Is the sixth mass extinction happening? It seems that no one around us will have such an exclamation, compared with the mass extinction event in history, the current interglacial warm period after the Quaternary ice age is undoubtedly a paradise, the climate is humid and warm, the earth is too peaceful, how can it enter the biological mass extinction?
<h1>What are the causes of the five mass extinctions? </h1>
1, The Ordovician-Silurian extinction event, the time is 445 million years ago to 443 million years ago, about 27% of the family and 57% of the genus exterminated, in terms of quantity, this shot third, because the Gondwana paleocontinental into the Antarctic region, affecting the global circulation, the earth into the Andean-Sahara ice age, biological mass extinction.
2. The extinction event of the late Devonian Period, the time is 375 million years ago to 360 million years ago, about 19% of the families, 50% of the genus are extinct, the time lasts 20 million years, the reason is unknown;
3. Permian-Triassic extinction event, the time is the Permian-Triassic transition period 250 million years ago, about 57% of the families, 83% of the genus extinction, is the largest extinction event in geological history, due to the siberian shield volcano eruption, resulting in the release of methane from the combustible ice in the shallow sea area, together with carbon dioxide caused by an extremely serious greenhouse effect;
4. Triassic-Jurassic extinction event, the time is the Triassic-Jurassic transition period 200 million years ago. About 23% of the families and 48% of the genus are extinct, the cause of which cannot be determined;
5. The Cretaceous-Paleogene extinction event, which occurred 66 million years ago, was about 17% of families and 50% of the genera became extinct due to asteroid impact events.
It is generally believed that these mass extinction events in addition to volcanic eruptions caused by global warming, or ocean currents interrupted into the ice age, there are asteroid impacts leading to extinction, as well as supernova explosions caused by biological extinctions, etc., in addition to supernova explosions and asteroid impacts unpredictable, other extinction events If in the process, then we have already discovered, but so far there is no sign of disaster has come!
<h1>Why is it that we are now in the midst of a mass extinction? </h1>
On 2 June 2020, the BBC published a report titled "Earth Faces Sixth Mass Extinction Endangers the Continuation of Human Survival Civilization", which revealed a frightening statistic that since the Industrial Revolution, the rate of extinction of species has been accelerated by 100 times faster than the rate of natural elimination, and 75 species have gone extinct every day in the world, 3 per hour!
And this rate has reached or even exceeded the rate of the mass extinction period, because the cycle of mass extinction events is very long, such as the late Devonian extinction event 375 million years ago to 360 million years ago, the event is as long as 20 million years, if at the current rate, the species are not even enough to go extinct!
Professor Geraldo Hibalos of the National University of Mexico believes that regional ecosystems are in danger of collapsing, that the sixth mass extinction event is taking place on Earth, and that the factor responsible for all this is humanity, and that our expansion since the interglacial warm period is the beginning of this extinction, and the Industrial Revolution has greatly accelerated this process!
How does human expansion affect species extinction?
Wallace, a biologist at the University of Nevada at Reno, tells the story of a graduate student who studied amphibians in Panama with his classmate Richards-Zavacci, and his subject was the glass frog (a species of the family Apocynaceae), a nocturnal frog with transparent skin and bulging eyes, webbed feet, and usually moving in trees.
The frogs were everywhere around their research site, and of course dozens of different species could be found at the same time, harvesting every night, but after only a few short years, they went out at night to find the glass frog for a long time, and some glass frogs that had been lost and were about to die, and their research turned to why these frogs suddenly died on a large scale.
Later, Wallace found that a frog chytrid fungus infected frogs, only a deadly fungus with strong adaptability and rapid mutation, and the mortality rate of frogs after infection was almost 100%, but where did this fungus come from?
Scan for Chytrid frog fungus under electron microscopy
In May 2018, the mystery was solved, and the journal Science published an article on the origin of Chytrid frog fungus, revealing this secret, scientists from Asia, Europe, North America, South America, Africa and Australia, obtained the genomes of 177 strains, comparative analysis, the results found that the global strain of Chytrid frog fungus origin spread 50 years ago to 120 years ago, and this time period coincided with the period when global trade began to develop rapidly!
