Biology Quotes

All social animals, including people, live under constant pressure from two competing interests: protecting themselves from others and aligning themselves with others. When these two interests are balanced, the result is dynamic social homeostasis.

~ Mystery

Far from being the smartest possible biological species, we are probably better thought of as the stupidest possible biological species capable of starting a technological civilization - a niche we filled because we got there first, not because we are in any sense optimally adapted to it.

~ Nick Bostrom

The platypus, as it turns out, derives its DNA from a menagerie of creatures. When its genome was fully decoded, it was found only to be 80% mammalian, and had genes found previously only in reptilian, bird, amphibian, and fish DNA.

~ B.c. Chase

Now the leatherback turtle overcame the heat issue via a simple, but evolutionarily impossible solution; it is the only reptile that possesses fatty insulation known as brown adipose tissue, and the only reptile that regulates a high body temperature. This brown adipose tissue is the expression of the UCP1 gene, and, aside from the leatherbacks, is found only in mammals, amphibians, and fishes. Not one other reptile has UCP1.

~ B.c. Chase

Today, the theory of evolution is an accepted fact for everyone but a fundamentalist minority, whose objections are based not on reasoning but on doctrinaire adherence to religious principles.

~ James D. Watson

Black magic, the magic of the primeval chaos, blots out or transmogrifies the true form of things. At the stroke of twelve the princess must flee the banquet or risk discovery in the rags of a kitchen wench; coach reverts to pumpkin. Instability lies at the heart of the world. With uncanny foresight folklore has long toyed symbolically with what the nineteenth century was to proclaim a reality - namely, that form is an illusion of the time dimension, that the magic flight of the pursued hero or heroine through frogskin and wolf coat has been, and will continue to be, the flight of all men.

~ Loren Eiseley

The practice of that which is ethically best—what we call goodness or virtue—involves a course of conduct which, in all respects, is opposed to that which leads to success in the cosmic struggle for existence. In place of ruthless self-assertion it demands self-restraint; in place of thrusting aside, or treading down, all competitors, it requires that the individual shall not merely respect, but shall help his fellows... It repudiates the gladiatorial theory of existence... Laws and moral precepts are directed to the end of curbing the cosmic process.

~ Thomas Henry Huxley

Few scientists acquainted with the chemistry of biological systems at the molecular level can avoid being inspired. Evolution has produced chemical compounds exquisitely organized to accomplish the most complicated and delicate of tasks. Many organic chemists viewing crystal structures of enzyme systems or nucleic acids and knowing the marvels of specificity of the immune systems must dream of designing and synthesizing simpler organic compounds that imitate working features of these naturally occurring compounds.

~ Donald J. Cram

The question of the position of man, as an animal, has given rise to much disputation, with the result of proving that there is no anatomical or developmental character by which he is more widely distinguished from the group of animals most nearly allied to him, than they are from one another.

~ Thomas Henry Huxley

There can be no doubt that the existing Fauna and Flora is but the last term of a long series of equally numerous contemporary species, which have succeeded one another, by the slow and gradual substitution of species for species, in the vast interval of time which has elapsed between the deposition of the earliest fossiliferous strata and the present day.

~ Thomas Henry Huxley

All organisms vary. It is in the highest degree improbable that any given variety should have exactly the same relations to surrounding conditions as the parent stock. In that case it is either better fitted (when the variation may be called useful), or worse fitted, to cope with them. If better, it will tend to supplant the parent stock; if worse, it will tend to be extinguished by the parent stock.If (as is hardly conceivable) the new variety is so perfectly adapted to the conditions that no improvement upon it is possible,—it will persist, because, though it does not cease to vary, the varieties will be inferior to itself.If, as is more probable, the new variety is by no means perfectly adapted to its conditions, but only fairly well adapted to them, it will persist, so long as none of the varieties which it throws off are better adapted than itself.On the other hand, as soon as it varies in a useful way, i.e. when the variation is such as to adapt it more perfectly to its conditions, the fresh variety will tend to supplant the former.

~ Thomas Henry Huxley

A totally blind process can by definition lead to anything, it can even lead to vision itself.

~ Jacques Monod

Every day, hundreds of observations and experiments pour into the hopper of the scientific literature. Many of them don't have much to do with evolution - they're observations about the details of physiology, biochemistry, development, and so on - but many of them do. And every fact that has something to do with evolution confirms its truth. Every fossil that we find, every DNA molecule that we sequence, every organ system that we dissect, supports the idea that species evolved from common ancestors. Despite innumerable possible observations that could prove evolution untrue, we don't have a single one. We don't find mammals in Precambrian rocks, humans in the same layers as dinosaurs, or any other fossils out of evolutionary order. DNA sequencing supports the evolutionary relationships of species originally deduced from the fossil record. And, as natural selection predicts, we find no species with adaptations that only benefit a different species. We do find dead genes and vestigial organs, incomprehensible under the idea of special creation. Despite a million chances to be wrong, evolution always comes up right. That is as close as we can get to a scientific truth.

