“Every moment dies a man,/ Every moment one is born”:
I need hardly point out to you that this calculation would tend to keep the sum total of the world's population in a state of perpetual equipoise whereas it is a well-known fact that the said sum total is constantly on the increase. I would therefore take the liberty of suggesting that in the next edition of your excellent poem the erroneous calculation to which I refer should be corrected as follows:
'Every moment dies a man / And one and a sixteenth is born.” I may add that the exact figures are 1.167, but something must, of course, be conceded to the laws of metre.

Conclusions
I. A curve has been found representing the frequency distribution of standard deviations of samples drawn from a normal population.
II. A curve has been found representing the frequency distribution of values of the means of such samples, when these values are measured from the mean of the population in terms of the standard deviation of the sample…
IV. Tables are given by which it can be judged whether a series of experiments, however short, have given a result which conforms to any required standard of accuracy or whether it is necessary to continue the investigation.

A new species develops if a population which has become geographically isolated from its parental species acquires during this period of isolation characters which promote or guarantee reproductive isolation when the external barriers break down.

A species consists of a group of populations which replace each other geographically or ecologically and of which the neighboring ones integrate or hybridise wherever they are in contact or which are potentially capable of doing so (with one or more of the populations) in those cases where contact is prevented by geographical or ecological barriers.

A species is a reproductive community of populations (reproductively isolated from others) that occupies a specific niche in nature.

An immune system of enormous complexity is present in all vertebrate animals. When we place a population of lymphocytes from such an animal in appropriate tissue culture fluid, and when we add an antigen, the lymphocytes will produce specific antibody molecules, in the absence of any nerve cells. I find it astonishing that the immune system embodies a degree of complexity which suggests some more or less superficial though striking analogies with human language, and that this cognitive system has evolved and functions without assistance of the brain.

Any child born into the hugely consumptionist way of life so common in the industrial world will have an impact that is, on average, many times more destructive than that of a child born in the developing world.

Any experiment may be regarded as forming an individual of a 'population' of experiments which might be performed under the same conditions. A series of experiments is a sample drawn from this population.
Now any series of experiments is only of value in so far as it enables us to form a judgment as to the statistical constants of the population to which the experiments belong. In a great number of cases the question finally turns on the value of a mean, either directly, or as the mean difference between the two qualities.
If the number of experiments be very large, we may have precise information as to the value of the mean, but if our sample be small, we have two sources of uncertainty:— (I) owing to the 'error of random sampling' the mean of our series of experiments deviates more or less widely from the mean of the population, and (2) the sample is not sufficiently large to determine what is the law of distribution of individuals.

As a great man’s influence never ends, so also there is no definite finality, no end, to a great survey; it runs along for centuries, ever responsive to the strain of the increasing needs of a growing population and an enlarging domain.

As agonizing a disease as cancer is, I do not think it can be said that our civilization is threatened by it. … But a very plausible case can be made that our civilization is fundamentally threatened by the lack of adequate fertility control. Exponential increases of population will dominate any arithmetic increases, even those brought about by heroic technological initiatives, in the availability of food and resources, as Malthus long ago realized.

Asian Homo erectus died without issue and does not enter our immediate ancestry (for we evolved from African populations); Neanderthal people were collateral cousins, perhaps already living in Europe while we emerged in Africa... In other words, we are an improbable and fragile entity, fortunately successful after precarious beginnings as a small population in Africa, not the predictable end result of a global tendency. We are a thing, an item of history, not an embodiment of general principles.

Before the introduction of the Arabic notation, multiplication was difficult, and the division even of integers called into play the highest mathematical faculties. Probably nothing in the modern world could have more astonished a Greek mathematician than to learn that, under the influence of compulsory education, the whole population of Western Europe, from the highest to the lowest, could perform the operation of division for the largest numbers. This fact would have seemed to him a sheer impossibility. … Our modern power of easy reckoning with decimal fractions is the most miraculous result of a perfect notation.

Biology is a science of three dimensions. The first is the study of each species across all levels of biological organization, molecule to cell to organism to population to ecosystem. The second dimension is the diversity of all species in the biosphere. The third dimension is the history of each species in turn, comprising both its genetic evolution and the environmental change that drove the evolution. Biology, by growing in all three dimensions, is progressing toward unification and will continue to do so.

Birds ... are sensitive indicators of the environment, a sort of “ecological litmus paper,” ... The observation and recording of bird populations over time lead inevitably to environmental awareness and can signal impending changes.

Children are one third of our population and all our future.

Differences between individuals are the raw materials for evolutionary change and for the evolution of adaptations, yet of course most physiologists treat these differences as noise that is to be filtered out. From the standpoint of physiological ecology, the traditional emphasis of physiologists on central tendencies rather than on variance has some unhappy consequences. Variation is not just noise; it is also the stuff of evolution and a central attribute of living systems. The physiological differences between individuals in the same species or population, and also the patterns of variation in different groups, must not be ignored.

Every living thing is a sort of imperialist, seeking to transform as much as possible of its environment into itself and its seed. When we compare the (present) human population of the globe with… that of former times, we see that “chemical imperialism” has been… the main end to which human intelligence has been devoted.

