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The Darwinian Theory of the Transmutation of Species
Robert MacKenzie Beverley
Sin vista previa disponible - 2016
according action admit advance advantage ages animals appear arrangement beauty become beginning believe birds blood body bones called cause certain character common condition connected considered continually course created creation creatures Darwin difficulty direction distinct earth effected evidence existence expressed fact female fishes foot formation geology give habits hand heart horse human imagination improvement instance instinct known learned less light living matter means millions modification Natural Selection never object observed organic origin passage perfect period plants position present principle produced Professor progenitor proof proved question race reason remarks result rocks says School seems seen separate Silurian soil species structure struggle succession suppose tail term Theory things thousand tion transformation Transmutation true turn varieties vertebrated whole
Página 7 - And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
Página 52 - Under changed conditions of life, it is at least possible that slight modifications of instinct might be profitable to a species; and if it can be shown that instincts do vary ever so little, then I can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. It is thus, as I believe, that all the most complex and wonderful instincts have originated.
Página 7 - And God said, Let the earth bring forth grass, the herb yielding seed and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so. And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
Página 27 - So again it is difficult to avoid personifying the word Nature ; but I mean by Nature, only the aggregate action and product of many natural laws, and by laws the sequence of events as ascertained by us.
Página xiii - In short, we shall have to treat species in the same manner as those naturalists treat genera, who admit that genera are merely artificial combinations made for convenience. This may not be a cheering prospect ; but we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species.
Página 113 - I can see no difficulty in a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.
Página 43 - The similar framework of bones in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse, — the same number of vertebrae forming the neck of the giraffe and of the elephant, — and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications.
Página xi - These facts, as will be seen in the latter chapters of this volume, seemed to throw some light on the origin of species — that mystery of mysteries, as it has been called by one of our greatest philosophers.
Página 221 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator 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.
Página 26 - Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change, to the beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection.