George Gaylord Simpson

George Gaylord

American Zoologist, Evolutionist and Paleontologist known for Modern Synthesis, Quantum Evolution and anticipating Punctuated Equilibrium

Author Quotes

Man has risen, not fallen. He can choose to develop his capacities as the highest animal and to try to rise still farther, or he can choose otherwise. The choice is his responsibility, and his alone. There is no automatism that will carry him upward without choice or effort and there is no trend solely in the right direction. Evolution has no purpose; man must supply this for himself. The means to gaining right ends involve both organic evolution and human evolution, but human choice as to what are the right ends must be based on human evolution.

The search for historical laws is, I maintain, mistaken in principle.

Nothing I learned [in high school] had any bearing at all on the big and real questions. Who am I? What am I doing here? What is the world? What is my relationship to it?

The theory here developed is that mega-evolution normally occurs among small populations that become pre-adaptive and evolve continuously (without saltation, but at exceptionally rapid rates) to radically different ecological positions. The typical pattern involved is probably this: A large population is fragmented into numerous small isolated lines of descent. Within these, in-adaptive differentiation and random fixation of mutations occur. Among many such in-adaptive lines one or a few are pre-adaptive, i.e., some of their characters tend to fit them for available ecological stations quite different from those occupied by their immediate ancestors. Such groups are subjected to strong selection pressure and evolve rapidly in the further direction of adaptation to the new status. The very few lines that successfully achieve this perfected adaptation then become abundant and expand widely, at the same time becoming differentiated and specialized on lower levels within the broad new ecological zone.

Now we do have many examples of transitional sequences.

This regular absence of transitional forms is not confined to mammals, but is an almost universal phenomenon, as has long been noted by paleontologists. It is true of almost all orders of all classes of animals, both vertebrate and invertebrate. A fortiori, it is also true of the classes, and of the major animal phyla, and it is apparently also true of analogous categories of plants.

Certainly paleontologists have found samples of an extremely small fraction, only, of the earth's extinct species, and even for groups that are most readily preserved and found as fossils they can never expect to find more than a fraction.

Of course the orders all converge backward in time, to different degrees.

To put it crudely but graphically, the monkey who did not have a realistic perception of the tree branch he jumped for was soon a dead monkey—and therefore did not become one of our ancestors.

Darwin recognized the fact that paleontology then seemed to provide evidence against rather for evolution in general or the gradual origin of taxonomic categories in particular.

Organisms, of course, have various characteristics in common, in degrees varying from such minimal resemblance as between, say, a man and a sequoia to the maximal resemblance of identical twins. Nevertheless, no two organisms, not even identical twins, are exactly alike. Each is the product of a history both individual and racial, and each history is different from any other, both unique and inherently unrepeatable. These aspects of biology deal not with the immanent, the inherent and changeless characteristics of the universe, but with contingency, its states, fleeting and in ceaseless change, each derived from everything that went before and conditioning everything that will follow. The possibilities of prediction are loose and limited, in principle because contingent states are unique and never exactly repeated, and even more so in practice because the historical antecedents are enormously complex and practically unknowable in complete detail. These facts also rule out the parity of prediction and explanation. Part of the explanation of what an organism is obliviously depends on what its ancestors were, what chances have occurred, and why and how. This is explanation after the fact, a posteriori, or by what has been called postdiciton. It is quite different from prediction, and the possibilities of prediction in an evolutionary sequence are decidedly limited. Thus principles firmly advanced as applicable to the philosophy of science in general are not in fact applicable to some of the most important aspects o biology. In this crisis surely it is obvious that the solution is not to restrict the scope of biology, practically excluding its most characteristic and most important aspects, but to broaden the scope of scientific principle and philosophy.

Every paleontologist knows that most new species, genera, and families, and that nearly all categories above the level of family appear in the record suddenly and are not led up to by known, gradual, completely continuous transitional sequences.

