It strongly supports our view of the origin of species by mutationinstead of continuous selection.
But no such proof has been found, and the conclusion seems admissible that the mutation of toad-flaxes ordinarily, if not universally, takes place by a sudden step.
It is manifest that a complete understanding of a mutation depends upon full information upon these points.
The mutation theory gives a clew to the final combination of the two contending ideas.
Laciniate alders seem to have been produced by mutation at sundry times.
In contradiction to this conception the theory of mutation assumes that new species and varieties are produced from existing forms by sudden leaps.
Examples of this obvious and usual practice will be given further on, but it must be pointed out now that by such crosses a single mutation may produce as many novelties as there are available varieties of the same species.
Secondly, hybrids may be produced between a true, new mutation and some of the already existing varieties of the same species.
Thirdly, the question arises, whether the mutation is complete, not only as to the morphologic character, but also as to the hereditary constitution of the mutated individuals.
If not, then the mutation must have been sudden, occurring without visible preparation and without the appearance of intermediates.
Of late the same mutation has occurred in the garden of C.
Whether it is an old variety or a recent mutation it is of course impossible to decide.
Whether these three varieties are of independent, but parallel origin, or are to be considered as due to a single mutation and subsequent crosses is not known, all of them being of ancient origin.
The main apparent advantage of mutation is that it hastens the time in which a new species may arise.
This theory of Mutation has been eagerly seized upon by many botanists.
True, the change itself would be accidental, since the mutation works, according to De Vries, in different directions in the different representatives of the species.
The direction of the mutation may therefore be so as well, at least in animals, and to the extent we shall have to indicate.
Be that as it may, the neo-Darwinians are inclined to admit that the periods of mutation are determinate.
In some ways, genetic mutation acquires the status of a new means for synthesizing new plants and animals, and even new materials.
Meme mutation and spread of a reduced scale, such as the scale of finite artificial languages and limited logical rules, can be described in equations similar to those of genetics.
We find, in short, such evidence of the slow and scarcely sensible mutation of specific forms, as we have a just right to expect to find.
Why does not every collection of fossil remains afford plain evidence of the gradation and mutation of the forms of life?
Majestic turrets, and the stately dome Which, ovaled by the slow but tireless hand Of eons of disintegrating time, Still with impressive aspect rears its brow Defiant of mutation and decay.
Everyone knew that the First-In Scouts were a weird breed, almost a mutation of Terran stock--their reports were rife with strange observations.
And upon closer observation the Terran could see that there was a difference among these ranked skulls, a mutation of coloring from row to row, a softening of outline, perhaps by the wearing of time.
De Vries shows the probability that species go on for long periods showing only fluctuations, and then suddenly take to sporting in the way described, short periods of mutation alternating with long intervals of relative constancy.
Festing Jones first directed my attention to these passages and their bearing on theMutation Theory.
If through a mutation a character appears that is neither advantageous nor disadvantageous, but indifferent, the chance that it may become established in the race is extremely small, although by good luck such a thing may occur rarely.
If through a mutation a character appears that has an injurious effect, however slight this may be, it has practically no chance of becoming established.
In the third figure (c) the other mutationin size is shown.
In the case of eosin eye color no such process as that postulated by Darwin to account for the differences between the sexes was involved; for the single mutation that brought about the change also brought in the dimorphism with it.
The mutation that produces this type of wing is of not infrequent occurrence.
If through a mutation a character appears that has a beneficial influence on the individual, the chance that the individual will survive is increased, not only for itself, but for all of its descendants that come to inherit this character.
What is evil to thee does not subsist in the ruling principle of another; nor yet in any turning and mutation of thy corporeal covering.
All things are changing: and thou thyself art in continuous mutation and in a manner in continuous destruction, and the whole universe too.
If mutation is the symbol for accommodation, growth is the metaphor for assimilation.
Conversion is the sudden mutation of life-attitudes through a reorganization or transformation of the wishes.
The changes that occur in accommodation are frequently not only sudden but revolutionary, as in the mutation of attitudes in conversion.
Things are said figuratively by Mutation when the ordinary order is inverted.
And the cause of the mutation is that the nominative accusative and vocative seem to have a certain relation to one another.
Empedocles affirms that Nature is nothing else but the mixture and separation of the elements; for thus he writes in the first book of his natural philosophy:-- Nature gives neither life nor death, Mutation makes us die or breathe.
In late 1971 there had been a mutation of a minor strain of staphylococcus somewhere in the Andes.
Nothing suffered mutation but my host, who was fairly altered into a gentlewoman, whom I knew to be Dame Quickly, mistress of this tavern in the days of Sir John; and the liquor we were drinking seemed converted into sack and sugar.
Mendelism and mutation theories may have something to say on the subject when these theories have been more fully correlated with the basal principles of selection.
This gives a severe shock to the "Mutation theory," for the other actually wild species with which de Vries experimented showed no "mutations" but yielded only negative results.
This mutation is generally composed of five, or seven two-ounce cases.
The block of the ninth mutation is seven inches in diameter, and holds six spokes, six feet long each, with holes and grooves for leaders, as those in the dodecaedron.
The nave of the fifth mutation must be four and a half inches in diameter, and furnished with ten or twelve spokes, eighteen inches in length each.
This mutation must be fired by a leader, brought from the tail of one of the cases on the sixth mutation.
The blocks of these may be turned out of one piece, whose length from the barrel of the seventh mutation to the block of the ninth, must be twelve inches.
This mutation consists of eight spokes fixed in a block.
The nave of the seventh mutation must be five and a half inches in diameter, and furnished with eight spokes.
Vries has pointed out that regardless of the possible origin of new species by mutation the old species may persevere.
Every fact of consciousness as purely individual, relates only to the being that experiences it; neither the order of intelligences, nor that of truth suffers any mutation from my existence or non-existence.
We should be like an insensible body placed in the immensity of space, which would suffer no mutation were every thing around it to disappear, and would perceive no change even if it were itself to sink into the abyss of nothing.
This was the payment known as the lods et ventes, a mutation fine which the seigneur had the right to demand whenever a farm changed hands by sale or by descent, except to direct heirs.
When his seigneury changed owners by sale or by inheritance other than in direct descent, a mutation fine known as the quint was payable to the public treasury.