Excessive and prolonged use of tobacco, especially cigarettes, seems to be an important factor in the induction of bronchiogenic carcinoma. Among 605 men with bronchiogenic carcinoma, other than adenocarcinoma, 96.5 per cent were moderately heavy to chain smokers for many years, compared with 73.7 per cent among the general male hospital population without cancer. Among the cancer group 51.2 per cent were excessive or chain smokers compared to 19.1 per cent in the general hospital group without cancer.
[Co-author with Evarts Ambrose Graham]

Famine seems to be the last, the most dreadful resource of nature. The power of population is so superior to the power in the earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction; and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague, advance in terrific array, and sweep off their thousands and ten thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow, levels the population with the food of the world.

Fertilization of mammalian eggs is followed by successive cell divisions and progressive differentiation, first into the early embryo and subsequently into all of the cell types that make up the adult animal. Transfer of a single nucleus at a specific stage of development, to an enucleated unfertilized egg, provided an opportunity to investigate whether cellular differentiation to that stage involved irreversible genetic modification. The first offspring to develop from a differentiated cell were born after nuclear transfer from an embryo-derived cell line that had been induced to became quiescent. Using the same procedure, we now report the birth of live lambs from three new cell populations established from adult mammary gland, fetus and embryo. The fact that a lamb was derived from an adult cell confirms that differentiation of that cell did not involve the irreversible modification of genetic material required far development to term. The birth of lambs from differentiated fetal and adult cells also reinforces previous speculation that by inducing donor cells to became quiescent it will be possible to obtain normal development from a wide variety of differentiated cells.
[Co-author of paper announcing the cloned sheep, ‘Dolly’.]

Finally in a large population, divided and subdivided into partially isolated local races of small size, there is a continually shifting differentiation among the latter (intensified by local differences in selection but occurring under uniform and static conditions) which inevitably brings about an indefinitely continuing, irreversible, adaptive, and much more rapid evolution of the species. Complete isolation in this case, and more slowly in the preceding, originates new species differing for the most part in nonadaptive parallel orthogenetic lines, in accordance with the conditions. It is suggested, in conclusion, that the differing statistical situations to be expected among natural species are adequate to account for the different sorts of evolutionary processes which have been described, and that, in particular, conditions in nature are often such as to bring about the state of poise among opposing tendencies on which an indefinitely continuing evolutionary process depends.

For the environmentalists, The Space Option is the ultimate environmental solution. For the Cornucopians, it is the technological fix that they are relying on. For the hard core space community, the obvious by-product would be the eventual exploration and settlement of the solar system. For most of humanity however, the ultimate benefit is having a realistic hope in a future with possibilities.... If our species does not soon embrace this unique opportunity with sufficient commitment, it may miss its one and only chance to do so. Humanity could soon be overwhelmed by one or more of the many challenges it now faces. The window of opportunity is closing as fast as the population is increasing. Our future will be either a Space Age or a Stone Age.

Forests … are in fact the world’s air-conditioning system—the very lungs of the planet—and help to store the largest body of freshwater on the planet … essential to produce food for our planet’s growing population. The rainforests of the world also provide the livelihoods of more than a billion of the poorest people on this Earth… In simple terms, the rainforests, which encircle the world, are our very life-support system—and we are on the verge of switching it off.

Hospitals are only an intermediate stage of civilization, never intended ... to take in the whole sick population. May we hope that the day will come ... when every poor sick person will have the opportunity of a share in a district sick-nurse at home.

How have people come to be taken in by The Phenomenon of Man? Just as compulsory primary education created a market catered for by cheap dailies and weeklies, so the spread of secondary and latterly of tertiary education has created a large population of people, often with well-developed literary and scholarly tastes who have been educated far beyond their capacity to undertake analytical thought … [The Phenomenon of Man] is written in an all but totally unintelligible style, and this is construed as prima-facie evidence of profundity.

I do not think that, practically or morally, we can defend a policy of saving every distinctive local population of organisms. I can cite a good rationale for the preservation of species, for each species is a unique and separate natural object that, once lost, can never be reconstituted. But subspecies are distinctive local populations of species with broader geographic range. Subspecies are dynamic, interbreedable, and constantly changing: what then are we saving by declaring them all inviolate?

I have no doubt that the fundamental problem the planet faces is the enormous increase in the human population. You see it overrunning everywhere. Places that were very remote when I went there 50 years ago are now overrun.

I have now said enough to show you that it is indispensable for this country to have a scientific education in connexion with manufacturers, if we wish to outstrip the intellectual competition which now, happily for the world, prevails in all departments of industry. As surely as darkness follows the setting of the sun, so surely will England recede as a manufacturing nation, unless her industrial population become much more conversant with science than they are now.

I think every child born on this planet up to the age of about four or five is fascinated by the natural world. If they aren’t it’s because we deprive them of the opportunity. Over half the world’s population is urbanised and the thought that some children may grow up not looking at a pond or knowing how plants grow is a terrible thing. If you lose that delight and joy and intoxication, you’ve lost something hugely precious.

I was suffering from a sharp attack of intermittent fever, and every day during the cold and succeeding hot fits had to lie down for several hours, during which time I had nothing to do but to think over any subjects then particularly interesting me. One day something brought to my recollection Malthus's 'Principles of Population', which I had read about twelve years before. I thought of his clear exposition of 'the positive checks to increase'—disease, accidents, war, and famine—which keep down the population of savage races to so much lower an average than that of more civilized peoples. It then occurred to me that these causes or their equivalents are continually acting in the case of animals also; and as animals usually breed much more rapidly than does mankind, the destruction every year from these causes must be enormous in order to keep down the numbers of each species, since they evidently do not increase regularly from year to year, as otherwise the world would long ago have been densely crowded with those that breed most quickly. Vaguely thinking over the enormous and constant destruction which this implied, it occurred to me to ask the question, Why do some die and some live? The answer was clearly, that on the whole the best fitted live. From the effects of disease the most healthy escaped; from enemies, the strongest, swiftest, or the most cunning; from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain—that is, the fittest would survive.
[The phrase 'survival of the fittest,' suggested by the writings of Thomas Robert Malthus, was expressed in those words by Herbert Spencer in 1865. Wallace saw the term in correspondence from Charles Darwin the following year, 1866. However, Wallace did not publish anything on his use of the expression until very much later, and his recollection is likely flawed.]

If Darwin were alive today the insect world would delight and astound him with its impressive verification of his theories of the survival of the fittest. Under the stress of intensive chemical spraying the weaker members of the insect populations are being weeded out… . Only the strong and fit remain to defy our efforts to control them.

If new species arise very rapidly in small, peripherally isolated local populations, then the great expectation of insensibly graded fossil sequences is a chimera. A new species does not evolve in the area of its ancestors; it does not arise from the slow transformation of all its forbears.
co-author with Niles Eldridge (palaeontologist, 1943- )

If one small and odd lineage of fishes had not evolved fins capable of bearing weight on land (though evolved for different reasons in lakes and seas,) terrestrial vertebrates would never have arisen. If a large extraterrestrial object—the ultimate random bolt from the blue—had not triggered the extinction of dinosaurs 65 million years ago, mammals would still be small creatures, confined to the nooks and crannies of a dinosaur's world, and incapable of evolving the larger size that brains big enough for self-consciousness require. If a small and tenuous population of protohumans had not survived a hundred slings and arrows of outrageous fortune (and potential extinction) on the savannas of Africa, then Homo sapiens would never have emerged to spread throughout the globe. We are glorious accidents of an unpredictable process with no drive to complexity, not the expected results of evolutionary principles that yearn to produce a creature capable of understanding the mode of its own necessary construction.

If the earth’s population continues to double every 50 years (as it is now doing) then by 2550 A.D. it will have increased 3,000-fold. … by 2800 A.D., it would reach 630,000 billion! Our planet would have standing room only, for there would be only two-and-a-half square feet per person on the entire land surface, including Greenland and Antarctica. In fact, if the human species could be imagined as continuing to multiply further at the same rate, by 4200 A.D. the total mass of human tissue would be equal to the mass of the earth.

If the question were, “What ought to be the next objective in science?” my answer would be the teaching of science to the young, so that when the whole population grew up there would be a far more general background of common sense, based on a knowledge of the real meaning of the scientific method of discovering truth.

In man, population structure reaches its greatest complexity. Mankind—the human species, Homo sapiens—is the most inclusive Mendelian population, one which inhabits nearly the whole globe.

In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be, preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work; but I was so anxious to avoid prejudice, that I determined not for some time to write even the briefest sketch of it.

In order to drive the individuals towards reproduction, sexuality had therefore to be associated with some other devices. Among these was pleasure. … Thus pleasure appears as a mere expedient to push individuals to indulge in sex and therefore to reproduce. A rather successful expedient indeed as judged by the state of the world population.

In summary, very large populations may differentiate rapidly, but their sustained evolution will be at moderate or slow rates and will be mainly adaptive. Populations of intermediate size provide the best conditions for sustained progressive and branching evolution, adaptive in its main lines, but accompanied by inadaptive fluctuations, especially in characters of little selective importance. Small populations will be virtually incapable of differentiation or branching and will often be dominated by random inadaptive trends and peculiarly liable to extinction, but will be capable of the most rapid evolution as long as this is not cut short by extinction.

In the early days of dealing with climate change, I wouldn’t go out on a limb one way or another, because I don’t have the qualifications there. But I do have the qualifications to measure the scientific community and see what the consensus is about climate change. I remember the moment when I suddenly thought it was incontrovertible. There was a lecture given by a distinguished American expert in atmospheric science and he showed a series of graphs about the temperature changes in the upper atmosphere. He plotted time against population growth and industrialisation. It was incontrovertible, and once you think it’s really totally incontrovertible, then you have a responsibility to say so.

Is not Cuvier the great poet of our era? Byron has given admirable expression to certain moral conflicts, but our immortal naturalist has reconstructed past worlds from a few bleached bones; has rebuilt cities, like Cadmus, with monsters’ teeth; has animated forests with all the secrets of zoology gleaned from a piece of coal; has discovered a giant population from the footprints of a mammoth.