~ Jerry A. Coyne

Natural selection is a mechanism for generating an exceedingly high degree of improbability.

~ Ronald A. Fisher

The tendency to variation in living beings, which all admitted as a matter of fact; the selective influence of conditions, which no one could deny to be a matter of fact, when his attention was drawn to the evidence; and the occurrence of great geological changes which also was matter of fact; could be used as the only necessary postulates of a theory of the evolution of plants and animals which, even if not at once, competent to explain all the known facts of biological science, could not be shown to be inconsistent with any.

~ Thomas Henry Huxley

The fundamental biological variant is DNA. That is why Mendel's definition of the gene as the unvarying bearer of hereditary traits, its chemical identification by Avery (confirmed by Hershey), and the elucidation by Watson and Crick of the structural basis of its replicative invariance, are without any doubt the most important discoveries ever made in biology. To this must be added the theory of natural selection, whose certainty and full significance were established only by those later theories.

~ Jacques Monod

The occurrence of successive forms of life upon our globe is an historical fact, which cannot be disputed; and the relation of these successive forms, as stages of evolution of the same type, is established in various cases.

~ Thomas Henry Huxley

When one ponders on the tremendous journey of evolution over the past three billion years or so, the prodigious wealth of structures it has engendered, and the extraordinarily effective teleonomic performances of living beings from bacteria to man, one may well find oneself beginning to doubt again whether all this could conceivably be the product of an enormous lottery presided over by natural selection, blindly picking the rare winners from among numbers drawn at random. [Nevertheless,] a detailed review of the accumulated modern evidence [shows] that this conception alone is compatible with the facts.

~ Jacques Monod

Even today a good many distinguished minds seem unable to accept or even to understand that from a source of noise natural selection alone and unaided could have drawn all the music of the biosphere. In effect natural selection operates upon the products of chance and can feed nowhere else; but it operates in a domain of very demanding conditions, and from this domain chance is barred. It is not to chance but to these conditions that evolution owes its generally progressive course, its successive conquests, and the impression it gives of a smooth and steady unfolding.

~ Jacques Monod

An irrefutable proof that such single-celled primaeval animals really existed as the direct ancestors of Man, is furnished according to the fundamental law of biogeny by the fact that the human egg is nothing more than a simple cell.

~ Ernst Haeckel

The ancestors of the higher animals must be regarded as one-celled beings, similar to the Amoebae which at the present day occur in our rivers, pools, and lakes. The incontrovertible fact that each human individual develops from an egg, which, in common with those of all animals, is a simple cell, most clearly proves that the most remote ancestors of man were primordial animals of this sort, of a form equivalent to a simple cell. When, therefore, the theory of the animal descent of man is condemned as a 'horrible, shocking, and immoral' doctrine, tho unalterable fact, which can be proved at any moment under the microscope, that the human egg is a simple cell, which is in no way different to those of other mammals, must equally be pronounced 'horrible, shocking, and immoral.

~ Ernst Haeckel

...if an organised body is not in the situation and circumstances best adapted to its sustenance and propagation, then, in conceiving an indefinite variety among the individuals of that species, we must be assured, that, on the one hand, those which depart most from the best adapted constitution, will be the most liable to perish, while, on the other hand, those organised bodies, which most approach to the best constitution for the present circumstances, will be best adapted to continue, in preserving themselves and multiplying the individuals of their race.

~ James Hutton

(Evolution) general condition to which all theories, all hypotheses, all systems must bow and which they must satisfy henceforward if they are to be thinkable and true. Evolution is a light which illuminates all facts, a curve that all lines must follow.

~ Pierre Teilhard De Chardin

A century ago, people laughed at the notion that we were descended from monkeys. Today, the individuals most offended by that claim are the monkeys.

~ Jacob M. Appel

An evolutionary perspective of our place in the history of the earth reminds us that Homo sapiens sapiens has occupied the planet for the tiniest fraction of that planet's four and a half thousand million years of existence. In many ways we are a biological accident, the product of countless propitious circumstances. As we peer back through the fossil record, through layer upon layer of long-extinct species, many of which thrived far longer than the human species is ever likely to do, we are reminded of our mortality as a species. There is no law that declares the human animal to be different, as seen in this broad biological perspective, from any other animal. There is no law that declares the human species to be immortal.

~ Richard E. Leakey

This new consensus seemed so compelling that Ernst Mayr, the dean of modern Darwinians, opened the ashcan of history for a deposit of Geoffrey's ideas about anatomical unity.

~ Stephen Jay Gould

The evolution of life, and the evolutionary origin of mankind, are scientifically established as firmly and completely as any historical event not witnessed by human observers. Any concession to anti-evolutionists, suggesting that there are scientific reasons to doubt the facticity of evolution, would be propagating a plain untruth.

