▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
Genetic tests are located in China the first dogs
Investigadores suecos han encontrado nuevas pruebas de que el origen de la variedad de lobo ancestro de los perros domésticos se localiza en elSoutheast Asia. These results go against the theories that place the canine cradle in the Middle East.
El doctorPeter Savolainen, researcher in evolutionary genetics at the Royal Institute of Technology (KTH), concludes in a new study published this Wednesday that an Asian region south of the Yangtze River was the main place, and probably unique, where were wolves first domesticated by man.
Data on genetics, morphology and behavior clearly show that dogs are descended from wolves, but there has never been a scientific consensus on where in the world the domestication process began. «Nuestro análisis del cromosoma Y del ADN confirma que los lobos fueron domesticados por primera vez al sur del río Yangtze, in southern China or Southeast Asia, lo que denominaos región ASY», says Savolainen.
STRONG EVIDENCE
Chromosome data and support the prior evidence of mitochondrial DNA. «En conjunto, los dos estudios proporcionan una fuerte evidencia de que los perros se originaron en esta región», says Savolainen.
Los datos arqueológicos y un estudio genético publicado recientemente en la revista Nature sugerían que los perros se originaron en Oriente Medio. But Savolainen rejects that view. «Debido a que ninguno de estos estudios incluye muestras de la región ASY, la evidencia de ASY ha sido pasada por alto», says.
Peter Savolainen and Mattias Oskarsson doctoral student worked with Chinese colleagues to discuss the male DNA of dogs around the world. Su estudio ha sido publicado en la revista científica Heredity.
Approximately half of the genetic reserve is shared universally around the world, mientras que sólo la región ASY tenía toda la gama de diversidad genética. «Esto demuestra que las reservas genéticas de todas las demás regiones del mundo probablemente se originan en la región ASY», says Savolainen.
Source: europapress
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
Sociocognitivo of canine behavior resembles that of a small child
A new study says that dogs not only capture the words we say, but also our intention to communicate with them, as published by the researchers in 'Current Biology'. These findings could help explain why so many people treat their furry friends as if they were children., the receptivity of the dogs for communication is surprisingly similar to the responsiveness of young children, say scientists.
«El aumento de la evidencia apoya la idea de que seres humanos y perros comparten algunas habilidades sociales; the sociocognitivo of canine behavior, for example, It resembles a child of between 6 months and 2 years of age, en muchos aspectos», says József Topál, of the Hungarian Academy of Sciences, quien añade que «la utilización de señales ostensibles es una de estas características: dogs, as well as human babies, son sensibles a las señales que indican la intención comunicativa». These signals include oral care and eye contact, although it is not yet clear whether dogs use similar pathways in the brain for signal processing..
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
10 of the things you shouldn't do with your pet.
The relationship between a person and your pet can be absurd and sometimes petty. Even activities seemingly innocent as push a cat in a buggy or put bonds in the hair of a dog can be a cruel torture for the animal.
Here they are 10 of the things that owners likes to do with their pets.
Contenido Los Inconvenientes de Despertar a Nuestras Mascotas: Respetando su Sueño y Bienestar Despertar a nuestras queridas mascotas puede parecer ...
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
Put duct tape on his legs.
Pets bear a great deal of humiliation, but one of the most humiliating things that owners love to do is put the tape in their legs.
It seems funny to see cats and dogs twist and adhere to the ground with each step that give. This joke, seemingly innocent, It is frankly a torture for the animal.
Some pet owners have a habit of making fun of their dogs and cats with toys and goodies.
You can enjoy watching your dog looking for without rest a ball you never tiraste, but this kind of jokes can make it unstable and make him an aggressive and disobedient animal.
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
Intelligence of dogs
Performed by Stanley Coren
Classification of dogs according to their functional and obedience intelligence
Of 1 to 10: The 10 races with functional intelligence and highest obedience. Less than five exercises to understand orders new. Ability to remember without the need to repeatedly practice tests. They respond to the first order the 95 % of the times at least. They have a rapid response even at a distance. They learn to properly being trained by coaches relatively inexperienced.
Of 11 to 26: Excellent working dogs. Learning of simple orders between 5 and 15 repetitions of the exercise. Remember easily but do improve with practice. They respond to the first order on the 85 % of the times. For more complex orders need more time. Possibly at some distance from the owner takes a little to respond. Virtually all coaches can obtain good results.
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
Vision of the dog
Its rango de campo visuales más amplio que el de los humanos pero ve menos detalles, Therefore, towards what is the background of the vision image, the dog is "myopic" since it distinguishes very blurry details because they see in gradations of gray and certain ranges of colors but these gradations become indistinguishable at a certain distance..