Isolating mechanisms are biological properties of individuals that prevent the interbreeding of populations that are actually or potentially sympatric.

It is clear that we cannot go up another two orders of magnitude as we have climbed the last five. If we did, we should have two scientists for every man, woman, child, and dog in the population, and we should spend on them twice as much money as we had. Scientific doomsday is therefore less than a century distant.

It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination.

It is popular to believe that the age of the individual and, above all, of the free individual, is past in science. There are many administrators of science and a large component of the general population who believe that mass attacks can do anything, and even that ideas are obsolete. Behind this drive to the mass attack there are a number of strong psychological motives. Neither the public or the big administrator has too good an understanding of the inner continuity of science, but they both have seen its world-shaking consequences, and they are afraid of it. Both of them wish to decerebrate the scientist, even as the Byzantine State emasculated its civil servants. Moreover, the great administrator who is not sure of his own intellectual level can aggrandize himself only by cutting his scientific employees down to size.

It may be argued that to know one kind of beetle is to know them all. But a species is not like a molecule in a cloud of molecules—it is a unique population.

It may be argued that to know one kind of beetle is to know them all. But a species is not like a molecule in a cloud of molecules—it is a unique population.

It will be noticed that the fundamental theorem proved above bears some remarkable resemblances to the second law of thermodynamics. Both are properties of populations, or aggregates, true irrespective of the nature of the units which compose them; both are statistical laws; each requires the constant increase of a measurable quantity, in the one case the entropy of a physical system and in the other the fitness, measured by m, of a biological population. As in the physical world we can conceive the theoretical systems in which dissipative forces are wholly absent, and in which the entropy consequently remains constant, so we can conceive, though we need not expect to find, biological populations in which the genetic variance is absolutely zero, and in which fitness does not increase. Professor Eddington has recently remarked that “The law that entropy always increases—the second law of thermodynamics—holds, I think, the supreme position among the laws of nature.” It is not a little instructive that so similar a law should hold the supreme position among the biological sciences. While it is possible that both may ultimately be absorbed by some more general principle, for the present we should note that the laws as they stand present profound differences—-(1) The systems considered in thermodynamics are permanent; species on the contrary are liable to extinction, although biological improvement must be expected to occur up to the end of their existence. (2) Fitness, although measured by a uniform method, is qualitatively different for every different organism, whereas entropy, like temperature, is taken to have the same meaning for all physical systems. (3) Fitness may be increased or decreased by changes in the environment, without reacting quantitatively upon that environment. (4) Entropy changes are exceptional in the physical world in being irreversible, while irreversible evolutionary changes form no exception among biological phenomena. Finally, (5) entropy changes lead to a progressive disorganization of the physical world, at least from the human standpoint of the utilization of energy, while evolutionary changes are generally recognized as producing progressively higher organization in the organic world.

Judged superficially, a progressive saturation of the germ plasm of a species with mutant genes a majority of which are deleterious in their effects is a destructive process, a sort of deterioration of the genotype which threatens the very existence of the species and can finally lead only to its extinction. The eugenical Jeremiahs keep constantly before our eyes the nightmare of human populations accumulating recessive genes that produce pathological effects when homozygous. These prophets of doom seem to be unaware of the fact that wild species in the state of nature fare in this respect no better than man does with all the artificality of his surroundings, and yet life has not come to an end on this planet. The eschatological cries proclaiming the failure of natural selection to operate in human populations have more to do with political beliefs than with scientific findings.

Laws alone can not secure freedom of expression; in order that every man present his views without penalty there must be spirit of tolerance in the entire population.

Males do not represent two discrete populations, heterosexual and homosexual.

Man is still by instinct a predatory animal given to devilish aggression.
The discoveries of science have immensely increased productivity of material things. They have increased the standards of living and comfort. They have eliminated infinite drudgery. They have increased leisure. But that gives more time for devilment.
The work of science has eliminated much disease and suffering. It has increased the length of life. That, together with increase in productivity, has resulted in vastly increased populations. Also it increased the number of people engaged in devilment.

Methods of fishing are becoming more and more efficient, but the whole fishing industry is based on the exploitation of a wild population. This is almost a prehistoric concept on land, but it has never been questioned at sea.

Most discussions of the population crisis lead logically to zero population growth as the ultimate goal, because any growth rate, if continued, will eventually use up the earth... Turning to the actual measures taken we see that the very use of family planning as the means for implementing population policy poses serious but unacknowledged limits the intended reduction in fertility. The family-planning movement, clearly devoted to the improvement and dissemination of contraceptive devices, states again and again that its purpose is that of enabling couples to have the number of children they want.
With the publication of this article 'zero population growth' and the acronym 'ZPG' came into general use.

