The most wonderful thing about nature is that creatures have their own wonderful survival strategies in order to adapt to the environment. For example, cheetahs always catch antelope to fill their stomachs, so this pair of enemies runs faster and faster in the long evolution.
Tips: Brain development refers to the possibility of guiding and exerting the residual cerebral cortex, including content that makes brain functions that were not previously available. Brain development can be divided into physiological development and psychological development.
Humans have evolved more complex brains that can create and use tools to become beings at the top of the food chain. No one thinks that the brain is not a good thing, but the interesting thing is that nature does have creatures that come inversely. They eat their brains in order to become plants, and as a result, they are brought to the human table. It is the sea squirt.
What is a sea squirt?
The sea squirt has a common name, called the sea pineapple, because its adult body looks like a small pineapple, because it has always been attached to the reef on the seabed, so it was initially used as a plant by fishermen.
Tips: Sea squirts are the lowest class of chordates, the body is wrapped in a coat of colloidal or similar plant cellulose components, the chord in the juvenile stage is in the tail, the chord disappears after metamorphosis, the dorsal neural tube degenerates into ganglions, and the gill fissure remains.
In the past, this creature was classified as harmful marine life because it would always attach to the hull, which would not only slow down the ship, but also destroy the hull to accelerate the oxidation of steel. However, later people found that this creature tasted good and began to cultivate artificially.
It is not eaten like seafood, usually after it is dried. The first step is to peel off the hard skin of the sea squirt sea surface, remove the internal organs, season and dry, and then cut into long strips. Because the air drying method is electric heating and air drying, the wave screws can already be used at this time.
Tips: Sea sheath bibimbap is also a rare delicacy, the method is more suitable for Chinese appetite, with crab seeds, shredded lettuce, seaweed, rice mixed in the microwave for a few minutes, and then mixed with some seafood peppers and sesame oil, very delicious.
Of course, adding it to the soup and boiling it tastes better. Because the glycogen content of sea squirts is relatively high, it is very sweet to eat. And its nutritional value is very high, containing a variety of trace elements, so now it is packaged by merchants as a nourishing health care product, selling very hot. However, we are not a food show, the focus is still to see how it changes itself from an animal to a "plant".
Reverse evolution of the sea squirt
Sea squirts belong to the same phylum Chordata as us humans, and this phylum is arguably the most successful creature on Earth today. All the mammals, birds, reptiles, and fish we see are all chordates.
Tips: The central nervous system is composed of the brain and spinal cord and is the most important part of the human nervous system. The central nervous system receives incoming information from all over the body, and after it is integrated and processed, it becomes a coordinated motor outgoing, or stored in the central nervous system to become the neural basis for learning and memory.
The so-called "backorder" is the bone or tissue used to wrap the central nervous system. There are also three subphyla under this phyla , called cephalopods , tail cords , and vertebrates.
Vertebrates are easier to understand, we humans are, the long vertebrae on the back protect the human central nervous system, is the bridge between the brain and the body of the information transmission. The evolution of a spine by an organism means that it has a highly developed nervous system with a brain dedicated to mobilizing physical activity.
The nervous system of cephalozoa and tails is almost meaningless, although it has been differentiated, but the brain is still in a very primary stage, which we call the brain vesicle, the nerves inside are relatively simple, but it can already control the body movements to run around.
Tips: Wenchang fish, about 50 mm long, shaped like a small fish, headless, with thin tips at both ends. The body is flattened and translucent, with a chord throughout the body. There are eye spots at the front end. The mouth is hidden inside the mouth, and there are 38 to 50 limbal tentacles on the edges of the mouth. It has dorsal, breech and caudal fins. The abdomen has 1 pair of abdominal folds.
More typical animals such as the Wenchang fish, this insect-like creature has not yet evolved a spinal cord that wraps nerves, but a spinal cord made of membranes and muscles. He spent his life burrowing into the sand, outcropping his head to prey on plankton passing by.
Perhaps the Wenchang fish will evolve a more developed nervous system in the subsequent evolutionary path, and eventually become a real fish. In this way, Wenchang fish is still relatively "enterprising". But tail animals like sea pineapples have to give up such a good foundation and be at ease to be a "water weed" that flutters with the waves.
