Race

Races of breeding

The term “race” is mainly used for the domesticated Espèce S (see section Race and biology low). It refers to individualized populations of same a Espèce being morphological and physiological hereditary good distinct from the other populations, i.e. having a individualized average Génotype and that the man endeavoured to maintain sometimes for a very long time, but that it can make evolve/move in the time according to economic imperatives or of modes.

The terms “race pure” or “fixed race” often do not correspond to an objective reality being given the history of the races, and the selection whose they are the object. The Cheval known as English Pur-sang for example is resulting from the crossing of mares Britannique S and standards barbs, originating in the the Maghreb, thus probably that of Arab Pur-sang S. These terms can be however taken with a relative meaning, and there exist homogeneous and old races.

It is now possible to obtain perfectly homogeneous populations by cloning, and of the pure lines for a gene even the totality of the Génome by techniques of reproduction (animal Homozygote S: both Chromosome S of each pair will be then identical, and the Gène S transmitted to the invariable Progéniture). The pure lines have a primarily scientific interest, though the principle of line as subdivision of a race is followed in breeding, and can intervene when diagrams of reproduction are prepared.

A race of breeding is given in several ways:

It can describe the population of a domestic species of an area, which presents a certain homogeneity;
It can be primarily defined by a standard, i.e. a whole of criteria which define the ideal individual. These criteria are often limited to the morphology, the size and the color for the pet ornament and . One adds to it in certain cases of the particular aptitudes, like the behavior vis-a-vis a herd for certain races of Sheepdog;
There is generally the condition of origin, the parents of an animal having to be of this race. This condition is not required in breeding for the hens of ornament. When this condition is applied, the race is isolated genetically, though this insulation can be recent and that one envisages sometimes the possibility of exceptional or regular exemptions;
When it is about a race of production, these criteria are combined in general with that of the performances, which is in general paramount.

In the preceding cases, the concept of race describes a whole of objectively homogeneous animals of appearance and origin, though it there was added objectives of improvement of this homogeneity in a case, and of improvement of the performances or various characters in the other.

It should be noted that one almost defines also certain races apart from criteria of homogeneity and common origin, according to a will of organization of the breeding of a species. It is the case of certain races of Vache S which were " créées" by fusion of several local races, or of the horse known as French Saddle and French Pony of saddle, for which one authorizes origins and crossings limited but heterogeneous. These races are thus formed with objectives of use, production, and to join together and identify a type of animal. They can be invited to be " thereafter; fermées" with the new contributions or on the contrary to be permanently supplied with products of first generation of crossings of other races, as it is the case of the Poney S of saddle resulting from races of ponies and Arab Pur-sang.

Examples of races:

of Cat S: Blue European Russian, , Persan;
of Dog S: Labrador, Greyhound, burrow, Mastiff;
of horses: Percheron, Arab Thorough-bred;
of Bovine S: Charolaise, Norman, Montbéliarde;
of Ovine S: merino, lacaune, texel;
of Porcine S: Piétrain (pig), Broad white;
of hens: Crèvecoeur, Houdan, Field bean, Marans.

The criteria of definition of a race thus correspond in general to a goal , and aims in view. Thus, one can consider that the variety of the races equine, cat-like or canine answers a preoccupation with a mercatic segmentation, i.e. it would make it possible purchasers of different profiles to buy a Saint-Bernard, a Caniche or a chihuahua.

From where the sentence “if the species proceeds of Nature, the race proceeds of the culture” (Raymond Triquet) and thus the proposal for definition of animal and or vegetable race:

“ a social Construction correspondent with an artificial subdivision of the species carried by a group of human having a common objective. This makes it possible to convey, of the genetics, of the culture, but also has an significant impact in the medical approach. ”

Race and genetics

The drafting of the " laws of the hérédité" based on work of Mendel allows to connect a race given to a particular genotype.

For including/understanding this bond well, it is advisable to distinguish two concepts well:

observable characters (the Phenotype of the individual);
the information carried by the Genome (the Genotype of the individual).

It is the interaction of the genotype and the Environnement which determines the phenotype.

In certain simple cases, the genes are expressed in a visible way, such as for example the peas studied by Mendel, which can be smooth or wrinkled, or the Drosophile S (flies studied by Morgan, Nobel Prize in 1933), of which the eyes can be red or white, according to a specific gene. In these two cases, one can thus clearly define races (the term of variety is of more frequent use in the case of the plants):

smooth varieties of pea and varieties of wrinkled peas;
varieties of green peas and yellow varieties of pea;
race of drosophilas in red eyes and race of drosophilas in white eyes.

