25 Mar 2022

Millipedes

by Kim Woolcock

It’s spring, and all kinds of creatures are crawling out from under the leaf litter. Including millipedes.

Their name means “thousand legs” (even though only one millipede, Eumillipes persephone, has more than a thousand legs, and it was just discovered in December 2021). Despite their many legs, they are not fast runners, and they cannot bite or sting. To prevent becoming tasty snacks, they have many defenses. The most well-known is their ability to curl into spirals, with their head in the middle.

Coiled Millipede in dry leaf litter
Taken by: Prosthetic Head


Some carry physical weapons. Polyxenid millipedes have interlocking bristles on their butt that they rub off on ants. The bristles get stuck on the ants, who give up attacking the millipede to remove the bristles. The bristles, which are barbed and have grappling hooks at the end, interlock as the ant tries to get them off. Some ants are too entangled to remove them, and die.

Polyxenus lagurus (Diplopoda, Polyxenida). Dundon, England, United Kingdom
Taken by: Andy Murray


But most millipedes carry chemical weapons, stored in the aptly named “repugnatorial glands." Millipedes can produce eight major types of repellent chemicals, from phenols to quinones to hydrogen cyanide (yes, cyanide).

When threatened, some millipedes squeeze muscles around their repugnatorial glands [editor's note: these are glands that drive away predators], dotting their backs with droplets of predator repellent. Others just let their defensive chemicals ooze out and coat their exoskeleton. But some can spray their repellent, up to 50 cm! Large millipedes from Hispaniola are reported to be able to blind chickens. Others, like Glomeris marginata, take a different tack, exuding a sedative similar to Quaalude, which can put wolf spiders to sleep (it also tastes terrible and it’s not known if predators ingest enough to actually fall asleep or if they’re just put off by the bad taste). Just in case, G. marginata includes sticky proteins in its secretions, entangling its would-be predators.

Flat-backed millipedes don’t mess around with bad tastes or smells—they produce hydrogen cyanide. Yes, cyanide, the famously fast-acting, potent poison. Millipedes are immune to it, and they can exude enough to kill birds and mice. Some of these cyanide producers, like Harpaphe haydeniana, are so deadly they have basically only one predator, the beetle Promecognathus laevissimus, which is also immune to cyanide.

Harpaphe haydeniana
Taken by: Franco Folini

All of this makes them sound rather menacing. But down there on the forest floor, protected by their chemical arsenal, they are performing an essential service: they are shredding up the leaf litter, grinding it into tiny pieces and making the nutrients more available for the rest of the food web. A study of the yellow-spotted millipede in BC’s coastal rainforest estimated that it consumes 36% of the annual coniferous litterfall. Just that one species! That is a lot of shredding.


To learn more about tiny creatures and their superpowers, check out my new book It’s Tough to be Tiny, coming out from Flying Eye Books in September, illustrated by Stacey Thomas. It’s full of fun facts about creatures like springtails and cone snails and how they evade predators, hunt for their lunch, and buddy up with bigger creatures for the benefit of both.



Resources
https://www.sciencenews.org/article/millipede-most-legs-eumillipes-persephone
https://blog.nature.org/science/2017/10/17/millipede-protects-itself-cyanide-yellow-spotted-bugs/
https://www.nature.com/articles/s41598-018-19996-6
https://www.pnas.org/doi/full/10.1073/pnas.1500014112
https://www.sciencedirect.com/science/article/pii/S0305197815001167
https://www.loc.gov/everyday-mysteries/zoology/item/how-are-millipedes-and-centipedes-alike-and-how-do-they-differ/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC38244/
https://cdnsciencepub.com/doi/10.1139/x00-014

15 Mar 2022

Why Do Kids Play?

by Anne Munier

Kids doing what kids do best!

Children are playful creatures. This holds true all over the world- whether that’s playing 4-square in the schoolyard, engaging in some shadow tag if you happen to be in Ireland, or maybe partaking in a bit of luksong-baka if you’re in the Philippines (it translates to “jump over the cow”, but don’t worry, no real cows are involved!). Even back in the Middle Ages kids made toys out of wood or stones, and long before then, pre-historic toddlers finger-painted on cave walls. No matter where kids are, a day well spent is a day full of fun.

