Tag: agriculture

Fungi

Frog Lifeboat

They’re on the run from a vicious fungus that has already wiped out as many as 120 species of amphibians in Central America.

2007-01-02: Tomentella is a brain-eating fungus that creates zombie ants. it does not get much better than this.

2008-09-27: This remains one of my favorite TED talks of all time. mycelium++

2011-12-24: Psychedelic Santa Claus. The origins of this most holy of retail holidays. Praise GDP!

Although most people see Christmas as a Christian holiday, most of the symbols and icons we associate with Christmas celebrations are actually derived from the shamanistic traditions of the tribal peoples of pre-Christian Northern Europe. The sacred mushroom of these people was the red and white amanita muscaria mushroom, also known as “fly agaric.” These mushrooms are now commonly seen in books of fairy tales, and are usually associated with magic and fairies. This is because they contain potent hallucinogenic compounds, and were used by ancient peoples for insight and transcendental experiences. Most of the major elements of the modern Christmas celebration, such as Santa Claus, Christmas trees, magical reindeer and the giving of gifts, are originally based upon the traditions surrounding the harvest and consumption of these most sacred mushrooms.

2013-10-29: Peak Phosphorus: it’s a thing, and mushrooms are the solution (cf: Paul Stamets: 6 ways mushrooms can save the world)

2013-11-27: Fungi are vicious. Using poisons and flesh-dissolving enzymes (think: mycological “meat” tenderizers), they can defend their turf from incursions by other fungi.

Battles between mushrooms don’t make a sound, but they’re violent. Good fighters can kill the less-good ones and take over their territories. There are battles royal going on all the time.

Combat between fungal individuals is a bit like war between heaps of spaghetti. The main bodies of fungi are networks of long, thin strands called hyphae that insinuate themselves into anything they can eat: tree trunks, plant roots, dung and so on. Defending a food source or wresting a few more millimeters of turf away from a rival can prolong life. So fungi don’t let a lack of teeth, claws or eyes diminish their ferocity. Boddy studies toadstool-forming basidiomycetes, a group rife with combatants that poison opponents or release enzymes that dissolve their flesh.

2015-06-01: Fungus genders

The picture below may give you a hint about how the bird’s nest fungus got its name. But what it doesn’t show you is the rather fascinating love life that they have, and what this might tell us about where our own sexual preferences come from.

Bird’s nest fungi live in places like rotting trees, dung piles, mulched woodpiles, nursery pots, and various other places; they’ve done quite well in human habitats, and so several species are thriving. When it first sets up shop, a fungus will grow out long filaments all through the body of whatever it’s growing on, gradually digesting it with enzymes that transform wood (or whatever) into simple sugars. The fungus keeps growing until it touches a prospective mate: at this point, the 2 fungi will grow into each other, exchanging not just DNA but entire cell nuclei. The resulting “dikaryotic” (“2-nuclear”) fungus then grows the fruiting bodies that give it its name: little cups with spores in them that look like eggs in a bird’s nest.

These spores aren’t firmly attached: in fact, they’re designed to fly. When a raindrop hits a cup, it will propel the spores outwards (using the cup as a ramp) in all directions. The spores trail long, sticky filaments behind them, which get caught on branches; the (very lightweight) spores then wind around the branch grappling-hook style, leaving them firmly attached and ready to start their new life. The parent, meanwhile, will keep manufacturing more bird’s nests for as long as it has the food and water to keep going.

There’s just one catch: because the spores get distributed by rain, they don’t fly very far, and that means that children of the same parents will end up close by. This means that the fungus has to have some way to avoid inbreeding. (Inbreeding causes bad mutations to build up, in the sort of way that dubious X-Files episodes parodied, and that makes the fungus less able to survive. The non-silly version of this is called “inbreeding depression

The fungi achieve this by being very picky about their mates. Humans come in 2 genders, and these are our “mating compatibility groups.” These fungi, on the other hand, use what’s called a “tetrapolar mating system.” What it means is this: instead of their being one category of gender, each fungus has 2 kinds of gender, with the poetic names “MAT-A” and “MAT-B.” 2 fungi can only mate if both their MAT-A and MAT-B genders are different. And each of these doesn’t just come in 2 varieties – they can have 10s, or even 100s.