According to the studied character, an individual can belong to several races. Thus, a wrinkled yellow pea belongs it to the variety of yellow peas and that of wrinkled peas.

In addition, all the characters are not visible, some are of a biochemical nature (like the capacity to feel a given molecule, the Blood group, etc), and in addition an individual of a species (vegetable or animal) presents a big number of genes, therefore as much of possibility of defining races.

For the animal species used in breeding, or the plant species cultivated at ends Alimentaire S, Industrielle S or decorative, the pressure of selection exerted by the man led to a homogeneity stronger (compared to genes controlling the required phenotypes) population, and correlatively to an impoverishment of genetic diversity, which weakens this population with respect to the aggressions of any nature, as the Maladie S. Of the commercial requirements result in defining many standards of races or varieties corresponding to varied needs; thus, the animals or plants which do not correspond to the standard of a race (or variety) do not take part in the reproduction.

The Microorganisme S used in the Industrie were also the object, for a long time, of similar selections (for example, the Brewers' yeast).

Recently, the genetic Engineering makes it possible to modify genes of a species in order to create “genetically modified” species or Transgénique S , whose new properties meet the needs for those which exploit them.

Race and biology

In the classification of the living beings, the species (i.e. a whole of individuals generally interféconds) is the last subdivision (or Taxon) unanimously allowed. Beyond, one speaks about Sous-espèce for the animals and vegetable wild, about race for the pets and variety for the plants, terms which are based on criteria of geographical distribution (subspecies of the wolf, local races of pets), of morphological resemblance, ecological specialization (wild animals), or uses for the domestic animals (beef breeds or races dairy). Except domestic species, the current biologists thus use very little the term of race for the subdivisions of level lower than the species.

The concept of race thus seems mainly used for the pets, for which it is during concept of subspecies in the wild animals. At the species existing in a wild and domestic state (wolf/Dog, Wild boar/Pig, Cock gilded/domestic hen), the pet is sometimes regarded as a distinct species, the tendency being however to classify it like a subspecies of the wild species: the dog passing of canis familiaris to Canis lupus familiaris. According to this classification, the whole of the races of dogs of all sizes and whole world are put at the same level as a geographical subspecies like the Arctic Wolf: Canis lupus arctos . In the same way for the pig, the poule.
Contrary, certain races of pets can result from several subspecies, like the Zébu African resulting from the zebu of India and the Bœuf, even of several species like certain races of Porc resulting from Sus scrofa and Sus celebensis.

At the vegetable one employs the terms of cultivated varieties or cultivars.

“If one wishes to have greater number of rows of let us tax, their name is formed by the addition of the prefix “under” (“sub-”) to the names of the principal or secondary rows. A plant can be thus seen classifying in tax with the following rows (by decreasing order): regnum, subregnum, divisio or phylum, subdivisio or subphylum, classis, subclassis, ordo, subordo, familia, subfamilia, tribes, subtribus, genus, subgenus, sectio, subsectio, series, subseries, species, subspecies, varietas, subvarietas, formed, subforma. ”

This extract of the international Code of botanical nomenclature watch well the complexity and the progressiveness of categorizations necessary in Biology. If the majority of the specialists agree to the level them species, knowledge if a population showing of the special characters must be a subspecies, a variety or a form, often makes debate. The individuals of a subspecies remaining always interféconds, one often observes inside a species of the populations in the course of insulation, sometimes presenting morphological differences, sometimes ecological differences (ecotype S) without necessary correlation with their state in genetic differentiation.

These subdivisions are thus rather hazardous and complex; it is not rare to see them called into question according to the importance more or less great data to a discriminating character. Moreover, the interfecondity allowing the reproduction crossed between two subspecies, the choice to classify an individual in such or such group can be completely arbitrary. They can thus be defined without ambiguity only in the event of perfect insulation of the two subspecies; geographically, for example. That explains the reserves of the biologists vis-a-vis the definition of human races.

Threatened races and species

Since a few years, and in particular since the Convention on biological diversity of Rio, FAO, the GOOSE UNO, of the ONG S and certain international scientific authorities (IUBS, UICN.) worry about the accelerated disappearance of domesticated species.
As example, only in France: in 100 years, the number of races of cattle passed several hundreds to a dozen in the years 2000. And when a " race animale" remain, there remains only some individuals about it, i.e. the diversity of its genetic inheritance was impoverished considerably, which harms the capacities of ecological Résilience of the agro-systems and risk to make difficult the adaptation of the breeding to the Climate changes and the diseases.

