Because communities were then much smaller; so that under endogamous conditions whatever vice may beset inbreeding would, generation after generation, be perpetuated and exaggerated without relief.
But if inbreeding was injurious, Natural Selection favoured any family or band that practised Exogamy.
When the amount of inbreeding represented by these blind boys was measured, it proved to be almost identical with the amount represented by the present Kaiser of Germany.
Sometimes by close inbreeding the eugenic process has been hastened.
It is very probable, but not absolutely certain, that inbreeding is harmful.
It is possible that at first, and within limits, inbreeding is not harmful, but becomes such if repeated often.
There is more doubt now about the penalties of inbreeding than there is about the power of savage men to perceive them and try to escape them, if they exist.
The due adjustment of inbreeding and outbreeding is always a difficult problem of policy for breeders of animals.
Inbreeding preserves a type but weakens the stock.
The notion of harm in inbreeding has spread all over the earth.
The evils of inbreeding are so probable as to justify strong prejudice against consanguine marriages.
He thinks that, by natural selection, those groups which practiced inbreeding for any reason died out or were displaced by those who followed the other policy.
Inbreeding maintains the excellence of a breed at the expense of its vigor.
Two dancers, one of each sex, represented this action at Sceaux; and their dance painted it with all the energy and pathos of which it was susceptible.
Would Augustus have declared himself the special patron of a kind of entertainment that had been deficient as to probability and genius?
The Greeks, who probably took their first ideas of this art, as they did of most others, from Egypt, where it was in great esteem and practice, carried it up to a very high pitch.
Its march proceeds from picture to picture, to which, motion gives life.
In painting, life is only imitated; in dancing, it is always the reality itself.
The proofs shown of the perfection of dancing at Athens, and under the reign of Augustus, being incontestable, it is plain that what now passes for the art of dancing, is as yet only in its infancy.
And upon whom were these lively impressions produced?
Since these sons have the three recessive factors, inbreeding of F1 is equivalent to a triple back-cross.
A complementary experiment was made by crossing cherry club vermilion females to wild males and inbreeding the F1 in pairs.
The endless devices of the more ambitious flowers to save their species from degeneracy by close inbreeding through fertilization with their own pollen, alone prove the operation of Mind through them.
Nevertheless, enough cross-fertilized seed is set to save the species from the degeneracy that follows close inbreeding among plants as well as animals.
But if they go further and declare that the subsequent restrictions of inbreeding and the gentile order have arisen independently of relationships, they commit a far greater mistake than Morgan.
A further step for preventing inbreeding is found among the Kamilaroi on the Darling River in New South Wales, where the two original classes are split into four, and every one of these is married as a whole to a certain other class.
Without question, the tribes limiting inbreeding by this progress developed faster and more completely than those retaining the marriage between brothers and sisters as a rule and law.
Enough, the desire to prevent inbreeding again and again demands recognition, but feeling its way quite spontaneously, without a clear conception of the goal.
Moreover, close inbreeding also, as the experiments of stock-breeders show, would tend to produce a surplus of male births, and so would act finally in the same way as the second cause.
Man has an antipathy to incest or close inbreeding which seems to be instinctive.
There is no surer way of maintaining uniformity of type, and an examination of the extended pedigree of almost any famous dog will show how commonly inbreeding is practised.
There is a white blaze on the forehead, in the centre of which should be a clear lozenge-shaped chestnut spot, called the beauty spot, which by inbreeding with other varieties is fast being lost.
Broadly speaking, two methods have been adopted: The method of introducing an outcross to impart new blood, new strength, new character; and the method of inbreeding to retain an approved type.
I will give just one case of inbreedingin our kennels, tried for experiment's sake, as a warning.
The breeder of today has a far easier time than in the early days of the dog when type was not as pronounced or fixed, and when considerable inbreeding of necessity had to be resorted to.
I believe that this inbreeding is productive of excessive nervousness, weakness in physical form, the impairment of breeding functions, and the predisposition to disease in its multiform manifestations.
By the continued inbreeding of the most typical of the sons and daughters of Tom, the present type of the dog was made permanent.
Inbreeding was permitted year after year, as one tom was thought sufficient for the hen turkeys of five or six neighbors.
Of all our domestic fowl, none suffer more from inbreedingthan the turkey.
Close inbreeding soon runs down the vitality of a flock and should be avoided.
Professor Ewart, however, believes that inbreeding is much commoner among wild animals than has usually been conceded, and he holds the opinion that the prepotency so induced has played a considerable part in the origin of species.
In inbreeding the great difficulty of the breeder is to know when to stop.
Pedigrees from wine-growing districts in the centre of Baden; against this it may be taken as proved that inbreeding in itself between the healthy and fit is not harmful.
On the whole with mankind inbreeding is viewed with fear, and justly so, in view of our customary carelessness with regard to the physical and mental conditions of those who contract marriage.
As soon as the stock has become a pure line, inbreeding produces no further weakening.
The result of self-fertilization or of close inbreeding is that the hybrid nature diminishes in degree.
Inbreeding maintains a fineness of breed, but at the cost of its vigor.
The Polynesians must have remarked that inbreeding accentuated the faults in a strain, making for an accumulation of them.
But crossing may be done in a way to develop good qualities, and these may afterward be fixed by careful selection and inbreeding of offspring.
His thirty years of the closest inbreeding have shown no such disastrous effects, but, on the contrary, have produced only good ones.
Where inbreeding is followed, the only disadvantage arises from the fact that all the animals are likely to have the same defects of form, quality and constitution.
The reason for this uniformity is plain, and is found in the origin of the breed in the closest possible inbreeding for thirty years.
A word here about inbreeding will not be out of place.
Inbreeding intensifies and fixes the qualities, be they good or bad.
This is probably one of the most remarkable cases of inbreeding on record, as the breed is also one of the most remarkable.
But where these are all right, the advantage is that inbreeding fixes the features and qualities and secures the establishment of them in a type or breed.
Inbreeding means the reduction of the number of branches in the ancestral tree, and this means the reduction of the number of chances to get variation, be they good or bad.
Unintelligent inbreedingas practiced on many a farm, results in run down stock, not so much from inbreeding as from lack of selection.
It does not necessarily destroy the vitality, but if close inbreeding is practiced long enough, sooner or later some little existing weakness or peculiarity would become intensified and may prove fatal to the strain.
For illustration, suppose we began inbreeding brother and sister with a view of keeping it up indefinitely.