Rudy Garns's Library tagged Darwin →  View Popular, Search in Google

But contrary to Haidt, this is not a frailty that can be avoided by relying on large, speculative ideas. If history shows anything, it is that acting on the basis of grand theories only makes human behavior even more unreasonable.

Books such as Marc Hauser’s Moral Minds, one of the more impressive of recent applications of Darwinism to ethics, assume that acting morally is a matter of following rules or principles having mainly to do with justice and the prevention of harm. This may seem self-evident to secular social scientists in American universities, but it hardly squares with how most human beings (or most Americans, for that matter) understand morality.

like a tongue with six taste receptors.

Clifford Geertz’s observation: “The Western conception of the person as a bounded, unique, more or less integrated motivational and cognitive universe ... is, however incorrigible it may seem to us, a rather peculiar idea within the context of the world’s cultures.”

Notions of individual responsibility are not prominent in the Iliad, where moral life turns on issues of shame and social recognition; nor do they figure much in many non-Western cultures today.

When “morality” becomes a term of art in a supposedly scientific discipline, there is no longer any difference between good and bad moralities.

functionalist: “Moral systems are interlocking sets of values, virtues, norms, practices, identities, institutions, technologies, and evolved psychological mechanisms that work together to suppress or regulate self-interest and make cooperative societies possible.”

the accumulation of innumerable slight variations, each good for the individual possessor

gradations in the perfection of any organ or instinct

all organs and instincts are, in ever so slight a degree, variable

there is a struggle for existence leading to the preservation of each profitable deviation of structure or instinct

some species have retained the same specific form for very long periods, enormously long as measured by years

time sufficient for any amount of organic change

The number of specimens in all our museums is absolutely as nothing compared with the countless generations of countless species which certainly have existed.

sufficiently constant and distinct from other forms

we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species.

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into   one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

People with just one copy of this gene are 29% less likely to get malaria, while people with two copies enjoy a 93% reduction in risk.

The gene for one kind of cone, which responds most strongly to blue, is found on chromosome 7. The two other kinds, which are sensitive to red and green, are both on the X chromosome. Since men have only one X, a mutation which disables either the red or the green gene will produce red-green colorblindness, while women have a backup copy. This explains why this is almost exclusively a male condition.

having incomparably longer time at her disposal

external and visible characters

Can we wonder, then, that nature's productions should be far 'truer' in character than man's productions; that they should be infinitely better adapted to the most complex conditions of life, and should plainly bear the stamp of far higher workmanship?

We see nothing of these slow changes in progress

In social animals it will adapt the structure of each individual for the benefit of the community;

This depends, not on a struggle for existence, but on a struggle between the males for possession of the females; the result is not death to the unsuccessful competitor, but few or no offspring.

Natural selection can act only by the preservation and accumulation of infinitesimally small inherited modifications, each profitable to the preserved being

with animals and plants a cross between different varieties, or between individuals of the same variety but of another strain, gives vigour and fertility to the offspring; and on the other hand, that close interbreeding diminishes vigour and fertility

no organic being self-fertilises itself for an eternity of generations; but that a cross with another individual is occasionally perhaps at very long intervals -- indispensable.

Intercrossing plays a very important part in nature in keeping the individuals of the same species, or of the same variety, true and uniform in character.

In a confined or isolated area, if not very large, the organic and inorganic conditions of life will generally be in a great degree uniform; so that natural selection will tend to modify all the individuals of a varying species throughout the area in the same manner in relation to the same conditions.

isolation, by checking immigration and consequently competition, will give time for any new variety to be slowly improved;

largeness of area is of more importance

natural selection will always act with extreme slowness

depends on there being places in the polity of nature, which can be better occupied by some of the inhabitants of the country undergoing modification of some kind

this very slow, intermittent action of natural selection accords perfectly well with what geology tells us of the rate and manner at which the inhabitants of this world have changed.

Natural selection acts solely through the preservation of variations in some way advantageous, which consequently endure.

so will the less favoured forms decrease and become rare.

rare species will be less quickly modified or improved within any given period, and they will consequently be beaten in the race for life by the modified descendants of the commoner species.

each new variety or species, during the progress of its formation, will generally press hardest on its nearest kindred, and tend to exterminate them.

varieties, even strongly-marked ones, though having somewhat of the character of species as is shown by the hopeless doubts in many cases how to rank them yet certainly differ from each other far less than do good and distinct species

varieties are species in the process of formation, or are, as I have called them, incipient species.

How, then, does the lesser difference between varieties become augmented into the greater difference between species?

Mere chance, as we may call it, might cause one variety to differ in some character from its parents, and the offspring of this variety again to differ from its parent in the very same character and in a greater degree; but this alone would never account for so habitual and large an amount of difference as that between varieties of the same species and species of the same genus.

the principle of divergence, causing differences, at first barely appreciable, steadily to increase, and the breeds to diverge in character both from each other and from their common parent.

better enabled to seize on many and widely diversified places in the polity of nature, and so be enabled to increase in numbers.

only by its varying descendants seizing on places at present occupied by other animals

organic beings vary at all in the several parts of their organisation

a severe struggle for life

The more diversified in habits and structure the descendants of our carnivorous animal became, the more places they would be enabled to occupy

if variations useful to any organic being do occur

strong principle of inheritance

sexual selection

Sexual selection will also give characters useful to the males alone, in their struggles with other males.

judged of by the general tenour and balance of evidence given in the following chapters

more living beings can be supported on the same area the more they diverge in structure, habits, and constitution

Natural selection, also, leads to divergence of  character

modification of the descendants

In an extremely small area, especially if freely open to immigration, and where the contest between individual and individual must be severe, we always find great diversity in its inhabitants.