Tips: The larvae of the sea squirt resemble small tadpoles, only about 0.5 mm in length, have a relatively developed chord at the tail, and even evolve photoreceptor cells and balance organs on the top of the brain vesicle, which can swim around.
The sea squirt went from a creature that could swim around to a "coral" rooted in stone, undergoing a series of metamorphosis.
As soon as it finds something that can take root, it will fix the tail on it and begin to metamorphose. In this process, its spinal cord will slowly disappear, and the neural tubes in the back will degenerate into ganglia, which can only control part of the body, only the effect of conditioned reflexes. For example, if you touch the sea squirt, it will automatically shrink to avoid danger.
Tips: Chart of the difference between one day and two days of sea squirt. Its juvenile stage is very short, generally not exceeding 12 hours.
At this stage, its tail will slowly disappear, the position of its mouth will move from the head to the side of the body, and all the organs of the body will be reversed 90 degrees or even 180 degrees, mainly depending on the fact that after it is fixed on the stone, the side is facing outward. By this point, it had completely lost its ability to move and could only survive on this stone for the rest of its life.
Usually, only need to open the mouth tube, let the seawater enter and then discharge from the tailpipe, in the process the body's gills will be fed to the body, and the plankton sucked in will be filtered out by the intestine to digest and absorb. This process of transforming oneself from a structurally complex creature into a simple structure is what we call retrograde metamorphosis.
Tips: The sea squirt has transformed itself from a chordate into an invertebrate.
We humans also have the phenomenon of degeneration into part of the tissue during embryonic development, that is, the tail. It shrinks after a month of embryonic development, becoming a tail vertebrae hidden in the buttocks. This "degeneration" is the process by which we discard useless tissue, but the development of the sea squirt is a useful part of degradation.
And not only to turn back into an invertebrate, the sea squirt also has to eat its own brain, that is, the brain bubble that has evolved photosensitive function. Because in addition to the larvae also need to see the way, the adult sea squirt does not need this kind of thing at all.
Tips: The sea squirt also disguises itself, secreting plant-like cellulose on the surface of the body, hardening itself and disguising itself as a harmless "plant" for humans and animals.
Therefore, the brain vesicles of the sea squirt will gradually fall off during the process of development and be eaten by themselves as food. In this way, the carnivorous fish in the ocean will not treat it as a delicacy.
It is no wonder that fishermen would think of it as a plant, but unfortunately, in the face of humans with knives and forks, no matter how much they disguise, they can't hide the fact that they are delicious. Painstaking calculations have been made, but it has not been calculated that a creature called human beings will evolve on land, and it seems that blind moderation is not a perfect philosophy of life.
Of course, it has other very interesting features.
Hermaphrodite sea squirts
There are many varieties of sea squirts, most of which are hermaphrodites, but unlike the self-pollinating plants we know, it does not allow itself to become pregnant, but strict allogeneic fertilization, and the reproductive methods are divided into asexual reproduction and sexual reproduction.
Tips: The common animal of the land snail is also a hermaphrodite. The snail's male reproductive organs include a small sac filled with "love arrows" – which can fire this thin bone missile at any time.
Sea squirts breed most of the year, sometimes year-round. Their sexual reproduction is similar to that of frogs, which are in vitro fertilization. One sea squirt will release an egg, while the other will release sperm cells, and the two will meet along the seabed and develop into larvae on their own after fertilization.
Theoretically, sea squirts could indeed fertilize their own egg cells with their own sperm cells, but it wouldn't happen under natural conditions. Because the sperm cells and egg cells of a sea squirt do not mature at the same time, the two will never meet, so the sexual reproduction carried out by the sea squirt is allogeneic fertilization.
Tips: At present, scholars have also found a fetal sea squirt, which will suck the sperm cells excreted from other sea squirts into the body, and the fertilized eggs grow into larvae under the nutritional supply of the mother, and then be sprayed out of the body by the mother.
As for the way of asexual reproduction, it is somewhat similar to germination and division, which is called budding reproduction. Mature sea squirts will grow like branches bifurcated, growing a small bud that we look like pineapples. These small buds will gradually mature into a complete sea squirt, and then break away from the mother to become a mature individual.
