Extinct Humans

This is the most beautifully illustrated of the four books on paleontology I've read recently. The full-color plates really allow you to connect the comparative anatomy discussed in the text with the visible features. Tattersall and Schwartz write well and the text never gets dry or technical. Richard Klein's The Dawn of Human Culture is excellent also and has very clear explanations of high-tech dating methods such as radioisotope dating, thermoluminesence, ESR or electron spin resonance dating, and magnetic-field dating, and he's careful to discuss their strengths and weaknesses, and the technical difficulties and limitations involved in using them.A major strength of the book is discussing the changes in paleontologists' approach to the taxonomy. An example of a major change is Homo habilis, thought to be the first true tool-using homonid. Consider what happened with one of the so-called "type fossils." Type fossils are the ones that the original definition of the species came from. The problem concerned the type fossils of Homo rudolphensis, known as ER 1470, which were quite famous. H. rudolphensis was an important hominid find with a larger cranial capacity than homo habilis, and was considered a more evolved, later species. It's mostly known from an upper jaw and palate and portion of skull. However, it was discovered that the upper jaw mates almost exactly with OH 64, an Australopithecine lower jaw from Olduvai Gorge (OH means Olduvai Homonid). If this is true, Homo rudolphensis disappears as a species and OH 64 no longer belongs in Australopithecus. As the authors point out, that was especially ironic since ER 1470, although it's still currently assigned to H. rudolphensis, was originally put in H. habilis and was the find which finally convinced scientists that there was something to define the species after all, despite the chaos that had reigned up to that time.Their difficulties didn't stop there. Because of the enormous influence of evolutionary biologist Ernst Mayr and the population geneticist Theodosius Dobzhansky, whose ideas caused paleoanthropologists to think in terms of a single, evolving homonid line from Australopithecus to Homo erectus to Neanderthal to Homo sapiens, paleontologists were for many years reluctant to create new species for their finds, despite the obvious difficulty of fitting so many anatomically distinct fossils into a single species of Homo habilis. As a result, H. habilis became a virtual dumping group for various fossil finds, and only in the last decade were all the different finds reconsidered.The authors include superb discussions of the fossil and cultural (tool-making) evidence for Homo heidelbergensis and Homo antecessor, considered to be the last common ancestor of the homonid line which led to H. sapiens and Neanderthal. H. heidelbergensis, they point out, also has become a convenient dumping ground for a number of fossils 300,000 to 600,000 years old which have a cranial capacity of around 12

It's been 20 years since I read up much on the paleoanthropology, so I thought I'd get up to date and read some of the recent books on the subject. One thing I noticed right away, compared to when I was last studying the subject in college, was how our evolutionary tree was now much "bushier," compared to what we knew back then. Now it's thought that there were at least 3 or 4 different species of Australopithecines, and the same goes for Homo habilis, and H. erectus.Besides this book, so far I've read Paul Jordan's Neanderthal, Richard Leakey's The Origins of Humankind, and Richard Klein's The Dawn of Human Culture. They're all excellent books, but Klein's and Tattersall's were both published in the last year, so they're the most recent, and include important information on the most recent finds, such as Ardipithecus ramidus, although the Sahelanthropus tchadensis discovery by the M. Brunet expedition was so recent it unfortunately doesn't appear in either book.This book is the most beauifully illustrated of the four books I've read so far. The full-color plates of the different skulls really allow you to connect the comparative anatomy as discussed in the text with the actual features. The book has very nice, glossy paper, so the photos look great, but that also means its the most expensive book of the four. Tattersall's writing is excellent and never gets dry or technical, and the Klein book is also extremely well written. Klein's book also has very clear explanations of high-tech dating methods such as radioisotope dating, thermoluminscence, ESR or electron spin resonance dating, and so on, and he also discusses their strengths and weaknesses, and the technical problems and limitations involved in using them, which I liked.The book also has an excellent introductory chapter in which the author discusses the early history of comparative fossil anatomy, including the important work of Blumenbach, who founded the science and revised and expanded on many of Linnaeus's notions about taxonomy, especially the definition of the genus Homo, and our species, Homo sapiens.The Leakey book is now almost 10 years old, and although somewhat dated, it's still worth reading, as its focus is different from these two books. It's not primarily about the comparative anatomy of the different fossil finds so much as what the changes in anatomy from the pre-homonids to the homonids meant for our physiology and ultimately our life-style. Leakey uses the fossil record to show that such human characteristics as a prolonged, helpless infancy, a more active and athletic way of life, delayed sexual maturity, the development of finer tool-making, and the advent of complex social relationships and sophisticated language, all arose during the transition from the Australopithecines to the more advanced Homo habilis and Homo erectus.Neanderthal, by Paul Jordan, is the most technical and in some ways the most difficult to read, but it's the most detailed and in-depth discussion