Natural selection, as has just been remarked, leads to divergence of character and to much extinction of the less improved and intermediate forms of life.

On the view that each species has been independently created, I can see no explanation of this great fact in the classification of all organic beings; but, to the best of my judgment, it is explained through inheritance and the complex action of natural selection, entailing extinction and divergence of character, as we have seen illustrated in the diagram.

represented by a great tree

in the general economy of any land, the more widely and perfectly the animals and plants are diversified for different habits of life, so will a greater number of individuals be capable of there supporting themselves.

Owing to this struggle for life, any variation, however slight and from whatever cause proceeding, if it be in any degree profitable to an individual of any species, in its infinitely complex relations to other organic beings and to external nature, will tend to the preservation of that individual, and will generally be inherited by its offspring

Natural Selection

all organic beings are exposed to severe competition

dependence of one being on another

success in leaving progeny

there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life.

naturally increases at so high a rate

The condor lays a couple of eggs and the ostrich a score

the real importance of a large number of eggs or seeds is to make up for much destruction at some period of life;

The amount of food for each species of course gives the extreme limit to which each can increase

serving as prey to other animals

Climate plays an important part in determining the average numbers of a species

epidemics

in many cases, a large stock of individuals of the same species, relatively to the numbers of its enemies, is absolutely necessary for its preservation

cattle absolutely determine the existence of the Scotch fir

yet in the long-run the forces are so nicely balanced, that the face of nature remains uniform for long periods of time, though assuredly the merest trifle would often give the victory to one organic being over another

so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!

When we look at the plants and bushes clothing an entangled bank, we are tempted to attribute their proportional numbers and kinds to what we call chance. But how false a view is this!

Throw up a handful of feathers, and all must fall to the ground according to definite laws; but how simple is this problem compared to the action and reaction of the innumerable plants and animals which have determined, in the course of centuries, the proportional numbers and kinds of trees now growing on the old Indian ruins!

But the struggle almost invariably will be most severe between the individuals of the same species, for they frequent the same districts, require the same food, and are exposed to the same dangers

As species of the same genus have usually, though by no means invariably, some similarity in habits and constitution, and always in structure, the struggle will generally be more severe between species of the same genus, when they come into competition with each other, than between species of distinct genera.

the structure of every organic being is related, in the most essential yet often hidden manner, to that of all other organic beings, with which it comes into competition for food or residence, or from which it has to escape, or on which it preys.

I suspect that the chief use of the nutriment in the seed is to favour the growth of the young seedling, whilst struggling with other plants growing vigorously all around.

our ignorance on the mutual relations of all organic beings

each organic being is striving to increase at a geometrical  ratio

struggle for life, and to suffer great destruction

the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.

those relationships across time—the fossil and the modern—might mirror relationships across the landscape, where one species replaced another in the topographical sense. This feature of the animal world suggested some kind of underlying genealogical tree.

the diversification of species on separate islands

all changes in the earth’s surface were the result of a gradual accumulation of many small events. Darwin took this idea, applied it to biology, and turned it into a lasting methodology that lies at the heart of his Origin of Species. For the rest of his life, he remained committed to the concept that many small changes can add up to larger effects.

evolution must be gradual, with no major breaks or discontinuities

mechanism of evolution was natural selection

A diverse population is a necessity

Change on the earth is the result of both, the first step being dominated by randomness, the second by necessity

the object, or target, of selection was primarily the individual as a whole

Darwin was a holist

the dual nature of biological processes.

Darwinism rejects all supernatural phenomena and causations

Darwinism refutes typology

Darwin's theory of natural selection made any invocation of teleology unnecessary

Darwin does away with determinism

Darwin developed a new view of humanity and, in turn, a new anthropocentrism

Darwin provided a scientiflc foundation for ethics

Yes, he established a philosophy of biology by introducing the time factor, by demonstrating the importance of chance and contingency, and by showing that theories in evolutionary biology are based on concepts rather than laws. But furthermore - and this is perhaps Darwin's greatest contribution - he developed a set of new principles that influence the thinking of every person: the living world, through evolution, can be explained without recourse to supernaturalism; essentialism or typology is invalid, and we must adopt population thinking, in which all individuals are unique (vital for education and the refutation of racism); natural selection, applied to social groups, is indeed sufficient to account for the origin and maintenance of altruistic ethical systems; cosmic teleology, an intrinsic process leading life automatically to ever greater perfection, is fallacious, with all seemingly teleological phenomena explicable by purely material processes; and determinism is thus repudiated, which places our fate squarely in our own evolved hands.