This type of vision and the increased importance of the other senses in the dog because his predecessors were crepuscular hunters and in light conditions the sight was inefficient, therefore they had to be guided more by smell and hearing. From this it is concluded that the canine visual system is designed to be efficient under low light conditions in contrast to the human that was designed to work in broad daylight.
The canine visual system is perfectly capable of working adapting to a wide range of light conditions., its visual in conditions of low light ability helps him as a predator, since if he could not see very well in twilight conditions he would not be able to hunt his prey, the amount of light a dog needs to see is far less than a human needs.
The retinadel ojo canino está compuesta principalmente por fotorreceptores en forma de bastones, These photoreceptors work very well in low light conditions, They also have a limited amount of photoreceptors in cone-shaped working in good lighting conditions. These cones are responsible for in human color vision because the human eye contains large amount of cones and fewer sticks, exactly to the setback that in dogs therefore the vision of these is not in colors completely.
The visión nocturna o crepuscularde los canes es ayudada también por el uso del tapetum lucidum que asemeja a una pantalla reflectiva localizada por detrás de los fotorreceptores, This membrane is what makes shine the eyes of dogs when light reaches them in the dark, this membrane acts as a kind of light amplifier and makes the photoreceptors work as if there were a greater amount of light. This membrane is located in the upper half of the retina, the lower part is called tepetum nigrum and is composed of dark pigments not refractory, These two parts are the dog to have good vision in conditions of low light or with a very bright sky or light conditions which reflect very clearly (Sea, desert, etc).In Rod photoreceptors are responsible for the detection of movement and the shadows which is more difficult to do in cone photoreceptors.
The visión del perropor lo tanto está muy bien preparada para detectar movimientos a distancias superiores a los 850 m, But if the same object is still only can differentiate it into one smaller distance range (less than the 550 m).
The visual field of dogs varies to some degree depending on the breed due to the particular shape of the skull., position of the eyes and shape and position of the nose.
The campo visualpromedio de un perro se encuentra entre los 240 – 250 degrees, much larger than the human that is only 180 degrees. Is this difference in the visual field dogs detected movements to its around us still by his side can not perceive, This visual field is wider than sideways in the dog but turn the dog sees far less detail than the human.The depth of the visual field, as already said, It is directly related to the cranial structure, therefore it differs according to the race and the type of skull.
The profundidad promedio del campo visualen los perros va de los 30 to the 60 degrees, much smaller than the human that is in 140 degrees through its binocular vision.This shallow in the visual field of the dog makes you cannot very well measured distances far away and allows you to distinguish detail at certain distances, nor are they working in the accommodation of the visual and just focus can carry it out with placed objects between the 50 and 33 cm., In contrast to the children that can do you with placed objects to 7 cm., dogs compensate for this lack using his other senses such as smell and taste, as humans age dogs begin to have disorders in visual accommodation.
The vision or not in colors of dogs there are studies to the contrary and to favour, the most modern and scientifically controlled indicate that dogs have a type of color vision, but not in the same grades than humans.
The photoreceptor used in color vision is the cone and cone in the retinas of the dogs have been found. These cones are present but in much fewer numbers and represent slightly less than the 10% of the total of the photoreceptors of the dog.
Aparentemente hay dos tipos deconos en la retina canina: one of them see in shades of purple and the other type does see yellow greenish shades. Due to this, it could be said that the visual spectrum of dogs is divided into two tonalities., in the purple range- purplish blue (probably more bluish) and the other yellow-green yellow and Red (probably be seen as yellowish).
The greenish-blue tones are probably seen by dogs as grey shades. The dogs are unable to distinguish colors that we appear as green, yellow-green, Orange or red and are also unable to differentiate between the blue-green gray. But dogs are much better able to differentiate between the different shades of grey that people which is a great advantage to be able to see and discriminate objects with low light.
All preceding may indicate us that the visual system of the canines is worse than the human but this occurs only in some aspects, in others, such as seen in bright or low-light conditions (Sea, desert, snow) differentiation of gray and their depths, etc. the canine system is much more efficient than the human. These differences must be in a 90% to each visual system is made to measure for each species natural and primitive living conditions.
Source:»Vision in dogs», Paul E. Miller, DVM and Christopher J. Murphy, DVM.
▷ The world of Pets: Dogs, cats, birds, reptiles, amphibians
List of longest dogs
Los perros que figuran como «Verificado» son aquellos cuyas edades han sido publicadas enGuinness World Records or in other reliable sources. Los que figuran como «no verificadas» son aquellos cuya supuesta edad es de menos certeza.