The evaluation of the ecosystems for the millenium showed that in spite of the Convention of Rio on the biodiversity and of the Protocole of Carthagène (on the Biosécurité), the number of the domestic races still crumbled, except in Europe and North America, but the decline was earlier there. UNO aims at the long-term conservation the biodiversity, for a " Division right and equitable of its advantages ". But we became tributary of less than 100 plants for 90% of our needs. Humanity until the beginning of the 20th century was nourished several thousands of plant species. It does not cultivate any today than approximately 150, of which three (Corn, corn, rice) provide nearly 60% to the calories and plant proteins. In same time, a standardization and a stabilization of the races and varieties were imposed by the large seed-bearer ones and the agro-alimentary sector via the installation of obligatory inscriptions on catalogs. This still accentuated the genetic loss of diversity of the agricultural resources, via the adaptation of a number increasingly lower of species, races and varieties with the homogenizing standards of the sector Agro-alimentaire. The domestic bees regress, just like the wild bees, for reasons still badly included/understood, but among which the genetic Pollution could have a responsibility. Zoonose S today mondialized like the prion known as " Mad cow " , the Disease of Newcastle, the Foot-and-mouth disease, or the virus H5N1 of the Avian flu resulted in killing on suspicion out of the million traditional livestock. Fault of having organized the conservation of the genetic inheritance of the old and local races, the animals shot down for the majority were replaced by animals of " races" industrial producing bought with naisseurs in the form of calves or of " Chicks one day old " by the stockbreeders (even bio), once again with the profit of a genetic homogenization related on the selection and the low number of reproducers.

In same time, the share of the territory available for wild nature regresses with the profit in particular of the intensive agriculture (42% on average of the surface of the EU, but 75% in areas such as the Nord/Pas-de-Calais Area or Picardy). The Sylviculture as intensifies, it are thus not in these spaces, in addition more and more fragmented as the genetic diversity of species relationships can be preserved, whereas the agricultural grounds are degraded everywhere in the world.

FAO inquired in 170 countries into becoming it during the 10 last years out of 6.379 races of livestock of mammals and domestic birds. The study shows with TWO LOST DOMESTIC RACES EACH WEEK, and 1.350 RACES MENACEES Of EXTINCTION. More than 1000 races were lost in 100 years. A third of the races of breeding is threatened of extinction.

The data of size of the populations are available only for 4.183 races, almost all in constant or accelerated regression. 740 races are already extinct. 1.335 (that is to say 32%) are in extreme cases of the extinction. The regression tends to accelerate, with a proportion of races of domestic mammals threatened of extinction: from 23 to 35% of 1995 to 2000 (in 15 years). Races of birds threatened of extinction passed from 51% of the total in 1995, to 63% in 1999. " If nothing is done, 2.255 races will be lost from here 2020. Even very productive and rustic varieties regressed. CRRG and the Conservatoire Botanique national of Bailleul (CNBB) saved in extremis carrot of Tilque (one of largest carrots of the old varieties), the sheep of Bolted, the Flemish cow, of the hundreds of varieties of fruits, a hundred old vegetables, but the Flemish pig definitively disappeared. These varieties are often represented only by one very small population, even a single tree.

Another problem is that of the genetic Pollution induced by the crossings of domesticated species (animal, vegetable.) with their wild parents or ancestors, crossings which can disturb the genetic base of wild species, even ecosystem, particularly with the GMO which can potentially become of super bad-grass , insecticides and tolerant with weeding total, being likely to become invasive, whereas the domestic species had generally a less aptitude to live without the assistance of the Man. An often quoted example is that of the gene passage of domestic pig in the wild boars, which in the absence of predatory natural and in a context of agrainage for hunting or food availability in the fields allows a greater prolificity.

Other uses of the term

In an aged direction, the term of race indicates the whole of the individuals belonging to the various generations of a family, of a dynasty. Examples: the race of Abraham, the race of the Capétiens, etc

With the Direction illustrated, the race indicates groups of people having common interests and behaviors.

The term also indicated at the 17th century the generations:

“ At this new race

Where I will have some credit

You will not pass for beautiful

That as much as I will have said it. ”

(Crow, Stanzas with Marchioness )

The term of race is often employed in the works of Medieval-fantastic Science-fiction and . The definition of race is then not the same one as in biology. In this context, it indicates groups of intelligent beings which are physical and often psychological different. The reproduction between different races is often unfertile.

See too

Idea of animal race and its evolution in the medium of the breeding Patricia Pellegrini

Genetic Biodiversity
Mongrel
Natural selection
human Race

Random links: