Excerpts

Foreword In 1860, a debate took place in the Oxford University Museum of Natural History. The hall where this debate took place still exists, although it's now divided by a mezzanine floor into an upper "Huxley Room," and a lower "Wilberforce Room." The names of the rooms enshrine the main protagonists of that debate. The debate followed a lecture by an American academic on the subject of evolution, and soon burgeoned into a full-blown confrontation between science and religion. The Bishop of Oxford, Samuel Wilberforce, laid into the new theory of evolution through natural selection, expressing his doubts that species could change over time. Among the scientists in the room was Thomas Henry Huxley, who would become known as "Darwin's Bulldog." Wilberforce went on to challenge Huxley: on which side of his family did he claim descent from a monkey -- on his grandmother's side or his grandfather's? There are different accounts of precisely how Huxley responded to Wilberforce's sarcastic enquiry. Here's Huxley's own recollection of his reply: "If then, said I, the question is put to me would I rather have a miserable ape for a grandfather or a man highly endowed by nature and possessed of great means of influence and yet who employs these faculties and that influence for the mere purpose of introducing ridicule into a grave scientific discussion, I unhesitatingly affirm my preference for the ape." One commentator remembered perhaps what Huxley wished he'd said -- muttering first "The Lord hath delivered him into my hands," before delivering this decisive blow: "I would rather be the offspring of two apes than be a man and afraid to face the truth." Whatever was actually said, Huxley's contribution to the debate has become legendary. I think that this is partly down to one of the enduring anxieties that evolution seems to provoke. We humans have always been keen to place ourselves on a pedestal, to emphasize the gulf between us and the rest of life on the planet. The concept of humans as a special creation, made by an intelligent designer, stands in direct opposition to the idea that we are a product of unthinking natural selection: that we have evolved, like every other species on the planet. The acceptance of the fact of evolution involves the acknowledgement that humans are animals. Huxley's open recognition of his humble pedigree showed that he was willing to accept this scientific truth -- even if it meant that he had to knock himself, and the rest of humanity, off a pedestal. While humans are undoubtedly unusual animals, and unusual apes, it really is impossible to adhere to the idea of special creation if you look at the evidence around you. Our bodies and our genes are uncannily like those of other mammals, especially primates. And we now have a great fossil record of the ancestors of humans. Five weeks before the famous debate in Oxford, Wilberforce had written a fairly damning review of Darwin's On the Origin of Species . He wrote about the lack of any fossil evidence to show one species gradually changing into another. To some extent, he was right. The fossil record in the mid-nineteenth century was patchy at best. Of course, there are still gaps -- it is, after all, very rare for a dead organism to become fossilized. But a huge wealth of fossil evidence has come to light since Darwin's time. For example, we now have good evidence of the transition from aquatic to terrestrial existence in early amphibians; of the ancestral whales who would eventually lose their hind legs entirely; of feathered dinosaurs who were ancestral to birds; and of hominins -- a whole family of apes who walked upright on two legs, including Homo sapiens . These hominin fossils also show that human-ness didn't just suddenly appear. Features that we consider to be definitively, even uniquely, human, arrived in a piecemeal fashion, over vast expanses of time. And actually, it's only with hindsight that we can say that these features accumulated to a point where we can say "this is a human." In fact, you can take any species you want and trace its evolutionary history in a similar way. And you find the same thing: a piecemeal accumulation of features until we end up with a species we're familiar with today. Tracing evolutionary histories like this also takes us back to common ancestors with other species, and indeed with whole groups of species, until we can reconstruct the huge, branching tree of life on the planet. Evolution, then, explains not just the appearance of individual species, including our own, but the entire diversity of life on Earth. Evolution proceeds gradually, both in terms of genetic changes, and in the outward appearance of animals. But -- admittedly only with the benefit of hindsight -- it is possible to identify key points in evolutionary history which had huge implications for the way organisms continued to evolve. Such key moments include the appearance of the first eukaryotic cells, paving the way for the evolution of complex organisms; the evolution of animals which can survive out of water; and the appearance of flowering plants, together with the insects which evolved to pollinate them. In these pages, you can focus in on the characteristics of individual plants and animals -- but you can also pull back, to look at the wider picture, to place those species in context. There's a useful timeline guide to key events popping up just when you need it. This book sets out to present the beautiful and awe-inspiring range of biodiversity, past and present. It's a fantastic guide to life on this planet, starting with the earliest hints of living creatures preserved in rocks, then looking at plants, and at major groups of animals. In this way, we learn about not only the adaptations we see in living species, but also how those adaptations arose. And we discover how each species -- including our own -- is connected with others: with past ancestors and living cousins. We're all tiny twigs on the great Tree of Life. Alice Roberts Anatomist and Physical Anthropologist, Writer, and Broadcaster Bristol, UK Excerpted from Evolution: The Whole Story by Steve Parker All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.