According to Reuters of December 5, 2000, French and Kenyan scientists unearthed fossilized remains of mankind's earliest known ancestor that is at least 6 million years old, and the find is not only much older than any else previously known but is also in a more advanced stage of evolution. More news from Reuters on March 21, 2001, and we find out that Meave and Louise Leakey are ready to shake the world with their discovery of not only a new species of early human but a new genus as well.These new findings, as well as many others, support the emerging theory that rather than being linear, the human family tree had many branches, and that present-day humans shared ancestors with other human beings who eventually became extinct.Long-existed dogmas of paleoanthropology supporting the linear model of evolution are about to fall down, and considering this, the importance of the book by Tattersall and Schwartz can hardly be overestimated.First of all, of course, the authors provide a surprisingly thorough insight into the existing knowledge of known fossils, and the job done by them is very impressive: Tattersall and Schwartz have obviously studied not only the literature and photos, they have got into a much deeper investigation, discussing a very little detail of an original fossil, and at the same time, with a help of perfect pictures and drawings, giving readers a nice chance to look at the reason of the reconsideration of the existing fossil evidence. The details of morphology brought by the authors into the light are striking and strongly supportive to their point of view. What, however, may seem to be a little disappointment is that Tattersall and Schwartz do not lead us to no less interesting field of studies, namely, the stratigraphic evidence, so we unluckily have less chance to find out more about the geological aspects of all those numerous finds, and, of course, the analysis of the sites' stratigraphy (as a part of the complicated fossils dating process) is somehow left aside.What's, however, much more important is the book objectively means a clear turn-point in the history of the official anthropology, and paleoanthropology as well. What previously could only be found in the books by Cremo and Thomson, particularly, the possibility of coexistence of different human species at a time in some extended periods of the past, now is clearly stated by officially recognized scientists. No more simplistic approaches to viewing the human evolution, no more frozen-in-time doctrines and narrow-minded announcements. We are moving forward, no matter how deep we were buried under the anthropological dogmas of the last century, and, who knows, maybe soon we will find out that human evolution looks perhaps not even as a bushy tree, but rather as a wood of trees, and it is hardly believable that at the moment we are left with only one branch of a tree.

"Extinct Humans" is a fascinating account of human evolution, extraordinarily illustrated with crisp, powerful photographs of fossils which drive home the point that these are the remains of actual beings who have inhabited this world before us, whether they were our direct ancestors or instead "cousins" to our own line of descent.Tattersall and Schwartz have studied not just the literature on the subject, but virtually all the fossils themselves, giving them a perhaps unmatched command of the variations in the homanid fossil record. They argue persuasively in a clear, well-organized text that modern Homo sapiens is the sole survivor of the many distinct homanid species which have existed over the past two million years, that most of the fossils which have been found represent not ancestors of our own specific line, but relatives which split off in different directions before ultimately coming to a literal dead end. Their discussion of the interaction between Neaderthals and modern humans in Europe (and possibly between Homo erectus and modern humans in southeast Asia) is especially absorbing, delving into questions of technological change, the emergence of symbolic thought, and the creation of language.The study of human evolution has, well, evolved enormously in the 35 years I have been interested in the topic. "Extinct Humans" is, to my way of thinking, today's best summary and analysis of current knowledge.

We were all taught in school that human evolution was linear -- Australopithicus evolved into Homo erectus who evolved into a form of Homo sapiens, or us. But all other animals have numerous speciations and dead ends. Why are humans different? The authors answer: We aren't. They discuss, in detail, the history of thought in human evolution. They go through the fossils, showing many of them in glossy color photos. They conclude that we having only one hominid species around is not the way it has always been -- we are just the ones who won out, and probably eliminated our rivals through competition or other means.Overall, a great book for anybody interested in human evolution.