(For what comes next, if you want to know the details I highly recommend this paper)

Take Cyathus stercoreus, the “dung-loving bird’s nest” (don’t you love fungus names?), which is one of the most widespread of the bird’s nest fungi. It has 39 different possible MAT-A’s, and 24 MAT-B’s. This means that there are a total of 936 (39×24) different genders, and an arbitrary fungus will be able to mate with 874 (38×23) of them. The children of this mating will be one of 4 possible genders (getting their MAT-A’s and MAT-B’s independently from each parent), and each child would only be physically able to mate with one in 4 of its siblings – the ones which have both a different MAT-A and MAT-B. That means that there’s a 25% chance of successful mating with a relative, compared to a 94% chance with a random fungus it meets in the street. (Or rather, “in a pile of dung,” but that seems a little less romantic) (Unless you’re a fungus)

But to maintain 936 different genders, you need a lot of fungi, and in species that don’t have as many individuals around, we indeed find that the number of distinct genders goes down in time, as various MAT-A and -B variations are no longer present. Cyathus striatus, the fluted bird’s nest, only has 3 MAT-A’s and 11 MAT-B’s – giving strangers only a 61% chance (2×10/3×11) of being able to mate, with siblings still having that 25% chance. And in fact, C. striatus has been showing increased trouble breeding.

There’s one other important difference between fungi and people: these 100s of different genders (the technical term is “mating compatibility groups”) don’t have any differences in their large-scale physical shape. To tell the genders apart, you need genetic testing.

This may give us a hint as to how gender started out in the first place. At the simplest end, we have asexual reproduction: creatures that divide via mitosis and leave it at that. Next, we have creatures that can penetrate each other’s cell walls and exchange nuclei, like these fungi do; that gives them the advantages of cross-breeding. Compared to them, every asexual species is suffering from permanent inbreeding depression, as each creature only “mates” with itself. Then you see the development of things that quickly kill off any attempt to mate with excessively similar creatures, like this system of genders. You could easily imagine the next stage: the genetic variation between the genders starts to get used in building the physical structure of the creature. This opens up the possibility of different genders specializing in various ways, including in parts of the reproductive process – and the rest, as they say, is (pre)history.

But even we mammals haven’t given up on the old systems of genders! Studies in a wide range of species have shown that everything from butterflies to rats will actively avoid mating with anything that smells too much like them. Scents come from a variety of sources, but significantly, many of these scent components are inherited. What we have is a collection of genetic variants that make people who are too closely related to us not smell like prospective mates. This doesn’t physically prevent mating, but as you’ll have noticed above, even the fungi’s rather elaborate system only reduces the inbreeding rate to 25%; an imperfect system is a lot better than no system at all.

So the next time you smell your relatives, think about the mating habits of fungi, and how your pattern of scents may well be the evolutionary remnant of a system of 1000s of different genders that let our earliest ancestors know their kin.

Many thanks to John Baez for the original article (shared below) which sparked my curiosity with its talk of “mating compatibility groups.” Who would have known that fungi could do that? Well, apart from mycologists, I guess.

2014-02-06: MOMA PS 1 will have a mushroom tower this summer. beats a cloud.

opening in late june, 2014 the scheme integrates biological technologies alongside advanced computer-based engineering. using a pioneering method of bio-design, the structure is formed entirely of organic matter. through diverting the natural carbon cycle, the scheme requires no energy, and produces zero CO2 emissions.

2014-04-05: Mushroom packaging

did you know that there are better alternatives to asbestos, like mushrooms? me neither.

2014-12-16: The Mushroom Man. 6000 species in a garage.

Herbarium Rooseveltensis Amanitarum may contain more distinct species than any university or museum. I have well over 6000 collections of Amanita alone

2016-03-05: Fungi withstand Mars

After a year-and-a-half long voyage aboard the International Space Station, a group of fungi collected from Antarctica has proven its ability to withstand harsh, Mars-like conditions. 60% of the cells remained intact, providing new insight for the possibility of life on Mars.

2016-08-07: Fungal networks

The implications of the Wood Wide Web far exceed this basic exchange of goods between plant and fungi, however. The fungal network also allows plants to distribute resources—sugar, nitrogen, and phosphorus—between one another. A dying tree might divest itself of its resources to the benefit of the community, for example, or a young seedling in a heavily shaded understory might be supported with extra resources by its stronger neighbors. Even more remarkably, the network also allows plants to send one another warnings. A plant under attack from aphids can indicate to a nearby plant that it should raise its defensive response before the aphids reach it. It has been known for some time that plants communicate above ground in comparable ways, by means of airborne hormones. But such warnings are more precise in terms of source and recipient when sent by means of the myco-net.

