Vacuuming up eDNA

 by Yolanda Ridge

In crime shows the first thing detectives look for is fingerprints. I’m sure you know why —because every person has a unique pattern on the tips of their fingers. This means anything touched by the criminal could help to identify them.

 

Smart criminals wear gloves for exactly this reason. To stay one step ahead, detectives and scientists figured out how to look for something else that’s unique — DNA fingerprints.

What is DNA? It’s the alphabet used to write the instruction manual on how all living things develop, grow and function. A copy of this instruction manual is contained in every single cell of our body. Which means that if a criminal leaves a piece of hair of a speck of spit at the scene of the crime, scientists can examine the DNA within the cells to try and identify a suspect.

DNA fingerprinting has been available for a while but now there’s something new on the scene — environmental DNA. Better known as eDNA, environmental DNA is DNA that’s been shed by an organism into the environment. And it’s found almost everywhere — water, soil, ice and even air.

 

 

Environmental DNA is not being used to fight crime — at least not yet. But over the past ten years it’s been used to do some cool stuff including:

• verify a new whale species in Mexico

• monitor endangered fish species like the dwarf Galactus in Australia

• determine whether there’s enough food for tigers in Bhutan

• research biodiversity and native species in areas like Columbia

• track polar bear populations and movement in the arctic

• detect invasive species such as Asian carp, American bullfrogs and New Zealand mudsnails

• detect microbes dangerous to plant, animal and human health in waterways around the world

More recently, scientists showed they could vacuum eDNA directly from the sky. To prove it, two different research groups identified DNA from animals at a nearby zoo in samples of the air.

 

To find out more about eDNA, check out these YouTube videos:

1. EnviroDNA (Australia): https://www.youtube.com/watch?v=TQdTV1rAlWY

2. From the World Wildlife Fund: https://www.youtube.com/watch?v=4YXfZvEvUgc

And keep following science blogs like this to learn more about how eDNA gets used in the future. It’s coming soon to a crime scene near you (but hopefully not too near you!).

Yolanda Ridge is a middle grade author, science writer and knowledge translation co-ordinator from Rossland, BC. Visit her website at www.yolandaridge.com to find out more.

Photo credits:

Fingerprint image by Stux from pixabay.com

DNA by Jerome Walker from Wikimedia Commons

eDNA image from Biological Conservation via ScienceDirect

Cloud DNA by Andrew Brumagen via Freethink

References:

https://doi.org/10.1016/j.biocon.2014.11.019

https://www.freethink.com/environment/environmental-dna-whale

https://www.science.org/content/article/dna-pulled-thin-air-identifies-nearby-animals

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiz6Ob40Kr0AhUBHzQIHR5lDP8QFnoECAMQAw&url=https%3A%2F%2Fwww.usbr.gov%2Fresearch%2Fprojects%2Fdownload_product.cfm%3Fid%3D2513&usg=AOvVaw07mx_aLfvVMelg5lPygWdF

 

Testing for COVID-19

By Yolanda Ridge

It’s hard to write about the science of COVID-19 right now because our understanding of the virus is still evolving. But it’s also hard to think about anything else.

One thing everyone wants to know is how and when this pandemic will end. In the best-case scenario, a vaccine becomes available and life goes on as normal. The problem is that it will take at least a year – even with international cooperation, dedication and determination – to develop, test, and then distribute the vaccine worldwide.

To find out more about viruses and vaccines, click on this link to read Virus VS Bacteria – Know Your Enemy on Sci/Why, written by our own Adrienne Montgomerie.

In the meantime, everyone will have to stay at home unless we can find a way to quickly and accurately identity who has the virus and who doesn’t. Unfortunately, testing for COVID-19 has been difficult.

There are two main steps to testing a person to see if they’ve been infected with COVID-19.

Step One: Collect the Sample

The sample must be collected by someone wearing a mask that can protect them from getting infected. It’s done with a nasopharyngeal swab, which is basically a long cotton swab that goes into the nose. 