~ Theodosius Dobzhansky

Evidently neither cats nor dogs, nor other animals that listen to human music, were constituted for the appreciation of it, for it is not of the slightest use to them in the struggle for existence. Moreover, they and their organs of hearing were much older than man and his music. Their power of appreciating music is therefore an uncontemplated side-faculty of a hearing apparatus which has become on other grounds what we find it to be. So it is, I believe, with man. He has not acquired his musical hearing as such, but has received a highly developed organ of hearing by a process of selection, because it was necessary to him in the selective process ; and this organ of hearing happens also to be adapted to listening to music.

~ August Weismann

It was in the attempt to ascertain the interrelationships between species that experiments n genetics were first made. The words evolution and origin of species are now so intimately associated with the name of Darwin that we are apt to forger that the idea of common descent had been prominent in the mnds of naturalists before he wrote, and that, for more than half a century, zealous investigators had been devoting themselves to the experimental study of that possibility. Prominent among this group of experimenters may be mentioned Koelreauter, John Hunter, Herbert Knight, Gartner, Jordan. Naudin, Godron, Lecoq, Wichura--men whose names are familiar to every reader of Animals and Plants unders Domestication.

~ William Bateson

As long as museums and universities send out expeditions to bring to light new forms of living and extinct animals and new data illustrating the interrelations of organisms and their environments, as long as anatomists desire a broad comparative basis human for anatomy, as long as even a few students feel a strong curiosity to learn about the course of evolution and relationships of animals, the old problems of taxonomy, phylogeny and evolution will gradually reassert themselves even in competition with brilliant and highly fruitful laboratory studies in cytology, genetics and physiological chemistry.

~ William King Gregory

I'm doing now with cornets exactly what I used to do with trilobites: measuring, analyzing and cataloging the myriad gradations of their forms.

~ Niles Eldredge

More about the selection theory: Jerne meant that the Socratic idea of learning was a fitting analogy for 'the logical basis of the selective theories of antibody formation': Can the truth (the capability to synthesize an antibody) be learned? If so, it must be assumed not to pre-exist; to be learned, it must be acquired. We are thus confronted with the difficulty to which Socrates calls attention in Meno [ ... ] namely, that it makes as little sense to search for what one does not know as to search for what one knows; what one knows, one cannot search for, since one knows it already, and what one does not know, one cannot search for, since one does not even know what to search for. Socrates resolves this difficulty by postulating that learning is nothing but recollection. The truth (the capability to synthesize an antibody) cannot be brought in, but was already inherent.

~ Niels Kaj Jerne

An example of such emergent phenomena is the origin of life from non-living chemical compounds in the oldest, lifeless oceans of the earth. Here, aided by the radiation energy received from the sun, countless chemical materials were synthesized and accumulated in such a way that they constituted, as it were, a primeval “soup.” In this primeval soup, by infinite variations of lifeless growth and decay of substances during some billions of years, the way of life was ultimately reached, with its metabolism characterized by selective assimilation and dissimilation as end stations of a sluiced and canalized flow of free chemical energy.

~ R.w. Van Bemmelen

This view, as a rounded whole and in all its essential elements, has very recently disappeared from science. It died a royal death with Agassiz.[It had formerly been held that there were no genetic connections among species.]

~ Asa Gray

For three million years we were hunter-gatherers, and it was through the evolutionary pressures of that way of life that a brain so adaptable and so creative eventually emerged. Today we stand with the brains of hunter-gatherers in our heads, looking out on a modern world made comfortable for some by the fruits of human inventiveness, and made miserable for others by the scandal of deprivation in the midst of plenty.

~ Richard E. Leakey

Evolution is a blind giant who rolls a snowball down a hill. The ball is made of flakes—circumstances. They contribute to the mass without knowing it. They adhere without intention, and without foreseeing what is to result. When they see the result they marvel at the monster ball and wonder how the contriving of it came to be originally thought out and planned. Whereas there was no such planning, there was only a law: the ball once started, all the circumstances that happened to lie in its path would help to build it, in spite of themselves.

~ Mark Twain

The expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient.

~ Charles Darwin

Evolution is the law of policies: Darwin said it, Socrates endorsed it, Cuvier proved it and established it for all time in his paper on 'The Survival of the Fittest.' These are illustrious names, this is a mighty doctrine: nothing can ever remove it from its firm base, nothing dissolve it, but evolution.

~ Mark Twain

The secrets of evolution are death and time—the deaths of enormous numbers of lifeforms that were imperfectly adapted to the environment, and time for a long succession of small mutations.

~ Carl Sagan

I have been scientifically studying the traits and dispositions of the “lower animals” (so-called,) and contrasting them with the traits and dispositions of man. I find the result profoundly humiliating to me. For it obliges me to renounce my allegiance to the Darwinian theory of the Ascent of Man from the Lower Animals; since it now seems plain to me that that theory ought to be vacated in favor of a new and truer one, this new and truer one to be named the Descent of Man from the Higher Animals.

~ Mark Twain