natural-selection

Animals have genes for altruism, and those genes have been selected in the evolution of many creatures because of the advantage they confer for the continuing survival of the species.

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.

It is not the organs__hat is, the character and form of the animal's bodily parts__hat have given rise to its habits and particular structures. It is the habits and manner of life and the conditions in which its ancestors lived that have in the course of time fashioned its bodily form, its organs and qualities.

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 __oup._ 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.

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.

The arms race between [predators] and [prey] is asymmetric, in which success on either side is felt as failure by the other side, but the nature of the success and failure on the two sides is very different. The two sides are 'trying' to do very different things. [Predators] are trying to eat [prey]. [Prey] are not trying to eat [predators], they are trying to avoid being eaten by [predators].From an evolutionary point of view asymmetric arms races are more [likely] to generate highly complex weapons systems.

It is therefore scientifically correct to say that 'natural selection has been proved to be an agent of evolutionary change' - we can, in fact, prove it by doing. But it is totally illegitimate to claim that the discovery of this mechanism - natural selection - proves that the cause of evolution 'was automatic with no room for divine guidance or design'.

He who believes that each being has been created as we now see it, must occasionally have felt surprise when he has met with an animal having habits and structure not at all in agreement.

Evolution has no long-term goal. There is no long-distance target, no final perfection to serve as a criterion for selection, although human vanity cherishes the absurd notion that our species is the final goal of evolution.

People who are depressed at the thought that all our motives are selfish are [confused]. They have mixed up ultimate causation (why something evolved by natural selection) with proximate causation (how the entity works here and now). [A] good way to understand the logic of natural selection is to imagine that genes are agents with selfish motives. [T]he genes have metaphorical motives _ making copies of themselves _ and the organisms they design have real motives. But they are not the same motives. Sometimes the most selfish thing a gene can do is wire unselfish motives into a human brain _ heartfelt, unstinting, deep-in-the-marrow unselfishness. The love of children (who carry one's genes into posterity), a faithful spouse (whose genetic fate is identical to one's own), and friends and allies (who trust you if you're trustworthy) can be bottomless and unimpeachable as far as we humans are concerned (proximate level), even if it is metaphorically self-serving as far as the genes are concerned (ultimate level). Combine this with the common misconception that the genes are a kind of essence or core of the person, and you get a mongrel of Dawkins and Freud: the idea that the metaphorical motives of the genes are the deep, unconscious, ulterior motives of the person. That is an error.

Oxygen flooded into the atmosphere as a pollutant, even a poison, until natural selection shaped living things to thrive on the stuff and, indeed, suffocate without it.

George Williams, the revered evolutionary biologist, describes the natural world as __rossly immoral._ Having no foresight or compassion, natural selection __an honestly be described as a process for maximizing short-sighted selfishness._ On top of all the miseries inflicted by predators and parasites, the members of a species show no pity to their own kind. Infanticide, siblicide, and rape can be observed in many kinds of animals; infidelity is common even in so-called pair-bonded species; cannibalism can be expected in all species that are not strict vegetarians; death from fighting is more common in most animal species than it is in the most violent American cities. Commenting on how biologists used to describe the killing of starving deer by mountain lions as an act of mercy, Williams wrote: __he simple facts are that both predation and starvation are painful prospects for deer, and that the lion's lot is no more enviable. Perhaps biology would have been able to mature more rapidly in a culture not dominated by Judeo-Christian theology and the Romantic tradition. It might have been well served by the First Holy Truth from [Buddha's] Sermon at Benares: __irth is painful, old age is painful, sickness is painful, death is painful...__ As soon as we recognize that there is nothing morally commendable about the products of evolution, we can describe human psychology honestly, without the fear that identifying a __atural_ trait is the same as condoning it. As Katharine Hepburn says to Humphrey Bogart in The African Queen, __ature, Mr. Allnut, is what we are put in this world to rise above.

Nothing at first can appear more difficult to believe than that the more complex organs and instincts should have been perfected, not by means superior to, though analogous with, human reason, but by the accumulation of innumerable slight variations, each good for the individual possessor. Nevertheless, this difficulty, though appearing to our imagination insuperably great, cannot be considered real if we admit the following propositions, namely,_ that gradations in the perfection of any organ or instinct, which we may consider, either do now exist or could have existed, each good of its kind,_ that all organs and instincts are, in ever so slight a degree, variable,_ and, lastly, that there is a struggle for existence leading to the preservation of each profitable deviation of structure or instinct. The truth of these propositions cannot, I think, be disputed.

Things exist either because they have recently come into existence or because they have qualities that made them unlikely to be destroyed in the past.

It looks as if the offspring have eyes so that they can see well (bad, teleological, backward causation), but that's an illusion. The offspring have eyes because their parents' eyes did see well (good, ordinary, forward causation).

It wasn't torpor that kept her - she was often restless to the point of irritability. She simply liked to feel that she was prevented from leaving, that she was needed.

Perhaps the most legitimately dispiriting thing about reciprocal altruism is that it is a misnomer. Whereas with kin selection the "goal" of our genes is to actually help another organism, with reciprocal altruism the goal is that the organism be left under the impression that we've helped; the impression alone is enough to bring the reciprocation.

There was something built into the human brain by natural selection which was once useful, and which now manifests itself as religion.