Mutations and chromosomal changes arise in every sufficiently studied organism with a certain finite frequency, and thus constantly and unremittingly supply the raw materials for evolution. But evolution involves something more than origin of mutations. Mutations and chromosomal changes are only the first stage, or level, of the evolutionary process, governed entirely by the laws of the physiology of individuals. Once produced, mutations are injected in the genetic composition of the population, where their further fate is determined by the dynamic regularities of the physiology of populations. A mutation may be lost or increased in frequency in generations immediately following its origin, and this (in the case of recessive mutations) without regard to the beneficial or deleterious effects of the mutation. The influences of selection, migration, and geographical isolation then mold the genetic structure of populations into new shapes, in conformity with the secular environment and the ecology, especially the breeding habits, of the species. This is the second level of the evolutionary process, on which the impact of the environment produces historical changes in the living population.

No despot ever flung forth his legions to die in foreign conquest, no privilege-ruled nation ever erupted across its borders, to lock in death embrace with another, but behind them loomed the driving power of a population too large for its boundaries and its natural resources.

Nowadays everyone knows that the US is the world’s biggest polluter, and that with only one 20th of the world’s population it produces a quarter of its greenhouse gas emissions. But the US government, in an abdication of leadership of epic proportions, is refusing to take the problem seriously. … Emissions from the US are up 14% on those in 1990 and are projected to rise by a further 12% over the next decade.

One of the most disturbing ways that climate change is already playing out is through what ecologists call “mismatch” or “mistiming.” This is the process whereby warming causes animals to fall out of step with a critical food source, particularly at breeding times, when a failure to find enough food can lead to rapid population losses.

Our civilization is an engineering civilization, and the prosperous life of the large population, which our earth now supports has become possible only by the work of the engineer. Engineering, however, is the application of science to the service of man, and so to-day science is the foundation, not only of our prosperity, but of our very existence, and thus necessarily has become the dominant power in our human society.

Our contemporary culture, primed by population growth and driven by technology, has created problems of environmental degradation that directly affect all of our senses: noise, odors and toxins which bring physical pain and suffering, and ugliness, barrenness, and homogeneity of experience which bring emotional and psychological suffering and emptiness. In short, we are jeopardizing our human qualities by pursuing technology as an end rather than a means. Too often we have failed to ask two necessary questions: First, what human purpose will a given technology or development serve? Second, what human and environmental effects will it have?

Our emphasis on science has resulted in an alarming rise in world populations, the demand and ever-increasing emphasis of science to improve their standards and maintain their vigor. I have been forced to the conclusion that an over-emphasis of science weakens character and upsets life's essential balance.

Our lifetime may be the last that will be lived out in a technological society. If the world continues to behave as stupidly as it has behaved in the past, we are going to have an increase in population, an increase in violence. We will try to support the population by ripping up earth’s resources, producing pollution at a greater and greater rate, ending, perhaps, in a nuclear war. The earth will have its oil burnt up, most of its most easily available coal used up, its metals distributed thinly over the entire world. We simply won’t have the material basis to build up another technological civilization. The greater the population, the greater the pressure on technology to produce things. Also, there is a great deal of pressure to produce things that don’t directly relate to the quantity of people in the world, but are useless, energy wasting. Socrates is reported to have looked over a bazaar in great wonder and said, “How very many things there are that I do not need.” There are a great many things that we don’t need.

Overdrafts on aquifers are one reason some of our geologist colleagues are convinced that water shortages will bring the human population explosion to a halt. There are substitutes for oil; there is no substitute for fresh water.

Population stabilization policies are a must for sustainable food, health, and livelihood security in many developing countries. If population policies go wrong, nothing else will have a chance to succeed.

Population, when unchecked, goes on doubling itself every twenty-five years, or increases in a geometrical ratio. … The means of subsistence, under circumstances the most favorable to human industry, could not possibly be made to increase faster than in an arithmetical ratio.

Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will show the immensity of the first power in comparison of the second.

Populations of bacteria live in the spumes of volcanic thermal vents on the ocean floor, multiplying in water above the boiling point. And far beneath Earth’s surface, to a depth of 2 miles (3.2 km) or more, dwell the SLIMES (subsurface lithoautotrophic microbial ecosystems), unique assemblages of bacteria and fungi that occupy pores in the interlocking mineral grains of igneous rock and derive their energy from inorganic chemicals. The SLIMES are independent of the world above, so even if all of it were burned to a cinder, they would carry on and, given enough time, probably evolve new life-forms able to re-enter the world of air and sunlight.

Producing food for 6.2 billion people, adding a population of 80 million more a year, is not simple. We better develop an ever improved science and technology, including the new biotechnology, to produce the food that’s needed for the world today. In response to the fraction of the world population that could be fed if current farmland was convered to organic-only crops: “We are 6.6 billion people now. We can only feed 4 billion. I don’t see 2 billion volunteers to disappear.” In response to extreme critics: “These are utopian people that live on Cloud 9 and come into the third world and cause all kinds of confusion and negative impacts on the developing countries.”

Quantitative work shows clearly that natural selection is a reality, and that, among other things, it selects Mendelian genes, which are known to be distributed at random through wild populations, and to follow the laws of chance in their distribution to offspring. In other words, they are an agency producing variation of the kind which Darwin postulated as the raw material on which selection acts.