2018-08-02: Amphetamine Parasite

Imagine emerging into the sun after 17 long years spent lying underground, only for your butt to fall off. That ignominious fate regularly befalls America’s cicadas. These bugs spend their youth underground, feeding on roots. After 13 or 17 years of this, they synchronously erupt from the soil in plagues of biblical proportions for a few weeks of song and sex. But on their way out, some of them encounter the spores of a fungus called Massospora.

2019-09-03: Bees Need Meat

Ask an entomologist what makes a bee a bee, and you’ll likely get some version of “bees are just wasps that went vegetarian.” New research shows that isn’t true. Bees are actually omnivores, and their meat is microbes. This finding may open a new window on why bees are in trouble: Anything that disrupts the microbial community in a bee’s food, whether it is high heat linked to climate change, fungicides or another stressor, could be causing developing bees to starve.” “For most people, the idea that microorganisms can qualify as meat is radical. In the past 4 years, Steffan has published a series of papers laying out evidence that microbes are an important part of a variety of food webs, including those that involve bees. Their findings confirm that fungi, bacteria and other microscopic players can fit anywhere in the food web, upending our vision of predator and prey, carnivore and herbivore—and what makes a bee a bee.”

2019-12-28: Dandruff

there is some indication that this fungus can migrate to the pancreas, where it is implicated in the pathogenesis of pancreatic ductal adenocarcinoma, the most common kind of pancreatic cancer (95%), as deadly as an 88 millimeter shell to the head.

2020-01-04: Freedom From Fungus

Why Don’t Humans Have Chestnut-Style Blights and White Nose-Style Syndromes? fungi are responsible for 72% of the local extinctions of animals and 64% among plants. White nose syndrome in bats and Dutch elm disease are 2 high-profile examples of extremely deadly fungal diseases gaining wider ranges through global trade. While each fungus itself is unique, many fungal pathogens share several special abilities that make them especially lethal. Fighting off fungus may be 1 reason why our body temperature is fastened at 37° C.

2020-04-02: Fungus Meat. This is of course not new. Quorn has been around since the 80s.

Fast-growing meshworks of mycelial filaments can replicate meat’s texture, and it’ll eat pretty much any carbon source, including waste from various industrial processes. Decades ago, British-based Quorn was the beginning of this idea, but this year the number of startups planning to put fungus-based alternative proteins in stores and on plates is mushrooming.

2020-08-10: Fungi emit 8x as much CO2 as humanity.

fungal decomposition is one of the largest sources of CO2 emissions, emitting 85 gigatons every year. In 2018, the combustion of fossil fuels by humans emitted 10 gigatons.

2020-08-11: Fungus economics

the fungus coordinated its trading behavior across the network. Kiers identified a strategy of “buy low, sell high.” The fungus actively transported phosphorus — using its dynamic microtubule “motors” — from areas of abundance, where it fetched a low price when exchanged with a plant root, to areas of scarcity, where it was in higher demand and fetched a higher price. By doing so, the fungus was able to transfer a greater proportion of its phosphorus to the plant at the more favorable exchange rate, thus receiving larger quantities of CO2 in return.

2020-09-27: Saving the Bees with fungi. Adding a 1% extract of amadou and reishi to bees’ sugar water reduced deformed wing virus 80x.
2021-05-18: Fungus problemsolvers

Mycelium not only grows into economical networks, it also reshapes itself in response to its environment. From a block of colonised wood, teeming hyphae initially grow out in all directions in search of more food. But when 1 part of the network finds something new to consume – another block of wood, for instance – the rest of the mycelium stops searching, withdraws from fruitless areas and begins thickening the links to the new food source. What’s more, if the hyphae that connect the original block of wood to the newly discovered one are stripped away, and the 2 blocks are placed in a new container to prevent the re-establishment of old pathways, the regrowing mycelium will nevertheless start out of the original block in the direction of the other one: it appears to ‘possess a directional memory, although the basis of this memory is unknown’.

With a decentralized body that grows independently at every extremity, how does a fungus know when to change itself? When a hyphal tip discovers a tasty block of wood, how is this information conveyed to the rest of the network-body? Through chemical transport, perhaps? Fungi are known to produce and respond to chemicals that can act as cues, and mycelial networks transport water and nutrients rapidly through their hyphae in microtubules, which function hydraulically and are highly pressure-sensitive. They can also direct the flow towards particular areas: when it is time to produce a mushroom, for instance, the mycelium propels water into the growing fruit, sometimes under great pressure. A fruiting stinkhorn mushroom can crack through asphalt, exerting a force sufficient to lift 130 kg.