Global spread of Chytrid frog fungus
This kind of frog chysodium fungus infected by frogs in the depths of the distant rainforest, indisputable, unknown frogs, the culprit is actually human, in the past century, human trade actions brought about countless cases of biological invasion, such as The European hairy crab is brought to the Ballast water of the Ship Ballast Water of the Chinese Trade, the Florida Burmese Python Flood is brought over by the pet trade, and the Australian hare flood is brought over as a hunting object.
Schematic diagram of the life history of The frog chytrid fungus
Of course, there are many in the name of scientific research, such as laboratory animals, and the practical need to breed them, bringing these animals to the world, so that bacteria that could not cross the continent are on the fast track of global trade, so this is one of the most typical cases of human beings influencing animals around the world.
How many species are endangered or extinct as a result of human activities?
The extinction of the passenger pigeon is more typical, it was eaten by the Americans, once up to 50 to 10 billion passenger pigeon population, actually in less than 100 years, was eaten clean, the price is as low as 1 cent, and even can not be sold is dumped into the garbage dump, far away can smell the smell of the sky!
Of course, there is also the Stella sea cow that was eaten extinct because it was too delicious, and it was mistakenly called Tesla sea cow by many people, but everyone also knows what is going on. There are also dodo birds that are eaten extinct because they are delicious... These are all good things that humans did before and after the Industrial Revolution.
So now? Such low-level mistakes will not be made, but in fact, it is still happening, such as elephants, humans covet its tusks and slaughter in large quantities, especially during the African Civil War, the illegal ivory trade in exchange for arms, as well as endangered rhinos, California Bay porpoises, etc. are caused by certain trades.
More are squeezed by human expansion, such as the golden marmoset, ethiopian wolf, Javan rhinoceros, Spanish imperial eagle, yellow-eared parakeet, Ganga crocodile, Mesoamerican green black spotted poisonous frog and so on. The most typical and ironic is a kind of "Delhi sand love flower fly" living in the Delhi Dunes area of San Bonardino County, west of Los Angeles, California, which only lives here, while the continuous expansion of California has left them with less than 3 square kilometers of living space.
Later, it was urgently listed on the conservation list by the U.S. Fish and Wildlife Service, and a hospital that was building a parking lot here was suddenly suspended and built in the other direction, and this is the super widespread "The United States lost $4 million to protect 8 flies" circulating on the Internet, although a bit exaggerated, but 50% true!
Delhi Sands Loves Flower Fly Recovery Map
What if it is not on the Conservation List? So please ask if these "Delhi Sands Flower Fly" are already extinct, and how many species we have not found, perhaps they have long been extinct in our list of flora and fauna. How many cases of such extinctions there are, we can't possibly know!
How the future will develop, we don't know whether it will get hot or cold
The rate at which carbon dioxide has been emitted since the industrial revolution is about tens of times higher than the rate at which carbon dioxide was accumulated during the Carney Flood Period (an event that propelled the dinosaurs to the stage of history about 230 million years ago), according to which human beings can reach carbon dioxide emissions during the Carney Flood Period in about the next few hundred years, and the result of that year is heavy rains, a global average temperature increase of 5 degrees Celsius, and the surface waters of the equatorial Pacific Ocean reaching 40 degrees Celsius.
Animals that could not adapt to the sweltering weather have gone extinct, but dinosaurs have adapted to this era, and ruled the earth for the next 160 million years, for the earth, there will eventually be a creature on the stage of history, but the future is not human, it is really difficult to say!
Interestingly, a recent study by the Potsdam Institute for Climate Impact Studies shows that due to global warming, the North Atlantic warm current has weakened by about 15% since 1800, and the large beginning of the weakening began in 1950, which echoes the development of global industrialization.
The result of its weakening will cause the northern hemisphere to become colder and may restart the ice age, which will also make human survival into a fairly simple moment, because until now human beings are still in the era of agriculture, still unable to get rid of the sun, if there is a real ice age, then the future days will be sad.
But neither is a good outcome, and as the various ecosystems deteriorate, the arrival of various ecological tipping points, it should come or will come, this is how it will appear, how long it will last, and how big it is, and there may not be a scientist who can assess it.