Photo by cottonbro from Pexels

Unfortunately, both face masks and swabs have been in short supply due to huge demand and manufacturing disruptions. One of the largest makers of nasopharyngeal swabs is in Lombardy, Italy where a lot of people are affected with COVID-19.

Step Two: Test the Sample

Getting enough lab space to do the testing has been difficult as well, since the lab has to be specially designed so the virus won’t spread. The test itself requires specific chemicals and machines, which have also been in short supply.

To find out whether there’s any COVID-19 virus in the sample, scientists look for its RNA. Like DNA in humans, RNA is a set of instructions that makes each type of virus unique. To cause an infection, the COVID-19 virus injects this genetic material into a human cell (it really likes lung cells) along with instructions on how to make copies of it. This allows the RNA to be copied over and over again until the cell dies. Then all those copies of RNA are released in the form of new COVID-19 viruses that can attack other cells.

To find out more, click on this link to watch The Coronavirus Explained & What You Should Do on Kurzgesagt – In a Nutshell.

If someone has the COVID-19 virus, there will be pieces of its RNA in the sample collected during step one. The most common way to test a sample for viral RNA is by something called polymerase chain reaction (PCR). It sounds complicated but PCR is really just way of making more RNA using the virus’s genetic material as a template – not that different to what the virus does itself when it causes an infection. If the virus is in the sample, PCR will produce enough RNA to been seen using a special microscope.

Artist's image of DNA, from the National Institute of Health

Scientists all over the world are trying to find different ways of making step two faster and more efficient. One way is to use CRISPR, a gene editing tool that works like the find and replace function in a word document to change DNA in ways that have never been possible before. With cool names like SHERLOCK and DETECTR, these tests could get results in as little as 5 to 10 minutes by a process that may eventually be used to not only detect the virus but destroy its genetic material as well.

My book, CRISPR: A Powerful Way to Change DNA, comes out this fall from Annick Press. It will go to press before we know how much CRISPR will be used in the fight against COVID-19.

It’s exciting to think about how new technologies might stop future viruses through testing, treating and even developing vaccines. But the current pandemic is teaching us that the supply of basic stuff - masks, swabs, lab space and equipment – is really the most important thing of all.

Whose Remains are These?

by Helen Mason

Battle of Vimy Ridge

This year, Canadians celebrate the 150th anniversary of Canada's birth as a nation. In April, many also celebrated the 100th anniversary of the Battle of Vimy Ridge. During that battle, four Canadian fighting divisions surged up the steep slope to attack German forces at the top. Only one of those divisions failed to meet all its objectives that first day. By April 12, Canadian soldiers and their allies held the heights.

George William Clerihew

Many soldiers died in that battle. One of them was my great uncle, George William Clerihew. He was originally reported as missing in action. After his body was found, it was buried in a military cemetery in France. Family members still visit his grave.

All families are not as lucky. According to the Department of National Defence, 19,000 of the 62,000 Canadian fatalities in World War I remain missing. One of these is Francis (Frank) Bassell Winter, who was part of the 26th (New Brunswick) Battalion of the Canadian Expeditionary Force. Originally from British Guyana, by the start of World War I, Frank lived in St. John with his parents and two sisters: Amy and May. He was the youngest. He joined the armed forces after graduating with a degree in electrical engineering from McGill University.

Francis (Frank) Bassell Winter

Like many Canadian soldiers, this New Brunswick soldier distinguished himself on the battlefield. In July 1916, he was awarded a Medal of Honour for his conspicuous gallantry during a raid on the German trenches. A lieutenant at the time, he was the first person into the German trench and the last person out, even taking time to help bring back the dead and wounded.

He'd been promoted to Captain by the time of the Battle of Hill 70, which was in August. Although the Battle of Hill 70 is little known, it was the beginning of an attack on the French city of Lens. This fight was meant to relieve pressure on the forces fighting near Passchendaele in Flanders. According to historians, the battle marks a turning point in Canadian military history. It was the first time that Canadian forces were led by a Canadian rather than a British general.

