Here are 9 cold knowledge related to dogs. Look at how many you know~
1
Dogs are the first animal domesticated by humans. In taxonomics, the status of dogs has been controversial several times. Nowadays, people tend to agree that domestic dogs are not separate species, but a subspecies of wolf. So, dogs belong to wolves. But further up, wolves belong to the canine family. The dog wins back.
Dogs are the first species domesticated by humans, the first undisputed dog bone was found in a tomb 14,700 years ago. Humans may have domesticated dogs more than once. There may have been an independent domestication on the west and east sides of Eurasia. But about six thousand years ago, the dogs in the east seemed to have replaced the dogs in the west.
2
The real wild dogs also exist. The wolf whose dogs are domesticated are domesticated and wild. About four or five thousand years ago, humans came to Australia and brought the dog, but accidentally, yelled, the dog ran away and became wild! So, the current Australian wild dogs are found, which are considered to be another wild subspecies of wolf.
In addition to wolves, there are two animals with the word "wild dog" in the names of Asian wild dogs (that is, jackals) and African wild dogs. But they have a far-reaching relationship with dogs.
3
No collarbone, so dogs cannot be careless, so that they can get larger strides when running and jumping, which is more conducive to exercise.
such structure also brings a major disadvantage: the developed clavicle can attach more muscles, making the forelimbs more flexible. The clavicle of our human flexible forelimbs is indispensable. Even cats can slap people with their forelimbs. But the dog has nothing, he can only talk about everything.
4
The two stupid dogs are stuck! I just saw a dog mate, after the usual climb, a particularly embarrassing scene often appears: the male dog crawled off the female dog, but... their lower body is stuck and cannot be pulled away.
Yes, it's really stuck. This is a condition called a mating truncated condition. After the sperm is discharged, the genitals of the two dogs often get stuck together and stay for dozens of minutes. Such behavior seems to increase the probability of fertilization, but it can be fertilized without it! What to do if you encounter a predator when you get stuck together!
is a somewhat unreasonable behavior.
5
Observant dogs have hanged ears, curly tails and patterns
Many dogs have spots and patterns on their bodies, white or yellow star spots on their foreheads, soft ears and curly tails. This feature is actually related to their tame personality.
Scientists studied mammals before and after domestication and found that patterns, star spots, ear-collapsed, and curled tails appeared more frequently in domesticated animals. Russian scientists have even reproduced the emergence of these characteristics by targeting the domestication of silver foxes. These characteristics may be a more common marker in mammals and are even associated with domesticated genes.
6
The playful and cute dog has not grown up, and it was a wolf when he was a child. He had big eyes and short sniffles, and he looked much cute than the grown wolf. The dogs selected by the people have many breeds with short kisses and big eyes. Even the St. Bernard, who is oversized and has a wine barrel under his neck, has a short kiss.
Such a condition is called "school continuation", which means that the characteristics of childhood are retained after adulthood.
The continuation of dogs' young states not only appears in appearance, but also in character. Their curious, relatives, and playful personalities belong to their childhood.
Blowing bubbles is really fun!
7
The largest canine animal is... Among the existing wild canine animal, the largest species is a wolf. The largest of wolves are the two subspecies of Yukon Wolf and Magengliu Wolf. They both live in northern North America. The former is longer and the latter is thick and weighs up to 60 kilograms.
But in geography, there are still some larger canines. The most famous one is naturally the dire wolf, but it is just a little longer than the Yukon wolf and a little thicker than the horse. Its largest specimen is supposed to weigh up to 110 kg. But it is not the largest canine animal ever.
About ten million years ago, a kind of ancient canine named dog appeared in North America. They are the largest dogs in human history, and the largest specimen may weigh up to 170 kg when alive.
Who is not a baby yet...
8
The smallest canine animal
The smallest canine animal is (guō) fox.
In case you can't see this word...
This little fox living in arid areas in Africa has a maximum length of 40 cm and weighs only 1.6 kg. It can be said to be very mini! In order to adapt to the dark night, the fox has a pair of big ears, which can be said to be the cutest part of the whole body! The word "" in
fox is often written incorrectly. This name was found in the Republic of China, but in the subsequent simplification of Chinese characters, it became an uncommon character that was not included, which led to the trouble of printing. But their names are foxes. If you can't type the word "名名" is just right, but don't write it as fence foxes, let alone big-eared foxes, that's another animal!
cute, you can't raise
9
Silly dogs are good at running
Dogs inherit the stunts that wolf ancestors are good at running. Among mammals, there are many animals that are good at running. But there are few animals that are good at running long distances. A wolf is one of the animals that can run for a long time. They can walk for several hours at a slow speed of about 10 kilometers per hour, or chase for 20 minutes at a high speed of 50-60 kilometers per hour. Compared with the cheetah, the endurance is really amazing.
Under the selection and breeding of humans, many dog breeds are particularly good at running. For example, greyhound (tí), puppy. The greyhound can run at a high speed of up to 70 kilometers per hour, which can be said to be out of the ordinary.