2021-05-22: Antifungal vaccines

Surveillance that identifies serious fungal infections is patchy, and so any number is probably an undercount. But 1 widely shared estimate proposes that there are possibly 300M people infected with fungal diseases worldwide and 1.6M deaths every year—more than malaria, as many as tuberculosis. Just in the US, the CDC estimates that more than 75K people are hospitalized annually for a fungal infection, and another 8.9M people seek an outpatient visit, costing about $7.2B a year. For physicians and epidemiologists, this is surprising and unnerving. Long-standing medical doctrine holds that we are protected from fungi not just by layered immune defenses but because we are mammals, with core temperatures higher than fungi prefer. The cooler outer surfaces of our bodies are at risk of minor assaults—think of athlete’s foot, yeast infections, ringworm—but in people with healthy immune systems, invasive infections have been rare. The best counter to the ravages of fungi is not treatment but prevention: not drugs but vaccines. Right now no vaccine exists for any fungal disease. But the difficulty of treating patients long term with toxic drugs, combined with staggering case numbers, makes finding 1 urgent. And for the first time, 1 might be in sight if not in reach.


2022-08-19: A free textbook on fungi

fungi lack the functionally important terminal sialylation of the glycans that occurs in mammalian cells. So, without engineering, filamentous fungi, despite their other advantages, are not the most suitable microbial hosts for production of recombinant human glycoproteins for therapeutic use. Nevertheless, strategies to prevent proteolysis have already met with some success and new scientific information being generated through genomics and proteomics research will extend the biomanufacturing capabilities of recombinant filamentous fungi, enabling them to express genes encoding multiple proteins, making filamentous fungi even better candidates to produce proteins and protein complexes for therapeutic use

2022-11-14: How Batrachochytrium dendrobatidis spread widely in amphibians

Since the 1970s, the chytrid fungus Batrachochytrium dendrobatidis (Bd) has spread globally amongst amphibian populations, wiping out entire species and decimating others. While the fungus maintained a consistent set of housekeeping genes, Bd tailored the expression of other genes to each host, allowing it to pursue multiple infection strategies. For example, in more-vulnerable species, genes essential for attaching to and invading leukocytes, cells that defend a host from pathogens, were upregulated. In more-resistant species, genes promoting quicker reproduction, perhaps to evade or overwhelm a host’s defenses, were elevated.

Obesity

Riding on the metro in DC, I was informed that the 69M obese in the US are hype. I’m glad the food industry is looking out for me and even providing me with helpful cartoons.
2007-03-31: The obesity gas connection

US citizens are burning 3.7B liters of gas a year more than they did in 1960, because they are much heavier. That’s about $2.2B worth of fuel, and a lot of greenhouse gas emissions.

2007-04-27: Congress promotes obesity through agricultural subsidies. Ever heard of HFCS?
2007-09-11: plus the reduction in burger and fries consumption would cause less brazilian forest to be burned, further reducing emissions.

$1 in real gasoline prices would reduce obesity in the US by 15% after 5 years.

2007-09-18: No comment necessary.

Many 5-passenger vehicles are rated 385 kg, maxing out if their 5 occupants weigh more than 77 kg each. 6 90 kg people would overload the 7-passenger Dodge Grand Caravan minivan.

2008-03-29: More fatties are found, unsurprisingly.

More than 50% of American adults considered to have normal body weight have high body fat percentages — greater than 20% for men and 30% for women — as well as heart and metabolic disturbances. The finding conflicts with the widely held belief that maintaining a normal weight automatically guards against disorders such as high levels of circulating blood fats and a tendency to develop metabolic syndrome, which often leads to type 2 diabetes.

2008-12-22: The war against fat people has begun.
2010-06-08: Fighting obesity with that other staple, security. brilliant!

27% of all Americans ages 17 to 24 are too overweight to join the military. Now, the group of retired military officers that prepared the report is asking Congress to pass a nutrition bill that would make school lunches healthier.

2011-03-25: Obesity deaths

Since 2001, premature death from obesity has exceeded death from malnutrition.

2015-07-27: a large part of the decline is due to people drinking fewer sodas.

Calories consumed daily by the typical American adult, which peaked around 2003, are in the midst of their first sustained decline since federal statistics began to track the subject, more than 40 years ago.

2015-08-11: There are few public health interventions as beneficial as destroying the soft drinks industry.

Coca-Cola, the world’s largest producer of sugary beverages, is backing a new “science-based” solution to the obesity crisis: To maintain a healthy weight, get more exercise and worry less about cutting calories.

The beverage giant has teamed up with influential scientists who are advancing this message in medical journals, at conferences and through social media. To help the scientists get the word out, Coke has provided financial and logistical support to a new nonprofit organization called the Global Energy Balance Network, which promotes the argument that weight-conscious Americans are overly fixated on how much they eat and drink while not paying enough attention to exercise.

2016-03-23: soda taxes are very odd:

Why not just target the output, rather than some random subset of inputs? We could tax obesity if we wanted to. Or if we want to seem less punitive, we could award tax credits to obese people who lose weight. A tax directly pegged to reduced obesity would certainly be a much more efficient way to achieve the stated policy goal of reducing obesity. We are unwilling to humiliate the obese by taxing them directly, and so our chosen policies do less to help…the obese.

2016-12-31: Viral components of obesity?

During the experiment, both groups of chickens consumed the same amount of food. By the end of the experiment, only the chickens infected with the SMAM-1 virus had become fat. However, even though the infected chickens were fatter, they had lower cholesterol and triglyceride levels in their blood than the uninfected birds. “It was quite paradoxical,because if you have a fatter chicken, you would expect them to have greater cholesterol and circulating triglycerides, but instead those levels went in the wrong direction.” Though Dhurandhar and Atkinson have conducted several strong studies showing the contribution of Ad-36 to fatness, skepticism remains. “I remember giving a talk at a conference where I presented 15 different studies in which Ad-36 either caused or was correlated to fatness. At the end of it, a good friend said to me, ‘I just don’t believe it.’ He didn’t give a reason; he just didn’t believe it. People are really stuck on eating and exercise as the only contributors to fatness. But there is more to it.”

2018-08-16: Sugar is everywhere

Yes, we ate more in 1976, but differently. Today, we buy 50% as much fresh milk per person, but 5x more yoghurt, 3x more ice cream and – wait for it – 39x as many dairy desserts. We buy 50% as many eggs as in 1976, but a 33% more breakfast cereals and 2x the cereal snacks; 50% the total potatoes, but 3x the crisps. While our direct purchases of sugar have sharply declined, the sugar we consume in drinks and confectionery is likely to have rocketed (there are purchase numbers only from 1992, at which point they were rising rapidly. Perhaps, as we consumed just 9kcal a day in the form of drinks in 1976, no one thought the numbers were worth collecting.) In other words, the opportunities to load our food with sugar have boomed. As some experts have long proposed, this seems to be the issue.

2022-01-29: The energy balance theory is bogus

“People get fat because they take in more calories than they expend” is wrong. “Consider using the identical logic to describe, say, why people get wealthy. Economists would be embarrassed by a money-balance theory of wealth: People get rich because they take in more money than they spend. Clearly wealthy people did. We know that because they’re wealthy. The increase in wealth is the positive money balance. But this says nothing about how or why they accumulate such wealth. In obesity research, this tautological logic — saying the same thing in two different ways but offering no explanation for either — was allowed to become the central dogmatic truth.“ Then what does cause obesity? “People don’t get fat because they eat too much, consuming more calories than they expend, but because the carbohydrates in their diets — both the quantity of carbohydrates and their quality — establish a hormonal milieu that fosters the accumulation of excess fat.“

2022-08-14: Wegovy uses a hormone to regulate hunger. It’s wildly effective.

Once it becomes obese, the human body tends to push itself to rebound to its previous highest weight. Scientists don’t fully understand why, or how to stop it. Many speculate that our brains have not adjusted to living in a time of plenty. “There’s been a selection bias towards those people who could better protect body weight during times of famine. But now we don’t have a shortage of food.” When a patient stops taking Wegovy, their appetite returns within weeks and they pack on weight. Patients who came off the drug regained 7% of their body weight. “We used to think that behavior causes the weight state, but now we think the weight state actually causes the behavior”.

Beyond malthus

michael lind asserts that yes, 9bn people can subsist on a lifestyle only the rich can afford today. his article has it all: wildscapes, cowless steaks and hover cars. choice quotes include:

Farm sprawl is a far greater threat to the environment than urban sprawl.
The environmentalists who argue that the affluent countries should revert to the unhealthy peasant diet are wrong.
Those worried that genetic engineering will create biological monsters should be reminded that it already has: just look at the degraded creatures that haunt any farm or ranch.
It makes no sense to counsel individuals and nations to adopt austerity in cases in which there are technological solutions to problems created by technology.