Twig figurines from the American South-West. Toys have been popular for a long time.

And it’s not just human kids -- lots of animals, especially mammals, grow up playing. Think of otters gliding down mud slides on their bellies, puppies wrestling with sticks, baby goats galloping all over each other and head butting anything in sight- they are clearly having fun! The most play-loving of all may be our closest relatives the chimpanzees and bonobos, who laugh, tickle, wrestle, play with dolls (well, with sticks that they treat like dolls, so I’d say that counts), and spend most of their childhood, well, having fun.

All this to say -- playing is genetically ingrained in humans. Kids have evolved to play.

Humans are in good company when it comes to enjoying some good playtime.

But why?? Generally we evolve attributes that help us to survive, be healthy, and have babies. But for most of our evolutionary history we were hunters and gatherers, and playing could have some serious drawbacks. For instance, play:

-Burns lots of energy, so kids need to eat more food (that can be expensive when you’re foraging and hunting every day for survival)

-Is risky -- have you ever known a kid to get hurt or lost when they’re clambering over rocks or climbing trees or exploring new areas?

-Can be loud, which would have attracted the attention of hungry predators.

Having fun? No, these kids are honing their critical thinking skills and coming up with solutions.

None of this sounds like an evolutionarily good idea! But scientists assure us that the benefits of play far outweigh the downsides, by helping kids to:

-Learn skills- children’s games often mimic adult activities, such as playing with toy tools, caring for stuffies, or building sand castles. Play allows for years of practice before taking on real life responsibilities (of renovating buildings, parenting, or designing houses for example). It also gives kids a chance to figure out what they love doing.

-Be strong! All that running around and climbing and wresting and jumping is great exercise.

-Think critically- learn how to analyze situations, come up with solutions, and then evaluate. Think of playing Capture the Flag: your team decides who does what, and how to react to certain situations (like the other team getting too close to your flag). Then you try it out, and chat about how it all went down afterwards. Critical thinking at its finest!

-Communicate, form friendships, develop confidence, and generally get along with others. Social animals (like humans, apes, or wolves) tend to spend more time playing than other species.

-Come up with solutions to life’s problems while having fun! Which, it turns out, is a far better way to learn than when you’re stressed out and running from a charging predator, say. One study observed a group of chimpanzees who all wanted some bananas that were out of reach. Which one figured out how to manoeuver them down with sticks? The one who had had the opportunity to play with sticks beforehand, learning how to manipulate them!

Science backs all this up. Bear cubs that play the most are the most likely to survive the winter. Playful yellow bellied marmots are most likely to have high status as adults. Girls in Botswana who play at pounding grain when they’re young become better grain-pounders (a very challenging job) when older. And children who play more as kids tend to become adults who are good at making friends and adapting to life’s changes.


Keep playing little bear!

The bigger problem today is that kids seem to have *less* playtime than ever before. There may be lots more organized activities in kids’ lives (sports teams, music lessons, tutoring sessions, what have you), but having time to play whatever they want - not so much. Scientists are learning that this is not good for the physical and mental health of children *or* the adults they become.

So, the next time anyone tells you that you’re wasting time playing around rather than doing something serious with your time, you can let them know that millions of years of evolution aren’t wrong. That play *is* serious business, and one of the most important things you can spend your precious time on!

13 Mar 2022

Antelope Island and Its Famous Residents—the Bison

by Elaine Kachala

Photo by Michael Kachala

It might surprise you to learn that one of the largest free-roaming herds of bison lives in a state park! Recently, I had the incredible experience of visiting Antelope Island State Park. Located in Utah, United States, it’s the largest island in the middle of Great Salt Lake and home to remarkable wildlife.

Great Salt Lake is five times saltier than the ocean—five times! Why so salty, you might ask? The Lake is in a basin (a dip or depression in the Earth’s surface), so there is no natural outlet. Water feeding the Lake from rainfall, rivers, and streams can only leave by evaporation. These sources carry small amounts of salts and minerals left behind and build up over thousands of years. Great Salt Lake is what remains of prehistoric Lake Bonneville, which dates back 30,000 years.

It’s so salty that no species of fish can survive. But brine shrimp and the larvae of brine flies live there, and they attract millions of birds yearly. Antelope Island is a paradise for bird breeding, migration stopovers, and birdwatching.

The Island is also home to antelopes. Well, not actually antelopes. Pronghorns. Although their scientific name means “American antelope goat,” pronghorns aren’t antelope. But in 1843, explorer John C. Freemont called them antelopes and named the Island in their honor because he valued them as a vital food source.

Cool Facts About Bison:

Weight: 900-2000 lbs (408-907 kgs)

Diet: Grass and flowering plants

Speed: 40 mph (64 kph)

Lifespan: 20 years

Natural predators: wolves (no wolves on Antelope Island)

Bison vs. Buffalo: Buffalo are distant cousins. American bison are unique to North America.

Photo by Michael Kachala

But the Island’s most famous residents are bison. These days, between 500-700 bison are roaming free. And it’s all thanks to two conservationists from Utah, William Glassman, and John Dooly. They saw the need to preserve and protect this once-vast herd. Millions of bison used to roam North America. By the late 1800s, hunting brought them close to extinction. In 1893, the two men brought twelve bison to the Island by boat. They became the foundation for one of the oldest and largest herds in the world.

Caution! Don’t Approach the Bison.” Today, you'll see these signs throughout the Park with information about “how close is too close?” If the bison stops grazing, sleeping, or doing other activities to look at you, you're too close! If the bison stares at you and raises its tail, it's about to charge.

We followed the Park’s rules and watched the bison from our car. They were grazing with tails wagging. We stepped out of the car to take a photo, still keeping our distance. But as we watched, even though we were far away, their tails became still; they stopped grazing and looked up. Time to go!

Human history on Antelope Island began with Indigenous peoples. Then explorers, pioneers, and ranchers all called the Island home. In 1981, the State of Utah bought the Island as a state park. Protecting its fragile ecosystem was a top priority. The State partnered with different organizations, such as the Nature Conservancy. Together, they host education and outreach programs.

The annual bison roundup is another protective measure. Horseback riders worldwide register to help round up the bison into corrals for a veterinary check. Visitors can watch! Since there's only enough food and water on the island for 500-700 bison each year, dozens are auctioned at the roundup. They’re sent to other herds around the country to increase genetic diversity. The money from the auction helps raise funds for conservation efforts on the Island.

A lot is happening on Antelope Island. You can learn about science and history. Revel in geologic marvels. Or you can hike, bike, kayak, camp, star-gaze, and more!


References

Canadian Geographic. https://www.canadiangeographic.ca/article/animal-facts-pronghorn

Smithsonian. https://www.si.edu/object/what-makes-great-salt-lake-so-great:yt_csP5KtR72nU

The Nature Conservancy. https://www.nature.org/en-us/get-involved/how-to-help/places-we-protect/the-great-salt-lake-shorelands-preserve/

Utah Government. Antelope Island State Park. https://stateparks.utah.gov/parks/antelope-island/
and https://www.utahtravelsecrets.com/antelopeislandstatepark.html

Utah Government. History To Go. https://historytogo.utah.gov/lake-bonneville/

Utah History Encyclopedia. https://www.uen.org/utah_history_encyclopedia/l/LAKE_BONNEVILLE.shtml

Utah Government. State Parks. Antelope Island. https://stateparks.utah.gov/stateparks/wp-content/uploads/sites/26/2015/02/AISP-Ed-Packet-History.pdf

Utah Government. State Parks. Antelope Island State Park Junior Ranger Activity Guide. https://stateparks.utah.gov/wp-content/uploads/sites/13/2019/05/AISP-Jr.-Ranger-Booklet.pdf


4 Mar 2022

The Other Entanglement

 
A year ago I wrote a blog entry which included  “entanglement” – a complicated quantum mechanics concept where multiple particles … never mind. (If you’re interested, go and look for the February 2021 blog “Schroedinger’s Bird ??????”.

This other entanglement is more easily understood. Why does hair tangle and how do you get it untangled?

When you look at hair under a microscope, you can see that the core of the hair is covered with cuticles. Think of them as being like the scales of a fish. Both the cuticles and the core of the hair are made up of keratin – helix-shaped protein molecules. The cuticles are covered with sebum, an oily substance which protects the hair from drying out. 

