What is causing acute hepatitis in healthy children?
Plus, the menace of billions of feral cats and dogs, and gigantic living things that talk and think beneath our feet.
Cases of acute hepatitis of no known cause are making healthy children very sick all around the world. Some kids have needed liver transplants and a few have died.
Is this illness caused by a new virus or an existing one? Why are only some healthy children affected? Could it occur in India? How worried should we be?
I wrote a long article about what we know (and what we don’t) for Mint this week. You can read the article as a PDF here.
The truth about feral cats and dogs.
Last month, there were reports of kangaroos that had been trafficked into North Bengal in India. A forest range officer discovered them in West Bengal after villagers reported seeing strange wild animals. Three kangaroos were recovered. In Australia, there are at least forty million kangaroos, more than there are people.
Outside of Africa, the largest wild hippopotamus population is in Colombia. Drug lord Pablo Escobar kept a few of them as part of his private zoo. After his death, they escaped. Colombian authorities did not bother to track them down. Today, there are around 100 descended from Escobar’s hippos. Scientific reports mention that are the first large herbivores in the region since the late Pleistocene around 100,000 years ago.
Exotic hippos and kangaroos do not threaten their introduced countries in the same way that some other animals do. Dogs and cats are among the most popular pets in the world, but in the wild, they can be a menace to wildlife. Dogs are the most abundant carnivores. There are estimated to be more than a billion dogs worldwide.
I wrote about this menace for Hindustan Times. You can read the piece here, but the gist is this —
In 2020, a report in Down to Earth magazine estimated that there were 60 million dogs in India, of which 35 million were feral. These wild dogs are a threat to wildlife. A research article by Chandrima Home and her team published in Animal Conservation in 2017 found that “dogs attacked 80 species, of which 31 were IUCN Red list threatened species, including four Critically Endangered species… Approximately 68% of the attacks were carried out by dogs unaccompanied by humans.”
India also reports around 20,000 cases of rabies each year, which is the highest number of cases in the world. Feral animals spread other viral, fungal, and bacterial diseases too.
A continent away, in Australia, the management of feral cat and fox populations is a priority of animal conservationists. Writing in The Conversation, Alyson Stobo-Wilson and her colleagues note that “Cats and foxes, for example, have played a big role in most of Australia's 34 mammal extinctions, including the desert rat-kangaroo which rapidly declined once foxes reached their region.”
A research article published in the scientific journal Diversity and Distributions on March 15 by these authors found that foxes and cats kill roughly 700 million reptiles, 510 million birds, and 1.4 billion mammals.
Cats were introduced in Australia likely in the early 1800s and they flourished in open spaces in the absence of large predators. Today, there are over six million cats in Australia of which roughly half are kept as pets and the other half are feral.
Cats kill over two billion animals in Australia each year. These are staggering numbers. Without cat control, many more native animals will likely go extinct in the next few years.
Deciding what to do about feral cats and dogs poses a moral challenge.
These huge living things might be talking and thinking underground
The largest living thing in the world isn’t a tree or an animal, it’s a subterranean fungus that has spread out over many kilometers in Oregon.
It’s been around for a few thousand years, though no one knows for sure quite how old it is. The fungus is underground in a remote forest so until recently no one knew about it. But genetic analysis has confirmed that different parts of the fungal network come from a single organism. It feeds by devouring trees. In season, it fruits edible mushrooms that are a delicacy.
Honey mushrooms spawned by the humongous fungus (USDA)
The fungus has no heart or brain but a decentralized equivalent of circulatory and nervous systems. Stick electrodes in the network and put a plastic block on it and nothing happens. But put wood (which it eats) and there’s a flurry of electrical chatter. It can talk to itself.
So poorly are fungi studied that we have a difficult time classifying them. In India, fungi are taught in botany classes. Some in microbiology because they cause diseases. In March, a study in in PLOS Genetics found a kind of fungus with 17,550 sexes.
Fungi communicate with tree roots through chemical signals that they can sense and respond to. They form mutually beneficial partnerships with the subsurface roots of plants. This vast underground trading network has been called the Wood Wide Web. Even economists study them.
Accepting that there are forms of talking and thinking even on our planet that are alien to our human-centric view might require more than just experiments. It might require humans to reassess the uniqueness of our place in the world.
I wrote at some length about fungi in my column this week for Hindustan Times.
There is a flow of information in fungi that is more rapid than you might imagine just from looking at the structures of their networks. These underground fungal networks are decentralised as far as we know in that they have no brain or heart, but they do perform many of the same functions of nervous and circulatory systems of animals.
Electrical signaling is a hallmark of neurons in the nervous system. But some organisms that don’t have nervous systems also show electrical activity. Many kinds of fungi have demonstrated electrical activity with specific patterns in response to changes in light, chemicals, and stresses in the environment…
In 2018, Andrew Adamatzky at the Unconventional Computing Laboratory in the United Kingdom inserted electrodes into mushrooms and found that their electrical signals changed based on stimuli. Adamatzky hypothesised that fungal signals could be used as a way to read the health status of the soil environment. Fungi could act as living and breathing computers.
The new research on fungal communication that made headlines globally was also conducted by Adamatzky. He found that electrical spikes created by networks of different kinds of fungi can be clustered into discrete units or “words” that show some of the complexity of human language.
But to say that these electrical signals constitute language, we need to know that they have meaning. Adamatzky acknowledges that the spikes in electrical activity might be “phenomenological” which is a fancy way to say that it isn’t language at all. Understandably, there are many skeptics. More research is needed.
Merlin Sheldrake, author of the eminently readable Entangled Life: How Fungi Make Our Worlds, Change Our Minds & Shape Our Futures writes – “Some organisms – like most animals – find food in the world and put it inside their bodies, where it is digested and absorbed. Fungi have a different strategy. They digest the world where it is and then absorb it into their bodies.”
I highly recommend Sheldrake’s book to anyone interested in these wonderful living things.
What I’ve listened to:
A brief episode on Tesla and Musk from one of my favorite podcasts.
Endnotes…
I just finished a very substantive and thought-provoking book on the genetics and inequality. Inequality by Carles Lalueza-Fox is not light, but it is necessary reading.
Here’s an excerpt —
A genetic lesson from the current pandemic is that once again, wealthy people will tend to survive, and in turn, their genes will tend to be overrepresented in the population after the pandemic. This can happen again and again in the future, such as in crises associated with climate change. Coupled with high rates of assortative mating, the link between inequality and biology will gain strength in the future. If wealthy people tend to mate among them, irrespective of their population background, inequality would likely erase genetic differences among the high-status social class. In a globalized world, ethnic identity will be left to the lower classes of society.