Souvenir sent to mother from Amiens.

Rather than attack Lens directly, Sir Arthur Currie, the Canadian general, attacked the hill to the north of Lens, one which dominates access to the area. Canadians charged up the hill on August 15, 1917–and subsequently captured it. The Canadians lost more than 9,000 soldiers in that battle. Of these sixty-nine were never found. One of these was Frank Bassell Winter.

Since he was unmarried and had no children, there were no direct descendants. His parents and sisters mourned his death. Without a body, his family had his name engraved on his mother's tombstone. The family heard nothing more about him until just before Easter of this year when my sister-in-law, Pat Mason, received a phone call from the Department of National Defence. Did she recognize the name Francis Bassell Winter?

What led to this query was the recovery of three human remains near Lens in late August 2016. Such bodies turn up during building or road construction or work in a farmer's field. After almost 100 years underground, much of the identifying material has decomposed. However, certain artefacts may remain, including identifying disks that carry the soldier's name, rank, and unit, cap badges, unit uniforms, rings, and bracelets. Identifying disks can't be used as the only means of identification because a soldier may be carrying the disk of a dead comrade.

Frank was known to have been in the area. In addition, he matched the age and height of the unknown soldiers. To clearly identify the remains, however, the Department of National Defence checks DNA. Much of this is unusable after a century underground. For old remains, identification experts used mitochondrial DNA. This form of DNA is passed from mother to child and from daughter to grandchild. Since Frank had no children, the Department of National Defence worked to trace the descendants of his two sisters.

Tracing female descendants has its difficulties. Sisters marry, change their names, and frequently move. If they don't have female descendants, their line of mitochondrial DNA isn't passed on.

Frank's great niece and great great niece

In Frank's case, his younger sister had gone out West. Fortunately, she had daughters who also had a daughter. Using marriage records and obituaries of family members, research personnel finally traced Frank's great niece to a suburb outside Ottawa.

My sister-in-law was asked to provide a saliva swab so that her mitochondrial DNA could be checked against that in the unknown remains. At Easter, she and her extended family celebrated this possible recovery of a long-dead relative.

Unfortunately, the DNA samples did not match. Frank is not among the three bodies found near Lens. Someday, someone digging in the area may come across his remains. Meanwhile, Casualty Identification staff at the Department of National Defence work to trace the ancestors of other possible matches. Pat's DNA profile will be kept on file for checking against bodies found in the area at some time in the future.

The neighbours of one of my friends had better luck. DND staff identified one set of remains as belonging to an uncle killed during World War I. Family members flew overseas to attend the ceremony when he was interred in the closest British military cemetery that had space.

Helen Mason's most recent books include A Refugee's Journey from Syria and A Refugee's Journey from Afghanistan, both Crabtree Publishing, 2017.

I Blame Dr. Suzuki, or, Why I Write about Science

By Gillian O'Reilly

How did a history and art history graduate end up writing about science? I blame it on Dr. David Suzuki. Specifically, I blame it on a 30-year-old episode of the radio program Quirks and Quarks, which Suzuki hosted, and on a talk he gave to a group of booksellers some 25 years ago. In both cases, the stories he told lodged themselves in a corner of my mind and slowly, slowly pushed science to the forefront of my interests.

The Quirks and Quarks episode was a presentation of ordinary citizens grappling with a new aspect of science in an extraordinarily thoughtful way. It showed a community somewhere in New England faced with a proposal for a laboratory examining recombinant DNA. Back then, for the ordinary layperson, recombinant DNA was the stuff of science fiction or nightmares or both. As I recall, Quirks and Quarks broadcast parts of the public hearings over at least two episodes, devoting hours to the topic with very little editorial comment. We simply heard ordinary people informing themselves, working through questions and coming up with their conclusions. The lab was allowed.

When David Suzuki spoke to the booksellers a few years later, he began by discussing the all-too-common idea that science doesn’t have anything to do with one’s day-to-day life. Intellectually, I agreed with Suzuki that this idea was wrong, but, frankly, science didn’t seem to have much to do with my day-to-day life either.

Suzuki pointed out that, when he was a child, he wasn’t allowed to go to the movies or the swimming pool because of polio scares. As someone who had measles before there was a vaccine and who had seen the results of childhood polio in 1980s Africa, his statement hit home for me. He detailed other ways that science had changed his and everyone’s lives, but what I remember was the vaccines – the very ordinary way that children’s lives have been changed in ways today’s kids can scarcely imagine.

Over the years, I have recalled and reflected on the stories Suzuki told, as I gradually became more interested in writing about STEM topics. These two episodes showed both the ways in which ordinary people’s lives can be affected by science and the way ordinary laypeople can grasp and make intelligent decisions about science.

So I write about STEM subjects, not just for the budding scientist, but for the kids who will grow up to be historians or artists or school principals or lawmakers – all of whom will need to understand and make intelligent decisions about the wonderful science around us.

Gillian O’Reilly is the co-author with Cora Lee of The Great Number Rumble, Revised and Updated: A Story of Math in Surprising Places (Annick Press, 2016), illustrated by Lil Crump.

Canada's Only Great Auk

by Jan Thornhill

"Museum" page from The Tragic Tale of the Great Auk (Jan Thornhill)

While working on my new book about the extinction of the "northern penguin," The Tragic Tale of the Great Auk, I became aware that the Royal Ontario Museum (ROM) in Toronto was in possession of Canada's only stuffed one. Hoping to see it, I visited the ROM's brilliant Schad Gallery of Biodiversity, but was disappointed to find no Great Auk, though there was an equally extinct Labrador Duck on display. How sad, I thought, that the regal bird I sought was not on view, was instead tucked away in some dark cupboard, sealed, perhaps, inside a titanium box, safe, but invisible.

The extinct Labrador Duck (John James Audubon)

But a couple of months later, when I arrived at the ROM to talk auks with Oliver Haddrath, the ornithology reasearch technician whose specialty is extinct flightless birds (like the poor Great Auk), I was thrilled to be led out into the same animal diversity gallery where this time—ta da!—behind two layers of glass, there it was, one of the last of the millions of Great Auks that once thrived in the North Atlantic. 

Me and Canada's only Great Auk (Frankie Thornhill)

There are only 78 stuffed Great Auks in the world, almost all held by museums. American museums own a decent chunk of them—eleven—though that number used to be twelve. The twelfth one was once owned by John James Audubon, the American bird painter famous for his Birds of North America book published as a double-elephant portfolio, "elephant" because it had to be big: Audubon presented all of his subjects life size. Though each page is a huge 39.5 inches tall and 28.5 inches wide, the largest birds—cranes, herons, flamingos—had to be doubled over in his compositions to fit. 

Because Audubon painted birds life-size, he had to double
over the biggest ones to make them fit on the pages. 

Audubon included the Great Auk in the book, but he never saw one alive. He had to base his painting on a taxidermy model, a specimen killed in Iceland in 1830 that he bought in London in 1836. 

Audubon's Great Auks

Eventually, Audubon gave has stuffed auk to a birder friend, Jacob Post Giraud Jr., who, in turn, gifted it (along with the rest of his large collection of stuffed birds) to Vassar College in 1867. There, "Audubon's Auk" gathered dust—quite literally—for more than 50 years, until it was found under a lab sink by Dr. L.C. Sanford who had connections to the American Museum of Natural History. Though the college continued to own the bird, Sanford convinced them in 1921 to allow him to send the auk off for renovation and remounting. When it was all spiffy again, it wasn't sent back to Vassar, but was housed instead at the Museum of Natural History in New York, hidden away in a double crate for the next 43 years. 

The friendly face of the Royal Ontario Museum's Great Auk

Though Canada had once been home to the largest Great Auk colony in the world—on Funk Island off the northeast coast of Newfoundland, (there had been no colonies on American soil at all)—by the early Sixties we still had no stuffed Great Auk of our own. The ROM was desperate to find one. Finally, they convinced Vassar to sell them Audubon's auk. In 1965 they paid $12,500 for it (the equivalent of about $100,000 today), and got a stuffed Labrador Duck thrown in for good measure—the same Labrador Duck I had seen on my earlier visit to the museum.

