What Evolution is

If you are a Biologist or are a curious naturalist this is a book for you. Mayr makes an outstanding abstract of evolution, he clearly defines it with mastery. I would just like to add that this is my favorite subject and have read a good amount of books on evolution and this is clearly one of the best (don't be mislead by the size nor the price). Of course there are huge treatises on evolution (like The Structure of Evolution, of Stephen Jay Gould), but such a Bible is, for most of the cases, unpractical and unnecessary. Mayr clears evolutions' place in Biology putting it at its' very center. Great book, great style.

The term "Evolution" refers to organisms changing as they reproduce and generate. Over millions of generations, the accumulated changes are substantial and diverse enough that descendants and progenitors can no longer be included in the same species. This is fact, not theory. But by what path did the ecosystems of yesterday change into the current biosphere? What "forces" operate on specie to push them one way or another? What is selected, and what process does the selection? Tentative answers to these questions are what we call theory. A theory is an explanation of accepted facts. Evolution is not "just a theory". The word refers to both a fact and to a theory to explain the fact. Let's compare with physics 400 years ago. For instance, let's look at the theory of things-falling-down. Everybody agrees that things fall down when deprived of support. "Things-falling-down" is thus fact. Aristotle stated that heavy objects fall faster. That was a >>theory<< of things-falling-down; it tried to describe precisely how things fall down. It so happens that Aristotle's theory was wrong, as Galileo found when he began measuring how fast balls rolled down a inclined plane. <p>That a theory of gravity was found incorrect did not nullify the fact of gravity. Same with evolution.<p>Evolution is documented. Examples of speciation (one species coming from another) abound in the fossil record. These are the facts. Men like Mayer, Gould, Dawkins study the "how" of these facts. They are the great theorists seeking to explain how evolution works. That it does is obvious, how it does less so.

This is a very good introductory overview of evolutionary theory, suitable for the enthusiastic novice, the educated skeptic, the qualified biologist, or for those who simply wish to know what has been going on in this fascinating field for the last 150 years and more of scientific enquiry. The writer, Ernst Mayr, only recently passed away aged over 100, and had been through a good deal of this scientific development, and is therefore in a unique position to approach the subject. Jared Diamond (author of 'The Third Chimpanzee', 'Guns, Germs and Steel') describes the result: "there is no better book on evolution". Whilst a little skeptical of this hyperbole, I decided to check it out, and wasn't disappointed. Discussions range from the philosphical (everything in this Earth seems to be in a state of flux" p7), to the palaeontological ("the older the strata in which a fossil is found...the more different the fossil will be from living relatives" p13-although see also the occassional stasis of the genotype on p278-79), to the embryonic (eg 'recapitulation'-an important point), to the modern discovery of 'transposable elements' (gene jumping and copying-p100). Important developments in the theory include the 'branching theory' of Darwin (p19), to the theory of common descent (p21), to discussions of biogeography (species distribution), molecular biology (including the molecular clock), to the formation of new genes by doubling and insertion, leading to diversification (p108-9). The reader will find all the scientific development and current investigations exhaustive, but (hopefully!) rarely exhausting. The causes of speciation have come along way since Darwins 1859 Origin: allopatric,dichopatric, peripactic, sympatric (not found in mammals p180), instantaneous (chromosome doubling), parapatric, and hybridisation. Concepts to ponder over-in case of being caught out at parties. The historical background of 19th century philosophy is introduced (for which modern day philosophy is a little embarrassed) including 'essentialism' (constant essence of species ie "a natural kind"-with variants either irrelevant or accidental), and 'finalism' (the belief that everything moves toward greater perfection -eg Kant, and others), as compared to Malthus', Wallace's and Darwin's 'population thinking' (the study of variation in populations-a crucial concept). 3 theories of evolution are based on essentialism -transmutationism (origin of new types by mutation or saltation), transformationism-gradual change to a new natural 'type' by the influence of the environment, including use and disuse or inheritance of acquired characters (ie Lamarckism), and orthogenesis-the propensity of the living world to move towards perfection (typified by Kant, amongst others). (There are querks possible in these examples-for example some transmutational theories may be non-essentialist- however these 'higher arguments' are sometimes over semantics as much as over concepts). 'Essent

