert, Filler has studied under some of the most famous names in the world of evolutionary science, such as Stephen Jay Gould and Ernst Mayr. After being confronted with a fossil that bore unmistakable, unique human features, features that shouldn't have been there until millions of years later, he realized that it would take more then the standard Darwinian theories of evolution to explain the anomaly. Building on the work of visionary thinkers such as Goethe, Étienne Geoffroy St. Hilaire, Gould and others, and drawing largely on his extensive knowledge of the spine, Filler builds a strong case to refute what he sees as some of the fundamentally incorrect assumptions that evolutionary scientists hold dear. He also provides an excellent general outline of some of the history and historic trends in evolutionary thought while laying out detailed evidence to support his theory. His writing often tends to be highly technical, which can leave the average reader lost. Still, his ideas come across clearly, and he puts forth a compelling argument.

Thought-provoking and bold.
[...]

The rest of posterior basicranial growth in nonhuman primates occurs through posterior drift of the foramen magnum, which has been shown by fluorochrome dye labeling experiments to migrate caudally in nonhuman primates through resorption at its posterior end and deposition at its anterior end (Michejda, 1971; Giles et al., 1981). In contrast, the foramen magnum remains in the center of the human skull base, roughly halfway between the most anterior and posterior points of the skull (Lugoba and Wood, 1990).

The Primate Cranial Base: Ontogeny, Function, and Integration
Lieberman, Ross, and Ravosa
YEARBOOK OF PHYSICAL ANTHROPOLOGY 43:117-169 (2000)

The posterior drift of the foramen magnum in nonhuman primates is controlled by Hox genes - or at least that is what we infer based on studies in mice. There are a few studies, but not many, that seek to integrate recent developments in evo-devo into paleoanthropology. There are none that seek to integrate modularity theory into paleoanthropology.

So I was quite happy to receive a copy of The Upright Ape: A New Origin of the Species by Aaron G. Filler. The Upright Ape is a well written, sometimes polemical, attempt to combine recent advances in genetics, evo-devo and paleoanthropology into a theory about bipedality. Although the aim of the book is to explain the origins of bipedality, it actually ranges over a wide variety of fields. The first couple of chapters are devoted to the vertebral theory suggested by Goethe, the adventures of Etienne Geoffroy Saint-Hilaire in Egypt (and the impact of Egyptian iconography on his thought), and Geoffroy Saint-Hilaire's idea about the inversion of the dorsal-ventral axis in vertebrates. The next three chapters discuss chromosomal speciation, taxonomy and homology, and modular selection theory. These chapters form the foundation for the final four chapters where Filler attempts to explain five major events in the history of life. These five events are the Cambrian Explosion, the origin of the vertebrates, the appearance of the dinosaurs, the mammalian diversification, and the origins of bipedality. For Filler all of these events share a common denominator. Namely a change in body plan that is ultimately related to Hox genes acting on higher order modules, such as the somites.

One example will have to suffice. Morotopithecus is a large bodied species of primate dating to the early Miocene (approximately 20.6 MYA). Morotopithecus has been called enigmatic because of its wide variety of traits, some of which link it to primitive catarrhines, others to modern hominoids. Cranially, em>Morotopithecus is characterized by a narrow interorbital region, broad nasal aperature, broad palate, pronounced canine jugum, long snout and short maxilla. Dentally it is characterized by procumbent incisors, large, sexually dimorphic canines, large quadrate molars (both primitive catarrhine traits), and broad premolars (such as in extant apes). Postcranially Morotopithecus has a rounded and superiorly expanded glenoid fossa (similar to a chimps), the articular surface on the head of the femur resembles that of monkeys (suggesting lesser ability to engage in abducted postures), a broad, shallow patellar grove, and thick diaphyseal cortical bone in the femur. The lumbar vertebrae share a number of features with modern hominoids such as a caudally inclined spinous process and a transverse process that arises from the pedicle. The lumbar vertebrae are also cranio-caudally long (unlike in modern hominoids). In most mammals, including hylobatids the lumbar transverse process is serially homologous with the rib. Most mammals, including lemurs, monkeys, hylobatids, and Proconsul africanus have a styloid process on their lumbar vertebrae. Humans, great apes and Morotopithecus don't. Filler argues that the reason for this is because the transverse process had switched and become serially homologous with the spinous process (well, with the structures giving rise to the spinous process). This indicates a fundamental body plan change - it moves, for example, the muscle attachments away from the midline increasing their leverage. It also allows for more upright posture. In the case of Morotopithecus more upright posture means fully bipedal. This has certain implications for the way apes and humans evolved (apes evolved away from bipedality - hence knuckle-walking is derived and bipedality the primitive condition) and Filler doesn't shy away from spelling these issues out.

For a book with only 260 pages Filler manages to pack an amazing amount of information into it, his discussion of the effects of rib and spine morphology among dinosaurs and mammals is a good example. At the same time the book doesn't suffer, in terms of readability, because of that. Although I can't say that I agree with everything in the book (leaving Morotopithecus aside, chromosomal speciation is on shaky ground, for example) I will echo Pilbeam, from the introduction, and say that this is a challenging and provocative book, well worth reading.

afarensis blogs at [...] where this review appeared in its original form.