 

                                         A single human hair, showing the cuticles

Because hairs are not smooth, if two meet at the right (wrong?) angle, they can snag on each other. If hair is damaged, cuticles may be missing, torn, or more protruding, and the tangling will be worse. Not all hair is the same, of course. Hair ranges from fine to coarse in thickness, and from straight to curly. It’s not a simple problem to figure out what hair will tangle more. A head of hundreds of thousands of strands colliding in all directions is just the sort of knotty problem that mathematicians and physicists love to tackle. Some fine work done by Jean-Baptiste Masson, a brain imaging researcher at the École Polytechnique in France showed that, although curly hairs cross more often than straight, the angle at which the hairs meet is most important. Counter-intuitively, straight hair tangles more than curly. And what appears to be the most important factor is the diameter of the strands. Fine hair tangles more than coarse hair.

 How to Untangle Hair

 Less surprising than the study of what hair tangles most, is the result of work done by a team of scientists at Harvard. They found — drum roll, please — that untangling hair is best done by starting to comb close to the ends and then working your way up to the scalp.

You can also get some help from the magic of chemistry. There are dozens of commercial Detangling Sprays available. My favourite — based solely on the name — is this one:


 The name is based on the widespread myth in Southern Africa that elephants eat the fermented fruit of the Marula tree, get drunk on the alcohol, and rampage around, causing widespread destruction. And of course, what could be more effective at detangling your hair than a rampaging drunken elephant?

The active ingredients in detangling sprays are

  • Oils. These replace missing sebum, making hair softer and less likely to tangle.
  • Silicone. A substance with long molecular chains that bind to the surface of the hair and make it glossy, smooth and less likely to tangle.
  • Acidifiers. Lowering the pH of the hair strengthens the hydrogen bonds between keratin molecules. This smooths and tightens the surface cuticles on each strand.
  • Hydrolyzed Protein. Amino acids which are the building blocks of proteins. These help to repair damaged keratin, smoothing broken edges of the cuticles.
  • Surfactants. These molecules have one part which binds to the exposed keratin, between damaged cuticles; the other end of the molecule is hydrophobic (repelling water) and creating a smooth thin film that’s easier to comb.
 Preventing tangles – Shampoo and Conditioner

Shampoos are detergents which do one simple job: remove dirt from hair. The dirt is caught up in the oily sebum and the detergent washes it away. Detergents are molecules with one end which is attracted to oil and the other end attracted to water. So one end binds to the dirty, oily sebum and rinsing with water washes away that dirty oil. Any detergent would effectively wash away the dirt. Soap, which is also a detergent, would do that. If you live in Vancouver, which has ‘soft’ water, soap should work quite well instead of shampoo. If you live in Montreal or Kitchener/Waterloo, which have ‘hard’ water, not so much. ‘Hard’ water has dissolved salts of calcium and magnesium, and soap reacts with them to form a deposit: “soap scum”. You don’t really want that coating your hair after you wash it; you need a detergent other than soap.

Some other considerations:

  • shampoos are pH balanced – between 5 and 8. Outside of that range, the cuticles will not lie flat.
  • The detergent must not be too strong. If it is, it will remove all of the sebum, along with the dirt, and your hair will end up too dry.
  •  Shampoos always include a foaming agent. This has absolutely no use except to make the user feel as though the shampoo is working. If the shampoo doesn’t foam, people won’t buy it.

Even with a mild detergent, conditioners are helpful in replacing the sebum that’s been removed. How do conditioners work and what are their active ingredients? Conditioners are actually the same as detanglers, so they are just like that descrition above. Yes, you can use a conditioner as a detangler, especially the conditioners that are designed to be left on your hair and not rinsed off.

Final snippet: 2 in 1 Shampoo & Conditioners are great for saving time. You wash and condition your hair in one step, not two. But how do they work? How does the conditioner “know” that it should wait for the shampoo to remove the sebum before coating the hair? Clever chemistry holds silicones in suspension in a shampoo until the shampoo is rinsed away with a lot of water. So, during the shampooing the silicones are held in a sort of suspended state of animation. When the shampoo is washed out, the silicones are activated, coat the hair and leave it in good condition. The results can be pretty good, but still 2 in 1's can’t match the effectiveness of separate shampoo and conditioner.