What Evolution Is written by Ernst Mayr is a well written lucid account of the current accepted explanation of evolution. This compelling book by the grand old man of evolutionary biology really brings home, to the general reader, a spirited defense of the Darwinian explanation of evolutionary biology.Mayr really gets to the heart of the question... why evolution, what evidence, and the role of organic diversity. Mayr has spent seventy years in search of the answers and reading this book reveals answers to some of the most challenging problems posed by evolutionary theory, or as Mayr likes to put it, evolutionary fact.Yes, those who need more evidence to prove evolution; why are you hedging. The clains of the creationists have been refuted so frequently and so thoroughly that there is no need to cover this subject once more. Publications by Alters, Eldredge, Futuyma, Kitcher, Montagu, Newell, Peacocke, Ruse, and Young all are in concert with Mayr... evolution is fact.Mayr believes that the story of evolution as it is worked out during the past fifty years continues to be attacked and criticized. The critics either hold an entirely different ideology, as do the creationists, or they simply misunderstand the Darwinian paradigm. The dogma of religion should be left out of the discussions of evolution as irrelevant, as religion is not a biological process.Mayr discusses the reductionist approach, an approach that reduces everything down to the level of the gene. As Mayr describes this in a refreshingly nontechnical language, you can appreciate evolutionary phenomena much better.An interesting section toward the back of the book in the fianl section where Mayr has a rather provocative approach of evolution as it is related to viewpoints and values of modern man. I found this to be very enlightening and fascinatingly compelling bringing insight and clarity to human evolution, and how did mankind evolve.If you like to read about evolution, evolutionary biology, and want a clear straight forward appoach, this is the book for you as Mayr pulls no punches as the question is asked... Are humans alone? Are we the only intelligent beings in this vast universe? Mayr says, "Alas, the rutted road from bacteria to humans is long and difficult. Following the origin of life on Earth there were nothing but prokaryotes for the next billion years, and highly intelligent life originated only about 300,000 years ago, in a single one of the more than one billion species that had arisen on Earth. These are indeed long odds.""Yes, for all practical purposes, man is alone." We can only consider this that evolution is something unexpected, but it happened anyway dispelling the odds.

(But not for dummies.)Perhaps the most remarkable thing about this book is that the author was born in 1905. What legendary biologist Ernst Mayr might next want to share with us is his secret for remaining so mentally acute for so many years! Reading this exposition on evolution by "The world's greatest living biologist and a writer of extraordinary insight and clarity" (Stephen Jay Gould, on the jacket cover) is somewhat like taking Evolution 101 as it might be taught by Professor Mayr. As he writes in the Preface, his purpose is didactic. He would like us to know more about evolution and how it works.First he presents the evidence for evolution, explaining (I hope) once and for all how evolution can be established as a fact even though we cannot perform experiments as we might in physics or chemistry: "Evolution...must be inferred from observations. Such inferences subsequently must be tested again and again against new observations, and the original inference is either falsified or considerably strengthened..." (p. 13) He adds on page 276, "I cannot see why...an overwhelming number of well-substantiated inferences is not scientifically as convincing as direct observations. Many theories in other historical sciences, such as geology and cosmology, are also based on inferences. The endeavor of certain philosophers to construct a fundamental difference between the two kinds of evidence strikes me as misleading."To this I might add that all the evidence we have of the external world is from inference. Even so-called direct observations (whatever they may be) are inferences from the evidence of our senses and must be checked against the same inferences that others make.Next Mayr explains how change and adaptation take place. He then explains why there is biodiversity. These are the first three parts of the book. Part Four is on human evolution and Chapter 11 in particular is a splendid, concise interpretation of the evidence for human evolution.One of the thorny issues Mayr addresses is selection. He explains that it is the individual (the phenotype) that is selected, and not the gene and not the population. "[A] gene as such can never be the object of selection" because it "is only part of a genotype, whereas the phenotype of the individual as a whole (based on the genotype) is the actual object of selection." (p. 126) The gene cannot be the object of selection for another reason, namely that a single gene seldom, if ever, acts independently of other genes. They work together to bring about some feature of the phenotype and are subject to the action of regulatory genes (hox and pax genes). (p. 127) Furthermore, "Many genes do not have standard selective value. A gene may be beneficial when placed in one particular genotype, but it may be deleterious when placed in a genotype with different genes." (p. 128)One of the things I learned here (p. 129) is that the phenotype includes "all the products of the behavioral genes. This inclu