Tips: Sprout reproduction Sprout reproduction, also known as budding, is one of the asexual reproduction methods. The "bud" in "budding reproduction" refers to the larvae that are separated from the mother, not the structure of the real buds (germinated buds) on higher plants.
It can mate, reproduce asexually, and be very productive, making sea squirts creatures that can spread all over the world.
Biologists have paid more and more attention to the sea squirt in recent years because of these characteristics. It has the most primitive eyes, and a vibration receptor like a flagella, and it also repeatedly jumps between chordates and invertebrates, which is simply the best blueprint for studying biological evolution. But there is a special way of living of sea squirts that give scientists hope for organ rebirth.
If you dare to touch it, spray your face with internal organs
While studying a sea squirt attached to the bottom of a ship in the Red Sea, Israeli zoologist Noa Shenkar discovered that a sea squirt called Polycarpa mytiligera spews out its own internal organs when it feels danger. When the scholar touched these sea squirts, he was directly sprayed with gastrointestinal fragments.
Tips: The team stimulated the sea squirts and found that about half of them squirted out part of their stomach, intestines, and rectum when they felt squeezed.
They underwent prolonged stimulation and found that they activated their defense mechanisms on average every 16 seconds, and each time they spewed out about 3 centimeters of internal organs.
The team fed these visceral tissues to several different species of fish and found that even if the fish were hungry, they would spit out quickly after swallowing the viscera of the sea sheath. So it is speculated that certain chemicals in these internal organs can act as a repellent of fish.
Tips: The gecko is a type of lizard with a flattened dorsal abdomen and a body lined with granular scales or warty scales. The fingers and toes are extended, and the skin folds form underneath them, densely covered with glandular hairs, which have the ability to adhere and crawl rapidly on walls, ceilings, or smooth planes
This kind of self-defeating defense mechanism, we see the most is the gecko, more similar to the sea urchin, he will also spit out his own internal organs when in danger to attract the enemy. There is also a horned lizard on land that increases the eye pressure when encountering enemies, and the cornea ruptures and spews out a high column of blood to paste your face. These creatures are able to harm themselves without hesitation because they all have powerful recovery mechanisms.
After losing its internal organs, sea squirts repair their digestive system in just 12 days. Its miraculous ability to repair comes from the blood of the sea squirt, which contains a large amount of metal vanadium, a concentration ten million times that of the ocean. These vanadium bind to blood cells and transform into a hemovanadium protein that can both deliver oxygen and help sea squirts repair damaged organs.
Tips: γ rays (Gamma ray) are rays released when the nuclear energy level transitions backexcitation, and are electromagnetic waves with a wavelength shorter than 0.01 Angstroms. γ rays have strong penetration and can be used in industry for automatic control of flaw detection or assembly lines. γ rays are lethal to cells and are used medically to treat tumors.
Scholars have done experiments in which a sea squirt receives gamma rays that can easily penetrate biological tissue and fragment the DNA in cells. After the sea squirt is irradiated, the powerful regenerative power seems to have failed. But by injecting it with fresh sea squirt blood, the sea squirt regained its restorative function and was rejuvenated within a few days.
Whether this strange protein can help humans is still unknown, after all, for the human body, vanadium has a certain toxicity. So whether this protein can be used by us or not, scientists need to continue to study to give us the answer.
epilogue:
From the perspective of nature, the survival philosophy of the reverse evolution of the sea squirt is not without reason. It is precisely because of its simple body structure that it has enough nutrition to allow itself to operate two sets of reproductive systems, and it can also differentiate itself and reproduce asexually.
Tips: There is a certain controversy about the extinction of dinosaurs, asteroid impact theory, climate change theory, species struggle theory, continental drift theory, geomagnetic change theory, angiosperm poisoning theory, acid rain theory, disease theory, etc. are the reasons for the extinction of dinosaurs proposed by scientists.
But more successful than anyone else, Xiaobian feels that this creature that sent away dinosaurs may be able to send away humans. The Earth's environment is always changing, and whether the temperature rises by a few degrees or decreases by a few degrees, it will greatly affect our fragile species. Whether this kind of moderate way of dealing with the world will be more successful than that of human beings, the future will naturally give us the answer!
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