43 million years ago, in the far deep sea, there lived a fish with four legs, webbed feet and hooves, which scientists named "Peregocetus pacificus," meaning "a traveling whale that swam across the Pacific Ocean." They are not unknown prehistoric monsters, they are just explorers of the world, they have traveled in the Atlantic Ocean, run on the grasslands of South America, explored in the Pacific Ocean, and their corpses are scattered all over the world. Each fossil records their desire for the world, and they were the first explorers in nature, blowing away the thick fog that hung over the earth.
<h1 class="pgc-h-center-line" > trace back to the roots and look back at the vicissitudes of the sea</h1>
According to paleontologists, whale ancestors once lived on land and, like other land mammals, had 4 legs, which is what we know as ancient whales. There are many kinds of ancient whales, from the current research, the earliest whale is the Pakistani ancient whale, also known as the Bucky whale, which has a history of 50 million years, by the American paleontologist Philips. King Grych was discovered in Pakistan in 1979, hence the name.
They mainly live on land on the shores of lakes and prey on fish, and the earliest ancient Pakistani whales resemble wolves, with a long conical head, four feet on the ground, a slender tail, and hairy body. Bucky whales are the first steps of the cetacean family to the world, and when they disappeared from the world, the cetacean family ushered in a group of different descendants and began a new evolutionary epic.
In the long history of the bucky whale, the Bucky whale gradually evolved, the appearance of chocobo whales, followed by the birth of the Dharan whale, and then the Rhodes whale followed, and then after continuous development, they slowly began to get used to living in the water, their front legs gradually degenerated into flippers, the hind legs and hips disappeared, and finally became the whales we see today. The evolutionary history of ancient creatures is mysterious, and our study of whales is nothing less than Taicang barberry relative to the history of whales, which is insignificant, but the surprise of science is that it insists that the mystery of ancient cetaceans will be the eternal pursuit of scholars.
<h1 class= "pgc-h-center-line" > even though it is different from the past, it can still bloom dazzlingly</h1>
After the clouds parted, the water flowed for ten years
Today's whales have lost the legs that once conquered the mainland, but they still retain traces of the pelvis, and the phenomenon of return to the ancestors often occurs, and it is common for newborn whales to have hind limbs. Because whales are now often called whales, many people have forgotten that whales are mammals. Today's whales, even if they do not walk on the road like ancient times, still maintain the characteristics of mammals, with lung breathing and fetal birth, etc., and have some special physiological structures evolved to adapt to the aquatic environment.
Today's cetaceans are completely aquatic mammals, body shaped like fish, body length of more than 1 to 30 meters, the large whale, the small dolphin, bare skin, only the snout has a few hairs, no sweat glands and sebaceous glands. The forelimbs are fin-shaped, the hindlimbs are completely degenerated, only a pair of small bone pieces remain in the body, and the skin at the end of the tail expands left and right to form a horizontal tail fin. Without pinna, there is a thick layer of fat under the skin, which insulates and reduces the specific gravity of the body, which is conducive to swimming. Some species have dorsal fins. The eyes are small, no transient membranes, no tear glands, and poor vision. There are 1 to 2 external nostrils, located on the top of the head, commonly known as the air vents. Although there is no pinna, it is sensitive to hearing. There is 1 lobe on each side of the lungs. Breastfeeding in water. The stomach is divided into 4 chambers. Cetaceans have a very long lifespan, with the shortest lifespan in the natural environment being as short as twenty years and as long as ninety years old. It generally feeds on mollusks, fish and zooplankton, and some species can also prey on seals, fur seals, etc. Every once in a while, it must be ventilated.
Cetaceans also add a strong stroke in the continuous development of biomimicry, human invention of sonar is invented through the whale and dolphin sonar principle invented, their sonar system has a clear division of labor, some for positioning, some for communication, some for alarms, and there are special functions of modulating the bit phase by frequency modulation. The sonar performance of these animals living in the depths of the ocean is far beyond the reach of modern human technology.
<h1 class= "pgc-h-center-line" > explore the true meaning of evolution in the torrent of history</h1>
Evolution, also known as evolution, in biology refers to the change of genetic traits in a population between generations
Ancient whales had limbs because they grew on land and adapted to the terrestrial environment; they covered them with long hairs to adapt to the seasonal temperatures on land; and they had tails to maintain balance in their movements on land. They mostly feed on aquatic organisms, so they mostly live at the water's edge.
However, after about 50 million years ago, they gradually entered the water to live, and since then their living habits have changed from terrestrial to completely aquatic, and the drastic environmental differences have made whales undergo significant changes in physiology and structure. In order to better march underwater, their front legs turn into fins, in order to reduce resistance, the hind legs and buttocks gradually disappear, the hairs that were originally covered in the epidermis disappear, and the subcutaneous fat layer thickens in order to maintain warmth, and the long dive allows them to develop the ability of echolocation.
Natural selection, survival of the fittest
The world's species are in the process of evolution, the result of evolution is nothing more than adaptation, speciation or extinction, ancient cetaceans are like this, ancient whales in order to adapt to the ocean gradually evolved new species, the current cetaceans were born, ancient cetaceans extinction. In fact, the evolutionary history of species is equivalent to a cruel history of extinction, and whenever the world cheers for a new species, He has noticed the tears of the deceased. Natural selection, survival of the fittest, although the truth, is still too cruel, and when you face the birth of a new species, you must accept the death of countless species behind its evolution.
Ancient cetaceans seem to have given up the land they depend on to survive to wade into the dangerous oceans for evolution, for exploration, they travel from the ocean to the rest of the world, their figures are all over the world, and they are constantly evolving in exploration. Each fossil is not only a corpse, not only a research material, but also their honor, they use their bodies to explore the way for all things, and their glory is worth remembering the world.
If you can't learn, if you don't know, you can ask
Ancient cetaceans have a spirit worth learning from us, we should learn from their insistence on "thousands of tao, although hard, blowing out the wild sand to gold", learning from their tenacity of "a thousand grinding blows and strong, Ren'er's east, west, south, north and south winds", learning from their "although the tao is long, it is not feasible; Although things are small, they are not impossible", learn from their fearlessness of "soaring incense through Chang'an, and carrying golden armor all over the city". They are the guiding lights on the way forward for mankind, the strong wind that blows away the fog, and a monument that will never fall.
#图片源自网络
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