Taking … the mathematical faculty, probably fewer than one in a hundred really possess it, the great bulk of the population having no natural ability for the study, or feeling the slightest interest in it*. And if we attempt to measure the amount of variation in the faculty itself between a first-class mathematician and the ordinary run of people who find any kind of calculation confusing and altogether devoid of interest, it is probable that the former could not be estimated at less than a hundred times the latter, and perhaps a thousand times would more nearly measure the difference between them.
[* This is the estimate furnished me by two mathematical masters in one of our great public schools of the proportion of boys who have any special taste or capacity for mathematical studies. Many more, of course, can be drilled into a fair knowledge of elementary mathematics, but only this small proportion possess the natural faculty which renders it possible for them ever to rank high as mathematicians, to take any pleasure in it, or to do any original mathematical work.]

Technology made large populations possible; large populations now make technology indispensable.

The advance of technology, like the growth of population and industry, has also been proceeding exponentially.

The assumption we have made … is that marriages and the union of gametes occur at random. The validity of this assumption may now be examined. “Random mating” obviously does not mean promiscuity; it simply means, as already explained above, that in the choice of mates for marriage there is neither preference for nor aversion to the union of persons similar or dissimilar with respect to a given trait or gene. Not all gentlemen prefer blondes or brunettes. Since so few people know what their blood type is, it is even safer to say that the chances of mates being similar or dissimilar in blood type are determined simply by the incidence of these blood types in a given Mendelian population.
[Co-author with Theodosius Dobzhansky]

The assumptions of population thinking are diametrically opposed to those of the typologist. The populationist stresses the uniqueness of everything in the organic world. What is true for the human species,–that no two individuals are alike, is equally true for all other species of animals and plants ... All organisms and organic phenomena are composed of unique features and can be described collectively only in statistical terms. Individuals, or any kind of organic entities, form populations of which we can determine the arithmetic mean and the statistics of variation. Averages are merely statistical abstractions, only the individuals of which the populations are composed have reality. The ultimate conclusions of the population thinker and of the typologist are precisely the opposite. For the typologist, the type (eidos) is real and the variation. an illusion, while for the populationist the type (average) is an abstraction and only the variation is real. No two ways of looking at nature could be more different.

The century of biology upon which we are now well embarked is no matter of trivialities. It is a movement of really heroic dimensions, one of the great episodes in man’s intellectual history. The scientists who are carrying the movement forward talk in terms of nucleo-proteins, of ultracentrifuges, of biochemical genetics, of electrophoresis, of the electron microscope, of molecular morphology, of radioactive isotopes. But do not be misled by these horrendous terms, and above all do not be fooled into thinking this is mere gadgetry. This is the dependable way to seek a solution of the cancer and polio problems, the problems of rheumatism and of the heart. This is the knowledge on which we must base our solution of the population and food problems. This is the understanding of life.

The concepts and methods on which the classification of hominid taxa is based do not differ in principle from those used for other zoological taxa. Indeed, the classification of living human populations or of samples of fossil hominids is a branch of animal taxonomy.

The cutting of primeval forest and other disasters, fueled by the demands of growing human populations, are the overriding threat to biological diversity everywhere. (1992)

The foundations of population genetics were laid chiefly by mathematical deduction from basic premises contained in the works of Mendel and Morgan and their followers. Haldane, Wright, and Fisher are the pioneers of population genetics whose main research equipment was paper and ink rather than microscopes, experimental fields, Drosophila bottles, or mouse cages. Theirs is theoretical biology at its best, and it has provided a guiding light for rigorous quantitative experimentation and observation.

The future of mankind is going to be decided within the next two generations, and there are two absolute requisites: We must aim at a stable-state society [with limited population growth] and the destruction of nuclear stockpiles. … Otherwise I don't see how we can survive much later than 2050.

The introduction of men into the lying in chamber in place of female attendants, has increased the suffering and dangers of childbearing women, and brought multiplied injuries and fatalities upon mothers and children; it violates the sensitive feelings of husbands and wives and causes an untold amount of domestic misery. The unlimited intimacy between a male profession and the female population silently and effectually wears away female delicacy and professional morality, and tends probably more than any other cause in existence, to undermine the foundation of public virtue.

The key to understanding overpopulation is not population density but the numbers of people in an area relative to its resources and the capacity of the environment to sustain human activities; that is, to the area’s carrying capacity. When is an area overpopulated? When its population can’t be maintained without rapidly depleting nonrenewable resources…. By this standard, the entire planet and virtually every nation is already vastly overpopulated.

The late Alan Gregg pointed out that human population growth within the ecosystem was closely analogous to the growth of malignant tumor cells within an organism: that man was acting like a cancer on the biosphere. The multiplication of human numbers certainly seems wild and uncontrolled… Four million a month—the equivalent of the population of Chicago… We seem to be doing all right at the moment; but if you could ask cancer cells, I suspect they would think they were doing fine. But when the organism dies, so do they; and for our own, selfish, practical, utilitarian reasons, I think we should be careful about how we influence the rest of the ecosystem.

