There are some extraordinarily grand truths in nature,
Sometimes contrary to human cognition and feeling,
So you might think abstract —
Today we're going to illustrate one of these examples.
In your opinion, this may be "counterintuitive",
So please be mentally prepared.
Photo Central noodle-like organism is Angiostrongylus cantonensis growing from the pulmonary arteries of rats
Photograph by HEATHER STOCKDALE WALDEN
"Why should something so disgusting be protected?"
Ugly, slimy, soft,
Vicious, all kinds of damage, causing strong discomfort,
Ghostly, pervasive, multi-pronged, twisting
……
Referring to parasites,
Most people think of these words first.
Indeed, their behavior is really unbearable,
It's hard not to hate or disgust, for example—
Clematis larvae infiltrate the crickets and grow inside them. The worms need water to mate, so they drive crickets to jump into streams, a vicious and cruel move that also provides an important food source for fish.
摄影：ANAND VARMA, NAT GEO IMAGE COLLECTION
(※ Friendly reminder: The clematis in the gif below is too intuitive, or causes discomfort, and can be quickly slid over)
On the cover of the November 2014 issue, Dinocampus coccinellae lays eggs in ladybirds, where ladybird cocoon bee larvae develop and, when mature, crawl out of the still-alive ladybirds and form cocoons around them.
Parasites really want to take bamboo shoots and shoots – but in fact, the place of parasites in nature is as important as those animals that look good! If all the parasites are wiped out, it means that the planet is facing destruction – and there are now many parasites that are extinct or on the verge of extinction (some even think this is "good news").
The order Endpod is a tiny aquatic crustacean that has been invaded by spinosaur larvae. The ultimate goal of Echinacea is to enter the seabird, so it changes the brain of the endpod, driving it towards bright and open spaces, making it easier for birds to prey on.
It takes a lot of courage to protect parasites that look disgusting, and Chelsea Wood, a parasitic ecologist at the University of Washington, is one such courageous man who is the leader of the New Conservation Movement, which aims to save the "unattractive" small animals on The Planet. Under Wood's research, we understand these:
Nearly half of the known animals on Earth —
It's all parasites!
climate change, disappearance of hosts, deliberate elimination,
Cause the parasite to be in the next 50 years —
1/10 of its total is destined for extinction.
In the IUCN Red List of Threatened Species,
There are more than 37,000 critically endangered species,
But there are almost no places for parasites inside,
tens of thousands of critically endangered species registered,
Only one type of lice and some freshwater mussels are parasites,
You can imagine how unpopular the parasitic group is.
Parasitic trematodes are associated with the deformation of the limbs of frogs, and this American bullfrog has been brutally killed. The parasite can live in a variety of animal hosts throughout its lifetime, including tadpoles.
Skylar Hopkins, an ecologist at North Carolina State University, who brought together a group of scientists interested in protecting parasites, published the first global plan to save parasites in a special issue of the journal Bioprotection in October 2020.
"Millions of parasites are threatened, and many may be extinct; but oddly enough, we have barely recorded their extinction." Skylar Hopkins said.
Manipulated by a parasitic wasp larvae, the silver-bellied spider (Leucauge Argyra) forms a special "cocoon-like web" in which the wasp larvae live until the wasp grows.
Photographed by Anand Varma
Many parasites are critically endangered because of their hosts,
It is already in jeopardy.
For example, the endangered pygmy pig sucker. They live only in another critically endangered species, the pygmy pig, which is disappearing from the steppes of the Himalayas, and the pygmy pig sucker is in danger;
In the 1970s, scientists desperately wanted to save them, so they began to keep this bird in captivity, but the lice endemic to the California condor bird were considered harmful to birds (unidentified), and in order to "protect" the birds, scientists used insecticides to eliminate them. Decades later, decades later, in 2015, the Condor was still "critically endangered," while the California Condor was never seen again.
Critically endangered species, the Condor of California
Photograph by JOEL SARTORE
Do you think parasites are just greedily possessing, taking and abandoning? In the case of the disgusting clematis in the past: After the crickets mature, they need to mate in the water, so they affect the cricket's brain and drive the crickets to jump into streams, which is too despicable – but this move provides an important food source for the trout, and the increase in trout benefits its predators in the upper reaches of the food chain.
The human body is also an excellent host for parasites, and more than 100 species of parasites have evolved layer by layer and have long since infiltrated our bodies. Pictured is taken from the patient's eye, sucking nematode (Thelazia gulosa)
Courtesy of CDC
Some sort of sucking nematode may be found on the surface of the patient's eyelid (Thelazia gulosa)
Courtesy photo: OHSU OPHTHALMOLOGY
Even for humans, eliminating the parasite is not entirely beneficial. Many countries have eliminated most intestinal parasites; but in countries and regions where they are unable to kill insects, people carry a wide variety of intestinal parasites, and strangely enough, we have almost never heard of those people suffering from autoimmune diseases.
There is an idea that the human immune system evolved "hand in hand" with a swarm of worms and proto-parasites, and that when we kill them, our immune system is out of balance and instead attacks ourselves. Some people with Crohn's disease (an unexplained intestinal inflammatory disease) have even deliberately infected themselves with intestinal worms in an attempt to restore the ecological balance of the intestine, with mixed results.
In less developed countries, the parasites (whipworms) live in the human gut — a report in the journal Science says they are beneficial to the human body, promoting the growth of a microbiota that reduces the bacteria that cause inflammatory bowel disease and other diseases. Without this parasite, harmful bacteria would be infested.
供图：DENNIS KUNKEL MICROSCOPY,SCIENCE SOURCE(COLORED SCANNING ELECTRON MICROGRAPH)
Wanting to get a good meal, not necessarily becoming the top predator like lions and tigers, parasites know this well, they completely quit the "arms race" between predators and prey, and instead choose a "shortcut with high return on small investment", who doesn't want to go on such a comfortable road? So parasitism in nature has been so common since ancient times.
Fossilized parasitic bee cocoons, about 35 million years ago, hundreds of parasitic bee larvae formed cocoons after feeding their hosts and preparing to become adults.
Photo by GEORG OLESCHINSKI
Generated: THOMAS VAN DE KAMP
What would a world without parasites look like?
Seriously, the parasite is indeed too disgusting — for example, even the most committed conservationists would never give the green light to protect guinea worms — that grow within a person's legs to adulthood, up to several meters long, and eventually emerge from the feet without specific treatment, and can only take days to months to slowly pull out, causing incalculable pain. Former U.S. President Jimmy Carter's foundation has set out to eradicate the parasite. And when the Guinea worm disappears completely, no one will miss it.
(※ Friendly reminder: The Guinea worm in the following GIF is too intuitive, or causes discomfort, and can be quickly slid over)
So, the death of a life-dependent is nothing to say, or even worth the effort, but ecologists warn that the total elimination of parasites could mean ecological destruction; without parasite control, the number of some animals will explode—such as invasive species without natural enemies, which are simply not intended to be contained; and others may collapse in the chaos that follows.
The eccentric cordyceps fungus (Ophiocordyceps unilateralis) devoured the host ant and grew from the carcasses of the ants.
Courtesy photo: ALEX WILD
For billions of years, parasitism has evolved as a way of survival, from the smallest and simplest microorganisms to the most complex vertebrates; there are parasitic plants, parasitic birds; there are a variety of worms and insects; and even parasitic mammals , vampire bats. It should be noted that on the 42 main branches of the tree of life known as "gates", as many as 31 "gates" are mostly parasites.
When the parasites are all destroyed,
It is equivalent to cutting off most of the "tree of life".
The ant was infected with a parasitic fungus that turns the ant into a "zombie." The ants are controlled and come to the ground, where the fungus bursts from the body, spreading the spores to more ants.
Bobbi Pritt, medical director of the Human Parasitism Laboratory at the Mayo Clinic Medical Center, is dedicated to studying various parasites and preventing various parasitic diseases, and even such an "anti-insect master" still says something that favors parasites and digs out her heart:
"As a doctor, I support the elimination of parasites where they cause disease and suffering! But if as a biologist, I don't subscribe to the idea of consciously exterminating parasites. ”
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