Recognition of this kinship with the rest of the universe is necessary for understanding him, but his essential nature is defined by qualities found nowhere else, not by those he has in common with apes, fishes, trees, fire, or anything other than himself.

He is a state of matter, a form of life, a sort of animal, and a species of the Order Primates, akin nearly or remotely to all of life and indeed to all that is material.

Scientists and particularly the professional students of evolution are often accused of a bias toward mechanism or materialism, even though believers in vitalism and in finalism are not lacking among them. Such bias as may exist is inherent in the method of science. The most successful scientific investigation has generally involved treating phenomena as if they were purely materialistic, rejecting any metaphysical hypothesis as long as a physical hypothesis seems possible. The method works. The restriction is necessary because science is confined to physical means of investigation and so it would stultify its own efforts to postulate that its subject is not physical and so not susceptible to its methods.

Human judgment is notoriously fallible and perhaps seldom more so than in facile decisions that a character has no adaptive significance because we do not know the use of it.

Splitting and gradual divergence of genera is exemplified very well and in a large variety of organisms.

I do not think evolution is supremely important because it is my specialty. On the contrary, it is my specialty because I think it is supremely important.

The attempted synthesis of paleontology and genetics, an essential part of the present study, may be particularly surprising and possibly hazardous. Not long ago, paleontologists felt that a geneticist was a person who shut himself in a room, pulled down the shades, watched small flies disporting themselves in milk bottles, and thought that he was studying nature. A pursuit so removed from the realities of life, they said, had no significance for the true biologist. On the other hand, the geneticists said that paleontology had no further contributions to make to biology, that its only point had been the completed demonstration of the truth of evolution, and that it was a subject too purely descriptive to merit the name 'science'. The paleontologist, they believed, is like a man who undertakes to study the principles of the internal combustion engine by standing on a street corner and watching the motor cars whiz by.

I don't know where to put whales. I'm sticking them here, but I don't have any reason for it.

The book before you is one of the most important ever written. No other modern work has done so much to change man’s concept of himself and of the universe in which he lives. Before Darwin the physical sciences were already well established. They had abandoned the magical and the supernatural in seeking to understand the operations of the physical universe. They had developed the basic principles of all truly scientific investigation: that natural causes should be sought for natural phenomena, and that scientific theories must be testable and tested, in terms of objective, repeatable observations. However, the most important of all phenomena, those of life, were not yet generally approached in that fully scientific wary. The usual attempts to explain the nature of life, the diversity of living things, their marvelous adaptations, and other fundamental aspects of the living world were still metaphysical, at best, and often frankly supernatural.

I have a debt, a loyalty to the museum; the best place for me to do what I wanted to do.

The fact - not theory - that evolution has occurred and the Darwinian theory as to how it occurred have become so confused in popular opinion that the distinction must be stressed.

In spite of these examples, it remains true, as every paleontologist knows, that most new species, genera, and families and that nearly all new categories above the level of families appear in the record suddenly and are not led up to by known, gradual, completely continuous transitional sequences.

The meaning of human life and the destiny of man cannot be separable from the meaning and destiny of life in general. 'What is man?' is a special case of 'What is life?' Probably the human species is not intelligent enough to answer either question fully, but even such glimmerings as are within our powers must be precious to us. The extent to which we can hope to understand ourselves and to plan our future depends in some measure on our ability to read the riddles of the past. The present, for all its awesome importance to us who chance to dwell in it, is only a random point in the long flow of time. Terrestrial life is one and continuous in space and time. Any true comprehension of it requires the attempt to view it whole and not in the artificial limits of any one place or epoch. The processes of life can be adequately displayed only in the course of life throughout the long ages of its existence.

Author Picture
First Name
George Gaylord
Last Name
Birth Date
Death Date

American Zoologist, Evolutionist and Paleontologist known for Modern Synthesis, Quantum Evolution and anticipating Punctuated Equilibrium