Signs on a door in the ROM's ornithology department (Frankie Thornhill)

Oliver explained that, because bird feathers deteriorate more quickly when subjected to light, the museum only shows off its Great Auk for six months of the year. For the other six months, the Labrador Duck is the star. 

The ROM's Great Auk came from Eldey Island in Iceland,
 the last place these birds nested after a volcanic eruption caused safer Geirfuglasker to sink beneath the waves. (Jan Thornhill)

As thrilling as it was to finally see an actual Great Auk, I couldn't exactly get close to it, displayed, as it was, at a height and behind double panes of glass. But then Oliver led me and my sister, (who had the camera—yay!), into the secret storerooms of the bird department. First he showed us the egg room. The ROM has a lot of bird eggs. In fact, it has roughly 12,000 sets, a "set" being the number of eggs normally laid in a nest. There is a bird skin room, too, where thousands of boneless birds from around the world are laid out in drawers. 

A tiny sample of the ROM's 11,715 bird egg collection (Frankie Thornhill)

These collections are kind of shocking to see, since each skin and each egg represents a life cut short, but almost all were collected long before any of us was born, in an era when there were a) way more birds of all kinds, and b) different attitudes towards killing wildlife. 

For a while there was a question about whether or not museums should waste precious space storing so many skins and eggs, especially when some species are represented by multiple specimens. The ROM's collection wasn't culled, which is fortunate because it has become clear that these lovingly stored remains hold a treasure trove of information that no one a hundred years ago could have imagined: DNA. When the DNA from skins of birds of the same species that were collected in different places, or ones collected from similar locations but years apart, is compared, we can learn a lot about how our world has changed, and how it continues to change. 

Nine of the ROM's 136,350 study skins (Frankie Thornhill)

Similarly, each egg in the collection has documentation of exactly when and where it was collected. These dates, sometimes from more than a hundred years ago, can be compared to the nesting dates of contemporary birds to help us learn how various species are adapting—or not adapting—to climate change. 

Great Auk bones collected on Funk Island (Frankie Thornhill)

Though the eggs and study skins were fascinating and often gorgeous, the pièce de résistance of the tour was yet to come. Without saying anything, Oliver opened a drawer and pulled out a small, nondescript cardboard box. He opened it. It was filled with bones. Great Auk bones. Auk bones that included a skull and upper beak. Which Oliver handed to me. 

Me giddily holding an extinct Great Auk's skull and beak (Frankie Thornhill)

Maybe that doesn't sound like a big deal. But it was. I'd just spent the better part of a year living with the Great Auk, reading about its amazing and tragic history, its connections to prehistoric and First Nations peoples on both sides of the Atlantic, learning about its anatomy, writing about it, drawing it, painting it, dreaming it. I was so familiar with it it had become my totem animal. And I was holding in my hands the head of one that more than two hundred years ago had swum the North Atlantic. Though you can't tell from the photograph, I was so excited my hands were shaking. 

There's only one thing that could have been better. To see an actual, living Great Auk. But, of course, that would be impossible, since the Great Auk has been extinct since 1844. But,wait! Maybe in the future it won't be impossible. Stay tuned for my next post about efforts to resurrect the Great Auk!



I made Great Auk cookies for my book launch!

published by Groundwood Books 

You and Your School Library Need These Books

by Helen Mason

I love reading Science books, especially those written for kids. That's because authors have to know a lot about their topic in order to distill the information into interesting and understandable communications that appeal to young readers. In the following titles, Jennifer Gardy and Tanya Lloyd Kyi make challenging scientific information readily available to young readers. These books should be in every elementary school library — and the collections of all teachers who hope to interest students in modern science.