The maintenance of biological diversity requires special measures that extend far beyond the establishment of nature reserves. Several reasons for this stand out. Existing reserves have been selected according to a number of criteria, including the desire to protect nature, scenery, and watersheds, and to promote cultural values and recreational opportunities. The actual requirements of individual species, populations, and communities have seldom been known, nor has the available information always been employed in site selection and planning for nature reserves. The use of lands surrounding nature reserves has typically been inimical to conservation, since it has usually involved heavy use of pesticides, industrial development, and the presence of human settlements in which fire, hunting, and firewood gathering feature as elements of the local economy.

The National Health Service is rotting before our eyes, with a lack of political will to make the tough choices for a first-class service for an ever more demanding population.

The next decade will perhaps raise us a step above despair to a cleaner, clearer wisdom and biology cannot fail to help in this. As we become increasingly aware of the ethical problems raised by science and technology, the frontiers between the biological and social sciences are clearly of critical importance—in population density and problems of hunger, psychological stress, pollution of the air and water and exhaustion of irreplaceable resources.

The only level of the hierarchy [of biological communities] that is both necessary and sufficient to meet all objectives is the ecosystem or some higher-level approach. The strategy selected should not only ensure the conservation of spotted owls, but all the intricate linkages that are associated with natural populations of spotted owls in naturally functioning ecosystems. Many of these are as yet unknown.

The origin of species is therefore simply the evolution of some difference—any difference at all—that prevents the production of fertile hybrids between populations under natural conditions.

The problem [evolution] presented itself to me, and something led me to think of the positive checks described by Malthus in his Essay on Population, a work I had read several years before, and which had made a deep and permanent impression on my mind. These checks—war, disease, famine, and the like—must, it occurred to me, act on animals as well as man. Then I thought of the enormously rapid multiplication of animals, causing these checks to be much more effective in them than in the case of man; and while pondering vaguely on this fact, there suddenly flashed upon me the idea of the survival of the fittest—that the individuals removed by these checks must be on the whole inferior to those that survived. I sketched the draft of my paper … and sent it by the next post to Mr. Darwin.

The prodigious waste of human life occasioned by this perpetual struggle for room and food, was more than supplied by the mighty power of population, acting, in some degree, unshackled, from the constant habit of emigration.

The proof given by Wright, that non-adaptive differentiation will occur in small populations owing to “drift,” or the chance fixation of some new mutation or recombination, is one of the most important results of mathematical analysis applied to the facts of neo-mendelism. It gives accident as well as adaptation a place in evolution, and at one stroke explains many facts which puzzled earlier selectionists, notably the much greater degree of divergence shown by island than mainland forms, by forms in isolated lakes than in continuous river-systems.

The rapid growth of industry, the ever increasing population and the imperative need for more varied, wholesome and nourishing foodstuff makes it all the more necessary to exhaust every means at our command to fill the empty dinner pail, enrich our soils, bring greater wealth and influence to our beautiful South land, which is synonymous to a healthy, happy and contented people.

The ratio between supervisory and producing personnel is always highest where the intellectuals are in power. In a Communist country it takes half the population to supervise the other half.

The reduced variability of small populations is not always due to accidental gene loss, but sometimes to the fact that the entire population was started by a single pair or by a single fertilized female. These “founders” of the population carried with them only a very small proportion of the variability of the parent population. This “founder” principle sometimes explains even the uniformity of rather large populations, particularly if they are well isolated and near the borders of the range of the species.

The rich can pay when they have to pay [for medical care]. The poor receive free treatment from skilled specialists and can go, when necessary, to hospitals free of charge. But between seventy-five and ninety per cent. of our population, that which constitutes our very backbone, find it difficult to be relieved from the intolerable burden of illness.

The Science of crystallography has been accused of being overrun with women and has been likened to 'intellectual knitting.' ... The international figure for women in crystallography in 1981 was 14 per cent of the population of 8,174 entries in the World Directory of Crystallographers.

The solutions put forth by imperialism are the quintessence of simplicity...When they speak of the problems of population and birth, they are in no way moved by concepts related to the interests of the family or of society...Just when science and technology are making incredible advances in all fields, they resort to technology to suppress revolutions and ask the help of science to prevent population growth. In short, the peoples are not to make revolutions, and women are not to give birth. This sums up the philosophy of imperialism.

The study of fish in the sea may be the most necessary of all our oceanographic researches because we shall increasingly be made to turn to the sea as a vast food producer by the increase in the population of the world.

The technologies which have had the most profound effects on human life are usually simple. A good example of a simple technology with profound historical consequences is hay. ... It was hay that allowed populations to grow and civilizations to flourish among the forests of Northern Europe. Hay moved the greatness of Rome to Paris and London, and later to Berlin and Moscow and New York.
[The year-round growth of green grass in the Mediterranean climate meant that hay was not needed by the Romans. North of the Alps, hay maintained horses and oxen and thus their motive power, and productivity.]

