|
|
|
|
This page last updated on Thu Sep 2, 2010
|


| # |
subject
|
title
|
description
|
|
| 1 |
01 - Variations Under Domestication
|
01-08 - Breeds of the Domestic Pigeons, their Differences and Origin
|
I have discussed the probable origin of domestic pigeons at some, yet quite insufficient, length; because when I first kept pigeons and watched the several kinds, well knowing how truly they breed, I felt fully as much difficulty in believing that since they had been domesticated they had all proceeded from a common parent, as any naturalist could in coming to a similar conclusion in regard to the many species of finches, or other groups of birds, in nature. One circumstance has struck me much; namely, that nearly all the breeders of the various domestic animals and the cultivators of plants, with whom I have conversed, or whose treatises I have read, are firmly convinced that the several breeds to which each has attended, are descended from so many aboriginally distinct
species.
Ask, as I have asked, a celebrated raiser of Hereford cattle, whether his cattle might not have descended from long-horns, or both from a common parent-stock, and he will laugh you to scorn. I have never met a pigeon, or poultry, or duck, or rabbit fancier, who was not fully convinced that each main breed was descended from a distinct species.
 | | Hereford Cow |
 | | Long Horn Cow |
Van Mons, in his treatise on pears and apples, shows how utterly he disbelieves that the several sorts, for instance a Ribston-pippin or Codlin-apple, could ever have proceeded from the seeds of the same tree.
 | | Pear |
 | | apple |
Innumerable other examples could be given.
The explanation, I think, is simple: from long-continued study they are strongly impressed with the differences between the several races; and though they well know that each race varies slightly, for they win their prizes by selecting such slight differences, yet they ignore all general arguments, and refuse to sum up in their minds slight differences accumulated during many successive generations.
May not those naturalists who, knowing far less of the laws of inheritance than does the breeder, and knowing no more than he does of the intermediate links in the long lines of descent, yet admit that many of our domestic races are descended from the same parents- may they not learn a lesson of caution, when they deride the idea of species in a state of nature being lineal descendants of other species?
|
Edit
|
New
|
Delete
|
| 2 |
01 - Variations Under Domestication
|
01-09 - Principles of Selection anciently followed, and their Effects
|
Let us now briefly consider the steps by which domestic races have been produced, either from one or from several allied species.
Some effect may be attributed to the direct and definite action of the external conditions of life, and some to habit; but he would be a bold man who would account by such agencies for the differences between a dray- and race-horse, a greyhound and bloodhound, a carrier and tumbler pigeon.
 | | Dray Horse |
 | | Race Horse |
 | | greyhound |
 | | bloodhound |
 | | Tumbler Pigeon |
One of the most remarkable features in our domesticated races is that we see in them adaptation, not indeed to the animal's or plant's own good, but to man's use or fancy.
Some variations useful to him have probably arisen suddenly, or by one step; many botanists, for instance, believe that the fuller's teasel, with its hooks, which cannot be rivalled by any mechanical contrivance, is only a variety of the wild Dipsacus; and this amount of change may have suddenly arisen in a seedling.
 | | Fuller's Teasel |
So it has probably been with the turnspit dog; and this is known to have been the case with the ancon sheep.
But when we compare the dray-horse and race-horse, the dromedary and camel, the various breeds of sheep fitted either for cultivated land or mountain pasture, with the wool of one breed good for one purpose, and that of another breed for another purpose; when we compare the many breeds of dogs, each good for man in different ways; when we compare the game-cock, so pertinacious in battle, with other breeds so little quarrelsome, with "everlasting layers" which never desire to sit, and with the bantam so small and elegant; when we compare the host of agricultural, culinary, orchard, and flower-garden races of plants, most useful to man at different seasons and for different purposes, or so beautiful in his eyes, we must, I think, look further than to mere variability.
 | | Ancon Sheep |
 | | Dray Horse |
 | | Race Horse |
 | | camel |
 | | sheep |
We cannot suppose that all the breeds were suddenly produced as perfect and as useful as we now see them; indeed, in many cases, we know that this has not been their history. The key is man's power of accumulative selection: nature gives successive variations; man adds them up in certain directions useful to him. In this sense he may be said to have made for himself useful breeds.
|
Edit
|
New
|
Delete
|
| 3 |
01 - Variations Under Domestication
|
01-09 - Principles of Selection anciently followed, and their Effects
|
The great power of this principle of selection is not hypothetical.