It's Catching: The Infectious World of Germs and Microbes written by Jennifer Gardy and illustrated by Josh Holinaty (Owl Kids, 2014) uses a combination of text, visuals, and anecdotes to introduce readers to the many germs with which we share this planet.

The author, herself a disease detective, introduces past disease detectives, such as Antonie van Leeuwenhoek, the first person to see the microbial world. She explains that microbes exist both in the world around us and in our own bodies. Some of the details provide the necessary gross factor that kids love.

Without boring the reader, Grady outlines the difference between viruses, bacteria, fungi, and parasites. There's also a dangermeter for diseases that range from the common cold and influenza to malaria and ebola.

Discussing why doctors are so worried about parents who don't have their kids vaccinated against measles? Mention the 165 BCE measles plague that killed off about one-third of Rome's population. Have students of Irish descent? Suggest researching family trees to find out how many have ancestors who came to Canada following the 1845 Irish potato blight.

DNA Detective by Tanya Lloyd Kyi and illustrated by Lil Crump (Annick Press, 2015) is equally interesting. The intro draws kids right into the topic by showing a crime scene. Someone broke into a jewellery store and got away with valuable jewels. The perpetrator wore gloves. One was left at the scene. There are no other clues.

Readers will enjoy trying to pick the culprit from a list of suspects who include the store's manager, bookkeeper, custodian, and two cashiers, as well as three customers (two of them identical twin supermodels), a sales rep, a security guard, the owner of the store next door, and a convicted thief. They can follow the thinking processes of a young detective on her first case as she collects DNA evidence in an effort to identify the culprit. 

The author compares DNA identification to a high-tech fingerprint. Both can be inadvertently left behind and collected from crime scenes. The book includes profiles of past DNA rock stars, such as Gregor Mendel and Rosalind Franklin. A cartoon page or spread at the end of each section brings readers back to the crime in question. The detective outlines what she's learned. In most cases, readers can use this information to eliminate suspects. By the end, the detective — and readers — have their man — er, woman.

Books such as these provide excellent introductions to topics kids will continue to learn about throughout their student years — and likely their entire lives.

Ladies and gentlemen, we have a winner!! (Well, several winners, actually.)

By Claire Eamer

Every now and then, we have to boast about the amazing awesomeness of the Sci/Why crew. After all, somebody's gotta do it. Why not one of us?

So - without further ado - let me announce that my colleague, L.E. Carmichael has won this year's Lane Anderson Award for the best Canadian youth science book published in 2014. Ta da! She earned the award with her book Fuzzy Forensics: DNA Fingerprinting Gets Wild.

Part mystery and part scientific guidebook, Fuzzy Forensics tells the story of cutting-edge science put to work to solve a wildlife crime, how the science works, and why wildlife crime is important. It's both fascinating and fun.



Pretty impressive, eh? But that's not the end of our amazing accomplishments.

In September, Sci/Why blogger and Science Lady, Shar Levine, was presented with a 2015 Alumni Honour Award by her alma mater, the University of Alberta, for her work in advocating for children's science literacy.

Shar's writing partner, Leslie Johnstone, is no slouch either. While Shar was being honoured at the University of Alberta, Leslie was named one of the 100 leaders in education in British Columbia by the University of British Columbia. Besides writing dozens of entertaining science books for kids, in partnership with Shar, Leslie has taught science at Point Grey Secondary School in Vancouver since 1988 and is currently acting vice principal and head of the science department there.

Congratulations to all of our winners!

The Living Rotting Log: An Amazing Diversity of Fungal Life

by Jan Thornhill

The Maple Log 

I was out in the woods a few days ago on a mission—to find enough chanterelles for dinner. My plan was to go in and out as efficiently as possible. No dilly-dallying. No distractions. No paying attention to weird little things. But then I spied a curious little something on a rotting maple log. Closing in on it, I noticed another little something nearby. And then a big something. And then something else. So much for chanterelles for dinner.

The cup fungus, Humaria hemispherica, is hairy on the outside.

These tiny fuzzy cyphelloid cups, Flagelloscypha minutissima, are
less than a millimetre wide and are more closely related to
gilled mushrooms than to the Humaria cup above.

I kept finding things on this log that's been lying on the ground for possibly four or five years. As I continued to add specimens to my basket, I was reminded of an interesting paper that came out of Sweden in 2012. Researchers there had drilled out multiple samples from Norway spruce logs in two separate locations, and at different stages of decay. They carted these sawdust samples off to the lab where DNA was extracted. In the 38 logs studied, they found evidence of almost 2,000 species of fungi. One log harboured an astonishing 398 different species!

Trichaptum biforme is a common hardwood polypore.

This polypore, Inonotus glomeratus, which can be both parasite and
wood decomposer, probably contributed to the death of this maple.

Inspired, my mission changed from finding food to finding as many species as I could on the log, like a mini mycological bioblitz. Of course I wasn't delusional enough to think I would find anywhere near as many species as the Swedish researchers had in their lab. Unlike the researchers with their DNA sequencing, I was limited to collecting only what I could see with my naked eye—the spore-producing fruiting bodies of wood-inhabiting species. Invisible to me was what was going on inside the log, the strands of mycelia of who-knows-how-many other species that might have produced fruiting bodies earlier in the season, or that might do so later. 

Scutellinia or Eyelash Cups are common orange or red discs with dark-haired edges.

Chlorocyboria species are blue-green and stain wood the same colour.

A Succession of Decomposers

In the life of a rotting log, (which, for a large maple like the one I was exploring, can take twenty years to completely decompose into forest soil), there is a succession of different fungi that do the decomposing. These species arrive as wind- or insect-borne spores, or as already growing mycelia that creep into the log from the forest floor. Some of the earliest colonizers may have caused or contributed to the death of the tree. Some, though not pathogens, may have already spread extensively through the dead wood of the tree before it crashed to the ground. Others don't get a foothold until the log has spent several years absorbing moisture from the forest floor. Still others wait until the early decomposers have changed the structure of the wood or its chemical composition. Some, though their mycelia has crept for years through the heartwood, may never actually produce fruit—the mushrooms, crusts, cups, or shelf fungi we can see. 

These Mycena mushrooms were tiny and fragile.

Cyptotrama asprata is a brightly coloured wood decomposer with white gills.

I got intimate with this log for an hour, kneeling and squatting, (and swatting away crowds of relentlessly aggressive mosquitoes), while taking pictures and carving off samples. When I was done, I had a basket full of polypores and toothy crusts, cups and saucers, and a few complete mysteries. I even had a nice selection of actual mushrooms with gills. The basket wasn't heavy. Many of the things I found were tiny, as in only a millimetre or two in size. 

This Bleeding Foot Mycena mushroom has been attacked
by a parasitic Spinellus fusiger mold.

Fuzzy Chromelosporium fulvum is the asexual anamorphic form of a cup fungus. 

39 Species!

Half of my finds needed microscopy and books and the internet to nail them down to species. I've now spent three days at it and my final number of identified fungi species is 32. Most are saprophytes, or wood decayers. Several are parasites, including a mold that attacks small mushrooms. At least one is an anamorph, or asexual form of a completely different looking fungus. I also brought home 7 different myxomycetes, or slime molds, which are unrelated to fungi, but which we fungi fanatics always include in our collections (read about these fascinating guys here)—which brings my grand total to 39 species. Not too shabby!

I found 7 different slime moods, including a Lycogala, or Wolf's Milk
Slime (above) and Ceratiomyxa fruiticulosa, or Coral Slime (below).

But now I'm hooked, and I know I'm going to have to regularly visit this log, and keep a running inventory of the progression of species I find on it during its long journey from recently fallen tree to forest soil. It will be a slow project, but it will be fun, exploring the teeming life on this dead tree.  

Related Reading: 

Discover Magazine's excellent article What Lurks in Logs
My blog post about animal decomposition

Reference:

A. Kubartová et al. (2012). Patterns of fungal communities among andwithin decaying logs, revealed by 454 sequencing. Molecular Ecology, 2:18