The technologies which have had the most profound effects on human life are usually simple. A good example of a simple technology with profound historical consequences is hay. Nobody knows who invented hay, the idea of cutting grass in the autumn and storing it in large enough quantities to keep horses and cows alive through the winter. All we know is that the technology of hay was unknown to the Roman Empire but was known to every village of medieval Europe. Like many other crucially important technologies, hay emerged anonymously during the so-called Dark Ages. According to the Hay Theory of History, the invention of hay was the decisive event which moved the center of gravity of urban civilization from the Mediterranean basin to Northern and Western Europe. The Roman Empire did not need hay because in a Mediterranean climate the grass grows well enough in winter for animals to graze. North of the Alps, great cities dependent on horses and oxen for motive power could not exist without hay. So it was hay that allowed populations to grow and civilizations to flourish among the forests of Northern Europe. Hay moved the greatness of Rome to Paris and London, and later to Berlin and Moscow and New York. ... Great inventions like hay and printing, whatever their immediate social costs may be, result in a permanent expansion of our horizons, a lasting acquisition of new territory for human bodies and minds to cultivate.

The theory here developed is that mega-evolution normally occurs among small populations that become preadaptive 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, inadaptive differentiation and random fixation of mutations occur. Among many such inadaptive lines one or a few are preadaptive, 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.

The world of organisms, of animals and plants, is built up of individuals. I like to think, then, of natural history as the study of life at the level of the individual—of what plants and animals do, how they react to each other and their environment, how they are organized into larger groupings like populations and communities.

There are three times as many people in the world as when I started making television programs 56 years ago. It is frightening. We can’t go on as we have been. We are seeing the consequences in terms of ecology, pollution, space and food production.

There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago.

There’s no evolution of single individuals. Evolution is the property of populations.

We are a plague on the Earth. It’s coming home to roost over the next 50 years or so. It’s not just climate change; it’s sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now.

We have before us the restoration of that ancient land whose name was a synonym for abundance, prosperity, and grandeur for many generations. Records as old as those of Egypt and as well attested tell of fertile lands and teeming populations, mighty kings and warriors, sages and wise men, over periods of thousands of years. ... A land such as this is worth resuscitating. Once we have apprehended the true cause of its present desolate and abandoned condition, we are on our way to restoring it to its ancient fertility. A land which so readily responded to ancient science, and gave a return which sufficed for the maintenance of a Persian Court in all its splendor, will surely respond to the efforts of modern science and return manifold the money and talent spent on its regeneration.

We should look upon agriculture not just as a food-producing machine for the urban population, but as the major source of skilled and remunerative employment and a hub for global outsourcing.

We talk about our high standard of living in this country. What we have is a high standard of work. Usually the peaks of civilization have been periods when a large proportion of the population had time to live. I don’t think we’re doing this today. I think the people who could live are still spending their time and supplementary resources on making a living.

Were I to make the announcement and to run, the reasons I would run is because I have a great belief in this country [America]. … There’s more natural resources than any nation in the world; the greatest education population in the world; the greatest technology of any country in the world; the greatest capacity for innovation in the world; and the greatest political system in the world.

What these two sciences of recognition, evolution and immunology, have in common is not found in nonbiological systems such as 'evolving' stars. Such physical systems can be explained in terms of energy transfer, dynamics, causes, and even 'information transfer'. But they do not exhibit repertoires of variants ready for interaction by selection to give a population response according to a hereditary principle. The application of a selective principle in a recognition system, by the way, does not necessarily mean that genes must be involved—it simply means that any state resulting after selection is highly correlated in structure with the one that gave rise to it and that the correlation continues to be propagated. Nor is it the case that selection cannot itself introduce variation. But a constancy or 'memory' of selected events is necessary. If changes occurred so fast that what was selected could not emerge in the population or was destroyed, a recognition system would not survive. Physics proper does not deal with recognition systems, which are by their nature biological and historical systems. But all the laws of physics nevertheless apply to recognition systems.

When the practice of farming spread over the earth, mankind experienced its first population explosion.

When the state is shaken to its foundations by internal or external events, when commerce, industry and all trades shall be at a stand, and perhaps on the brink of ruin; when the property and fortune of all are shaken or changed, and the inhabitants of towns look forward with dread and apprehension to the future, then the agriculturalist holds in his hand the key to the money chest of the rich, and the savings-box of the poor; for political events have not the slightest influence on the natural law, which forces man to take into his system, daily, a certain number of ounces of carbon and nitrogen.
Reflecting on events of 1848.

When there are two independent causes of variability capable of producing in an otherwise uniform population distributions with standard deviations s₁ and s₂, it is found that the distribution, when both causes act together, has a standard deviation vs₁² + s₂². It is therefore desirable in analysing the causes of variability to deal with the square of the standard deviation as the measure of variability. We shall term this quantity the Variance of the normal population to which it refers, and we may now ascribe to the constituent causes fractions or percentages of the total variance which they together produce.

You can stop splitting the atom; you can stop visiting the moon; you can stop using aerosols; you may even decide not to kill entire populations by the use of a few bombs. But you cannot recall a new form of life.

You’ve got to be fairly solemn [about the environment]. I mean the mere notion that there are three times as many people on Earth as there were when I started making television. How can the Earth accommodate them? When people, including politicians, set their faces against looking at the consequences—it’s just unbelievable that anyone could ignore it.