It is certain that several of our eminent breeders have, even within a single lifetime, modified to a large extent their breeds of cattle and sheep.
 | | cattle |
 | | sheep |
In order fully to realise what they have done, it is almost necessary to read several of the many treatises devoted to this subject, and to inspect the animals.
Breeders habitually speak of an animal's organisation as something plastic, which they can model as they please.
If I had space I could quote numerous passages to this effect from highly competent authorities.
Youatt, who was probably better acquainted with the works of agriculturists than almost any other individual, and who was himself a very good judge of animals, speaks of the principle of selection as "that which enables the agriculturist, not only to modify the character of his flock, but to change it altogether. It is the magician's wand, by means of which he may summon into life whatever form and mould he pleases."
Lord Somerville, speaking of what breeders have done for sheep, says:- "It would seem as if they had chalked out upon a wall a form perfect in itself, and then had given it existence."
In Saxony the importance of the principle of selection in regard to merino sheep is so fully recognised, that men follow it as a trade: the sheep are placed on a table and are studied, like a picture by a connoisseur; this is done three times at intervals of months, and the sheep are each time marked and classed, so that the very best may ultimately be selected for breeding.
 | | sheep |
 | | clay |
 | | Merino sheep |
|
Edit
|
New
|
Delete
|
| 4 |
01 - Variations Under Domestication
|
01-09 - Principles of Selection anciently followed, and their Effects
|
What English breeders have actually effected is proved by the enormous prices given for animals with a good pedigree; and these have been exported to almost every quarter of the world.
The improvement is by no generally due to crossing different breeds; all the best breeders are strongly opposed to this practice, except sometimes amongst closely allied sub-breeds.
And when a cross has been made, the closest selection is far more indispensable even than in ordinary cases.
If selection consisted merely in separating some very distinct variety, and breeding from it, the principle would be so obvious as hardly to be worth notice; but its importance consists in the great effect produced by the accumulation in one direction, during successive generations, of differences absolutely inappreciable by an uneducated eye- differences which I for one have vainly attempted to appreciate.
Not one man in a thousand has accuracy of eye and judgment sufficient to become an eminent breeder. If, gifted with these qualities, he studies his subject for years, and devotes his lifetime to it with indomitable perseverance, he will succeed, and may make great improvements; if he wants any of these qualities, he will assuredly fail.
Few would readily believe in the natural capacity and years of practice requisite to become even a skilful pigeon fancier.
 | | pigeon |
|
Edit
|
New
|
Delete
|
Page 1 of 110 (4 rows per page)
Statistics and Drill Down Data Mining
|
|
|
title
|
#
|
|
01-08 - Breeds of the Domestic Pigeons, their Differences and Origin
|
1
|
1
|
|
01-09 - Principles of Selection anciently followed, and their Effects
|
6
|
7
|
|
01-10 - Methodical and Unconscious Selection
|
5
|
12
|
|
01-11 - Unknown Origin of our Domestic Productions
|
5
|
17
|
|
01-12 - Circumstances favourable to Man's Power of Selection
|
3
|
20
|
|
01-13 - Summary
|
2
|
22
|
|
02-01 - Variability
|
2
|
24
|
|
02-02 - Individual Differences
|
2
|
26
|
|
02-03 - Doubtful Species
|
10
|
36
|
|
02-04 - Wide-ranging, much diffused, and common Species vary most
|
3
|
39
|
|
02-05 - Species of the Larger Genera in each Country vary more frequently than the Species of the Smaller Genera
|
2
|
41
|
|
02-06 - Many of the Species included within the Larger Genera resemble Varieties in being very closely, but unequally, related to each other, and in having restricted ranges
|
2
|
43
|
|
02-07 - Summary
|
2
|
45
|
|
03-01 - Bears on Natural Selection
|
2
|
47
|
|
03-02 - The Term, Struggle for Existence, used in a large sense
|
2
|
49
|
|
03-03 - Geometrical Ratio of Increase
|
2
|
51
|
|
03-04 - Rapid Increase of naturalised Animals and Plants
|
3
|
54
|
|
03-05 - Nature of the Checks to Increase
|
2
|
56
|
|
03-06 - Competition Universal
|
2
|
58
|
|
03-07 - Effects of Climate
|
2
|
60
|
|
03-08 - Protection from the Number of Individuals
|
2
|
62
|
|
03-09 - Complex Relations of all Animals and Plants Throughout Nature
|
5
|
67
|
|
03-10 - Struggle for Life most severe between Individuals and Varieties of the same Species
|
2
|
69
|
|
03-11 - The Relation of Organism to Organism the Most Important of All Relations
|
4
|
73
|
|
03-12 - Summary
|
2
|
75
|
|
04-01 - Natural Selection
|
5
|
80
|
|
04-02 - Its Power Compared with Man's Selection
|
2
|
82
|
|
04-03 - Its Power on Characters of Trifling Importance
|
2
|
84
|
|
04-04 - Its Power at All Ages and on Both Sexes
|
2
|
86
|
|
04-05 - Sexual Selection
|
2
|
88
|
|
04-06 - On the generality of Intercross Between Individuals of the Same Species
|
9
|
97
|
|
04-07 - Illustrations of the Action of Natural Selection:
|
10
|
107
|
|
04-08 - On the Intercrossing of Individuals
|
8
|
115
|
|
04-09 - Circumstances favourable for the production of new forms through Natural Selection
|
12
|
127
|
|
04-10 - Extinction caused by Natural Selection
|
3
|
130
|
|
04-11 - Divergence of Character
|
26
|
156
|
|
04-12 - On the Degree to which Organisation tends to advance
|
11
|
167
|
|
04-13 - Convergence of Character
|
8
|
175
|
|
04-14 - Summary of Chapter
|
4
|
179
|
|
05-01 - Effects of External Conditions
|
2
|
181
|
|
05-02 - Use and Disuse of Parts, combined with Natural Selection, Organs of Flight and Vision
|
7
|
188
|
|
05-03 - Acclimatisation
|
4
|
192
|
|
05-04 - Correlation of Growth
|
5
|
197
|
|
05-05 - Compensation and Economy of Growth
|
2
|
199
|
|
05-06 - False Correlation
|
1
|
200
|
|
05-07 - Multiple, Rudimentary, and Lowly-organised Structures are Variable
|
2
|
202
|
|
05-08 - Parts Developed in an Unusual Manner are Highly Variable
|
5
|
207
|
|
05-09 - Specific Characters more Variable than Generic Characters
|
2
|
209
|
|
05-10 - Secondary Sexual Characters Variable
|
3
|
212
|
|
05-11 - Species of the Same Genus Vary in an Analogous Manner
|
2
|
214
|
|
05-12 - Reversion to Long Lost Characters
|
10
|
224
|
|
05-13 - Summary
|
2
|
226
|
|
06-01 - Difficulties on the Theory of Descent with Modification
|
5
|
231
|
|
06-02 - Transitions
|
2
|
233
|
|
06-03 - Absence or Rarity of Transitional Varieties
|
10
|
243
|
|
06-04 - Transitions in Habits of Life
|
7
|
250
|
|
06-05 - Diversified Habits in the Same Species
|
2
|
252
|
|
06-06 - Species with Habits Widely Diffferent from those of their Allies
|
3
|
255
|
|
06-07 - Organs of extreme Perfection
|
5
|
260
|
|
06-08 - Means of Transition
|
6
|
266
|
|
06-09 - Cases of Difficulty
|
5
|
271
|
|
06-10 - Natura Non Facit Saltum
|
2
|
273
|
|
06-11 - Organs of Small Importance
|
6
|
279
|
|
06-12 - Organs not in all Cases Absolutely Perfect
|
13
|
292
|
|
06-13 - Summary: The Law of Unity of Type and of the Conditions of Existence Embraced by the Theory of Natural Selection
|
8
|
300
|
|
07-01 - Instincts comparable with habits, but different in their origin
|
2
|
302
|
|
07-02 - Instincts Graduated
|
2
|
304
|
|
07-03 - Aphides and ants
|
1
|
305
|
|
07-04 - Instincts variable
|
1
|
306
|
|
07-05 - Domestic instincts, their origin
|
1
|
307
|
|
07-06 - Natural instincts of the cuckoo, ostrich, and parasitic bees
|
1
|
308
|
|
07-07 - Slave-making ants
|
1
|
309
|
|
07-08 - Hive-bee, its cell-making instinct
|
1
|
310
|
|
07-09 - Difficulties on the theory of the Natural Selection of instincts
|
1
|
311
|
|
07-10 - Neuter or sterile insects
|
1
|
312
|
|
07-11 - Summary
|
1
|
313
|
|
08-01 - Distinction between the sterility of first crosses and of hybrids
|
1
|
314
|
|
08-03 - Laws governing the sterility of hybrids
|
1
|
315
|
|
08-04 - Sterility not a special endowment, but incidental on other differences
|
1
|
316
|
|
08-05 - Causes of the sterility of first crosses and of hybrids
|
1
|
317
|
|
08-06 - Parallelism between the effects of changed conditions of life and crossing
|
1
|
318
|
|
08-07 - Fertility of varieties when crossed and of their mongrel offspring not universal
|
1
|
319
|
|
08-08 - Hybrids and mongrels compared independently of their fertility
|
1
|
320
|
|
08-09 - Summary
|
1
|
321
|
|
09-01 -On the absence of intermediate varieties at the present day
|
1
|
322
|
|
09-02 - On the nature of extinct intermediate varieties; on their number
|
1
|
323
|
|
09-03 - On the vast lapse of time, as inferred from the rate of deposition and of denudation
|
1
|
324
|
|
09-04 - On the poorness of our palaeontological collections
|
1
|
325
|
|
09-05 - On the intermittence of geological formations
|
1
|
326
|
|
09-06 - On the absence of intermediate varieties in any one formation
|
1
|
327
|
|
09-07 - On their sudden appearance in the lowest known fossiliferous strata
|
1
|
328
|
|
10-01 - On the slow and successive appearance of new species
|
1
|
329
|
|
10-02 - On their different rates of change
|
1
|
330
|
|
10-03 - Species once lost do not reappear
|
1
|
331
|
|
10-04 - Groups of species follow the same general rules in their appearance and disappearance as do single species
|
1
|
332
|
|
10-05 - On Extinction
|
1
|
333
|
|
10-06 - On simultaneous changes in the forms of life throughout the world
|
1
|
334
|
|
10-07 - On the affinities of extinct species to each other and to living species
|
1
|
335
|
|
10-08 - On the state of development of ancient forms
|
1
|
336
|
|
10-09 - On the succession of the same types within the same areas
|
1
|
337
|
|
10-10 - Summary of preceding and present chapters
|
1
|
338
|
|
11-01 - Present distribution cannot be accounted for by differences in physical conditions
|
1
|
339
|
|
11-02 - Importance of barriers
|
1
|
340
|
|
11-03 - Affinity of the productions of the same continent
|
1
|
341
|
|
11-04 - Centres of creation
|
1
|
342
|
|
11-05 - Means of dispersal, by changes of climate and of the level of the land, and by occasional means
|
1
|
343
|
|
11-06 - Dispersal during the Glacial period co-extensive with the world
|
1
|
344
|
|
12-10 - Distribution of fresh-water productions
|
1
|
345
|
|
12-20 - On the inhabitants of oceanic islands
|
1
|
346
|
|
12-30 - Absence of Batrachians and of terrestrial Mammals
|
4
|
350
|
|
12-40 - On the relations of the inhabitants of islands to those of the nearest mainland
|
2
|
352
|
|
12-50 - On colonisation from the nearest source with subsequent modification
|
11
|
363
|
|
12-60 - Summary of the last and present chapters
|
4
|
367
|
|
13-01 - CLASSIFICATION, groups subordinate to groups
|
1
|
368
|
|
13-02 - Natural system
|
1
|
369
|
|
13-03 - Rules and difficulties in classification, explained on the theory of descent with modification
|
13
|
382
|
|
13-04 - Classification of varieties
|
1
|
383
|
|
13-05 - Descent always used in classification
|
6
|
389
|
|
13-06 - Analogical or adaptive characters
|
2
|
391
|
|
13-07 - Affinities, general, complex and radiating
|
2
|
393
|
|
13-08 - Extinction separates and defines groups
|
4
|
397
|
|
13-09 - MORPHOLOGY, between members of the same class, between parts of the same individual
|
1
|
398
|
|
13-10 - EMBRYOLOGY, laws of, explained by variations not supervening at an early age, and being inherited at a corresponding age
|
1
|
399
|
|
13-11 - RUDIMENTARY ORGANS; their origin explained
|
1
|
400
|
|
13-12 - Summary
|
1
|
401
|
|
14-01 - Recapitulation of the difficulties on the theory of Natural Selection
|
7
|
408
|
|
14-02 - Recapitulation of the general and special circumstances in its favour
|
10
|
418
|
|
14-03 - Causes of the general belief in the immutability of species
|
13
|
431
|
|
14-04 - How far the theory of natural selection may be extended
|
1
|
432
|
|
14-05 - Effects of its adoption on the study of Natural history
|
5
|
437
|
|
14-06 - Concluding remarks
|
2
|
439
|
|
wolfs
|
1
|
440
|
|
|
|
|