Koalas Have Fingerprints Just like Humans

2 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know/koalas-have-fingerprints-just-humans

In 1975 police took fingerprints from six chimpanzees and two orangutans housed at zoos in England. They weren’t just looking for a unique souvenir; they were testing to see if any unsolved crimes could be the fault of these banana-eating miscreants.

While these primates ended up being as innocent as they seemed, the police did determine that their fingerprints were indistinguishable from a human’s without careful inspection.

A few years later, in 1996, a different type of mammal came under police suspicions: a koala!

While it makes sense that orangutans and chimpanzees would have fingerprints like us, being some of our closest relatives, koalas are evolutionarily distant from humans. It turns out that fingerprints are an excellent example of convergent evolution, or different species developing similar traits independently from each other.

Another example of convergent evolution is seen in the bony structure supporting both birds’ and bats’ wings.

Fingerprints are thought to serve two purposes. First, they aid in grip, allowing an animal to better hold onto rough surfaces like branches and tree trunks. Second, they increase the sensitivity of our touch and allow us a finer level of perception regarding the textures and shapes of the things we hold.

Why this is useful for humans is obvious. Our hands are made to grasp, hold and manipulate objects. Whether it’s some nuts we foraged for or our Xbox controller, we humans spend all day every day relying on our sensitive sense of touch.

For koalas, it’s not really so different. They are incredibly picky eaters, showing strong preferences for eucalyptus leaves of a certain age. It seems that their fingerprints allow them to thoroughly inspect their food before they chow down.

Police aren’t exactly worried about koala bank robbers, but it is possible that koala fingerprints could be found incidentally at a crime scene and be mistaken for a human’s, making it pretty difficult to find a match.

To read about how fingerprints form, how parts of them are genetic, and why identical twins have different ones, click here!

Why Mosquitos Bite You and How to Make Them Stop

Originally posted here: https://mcgill.ca/oss/article/health-technology/why-mosquitos-bite-you-and-how-make-them-stop
15 minute read

Summertime means hammocks, BBQs, fireworks, and mosquito bites.

At least it does for me. Those rotten little suckers seem to just love me. They’ll flock to me even when there are three other people sitting in my backyard. What is it about my blood that they seem to enjoy so much?!

Let’s take a look at the science behind mosquitos and try to answer two questions: Why do mosquitos bite certain people, and what should we do to make them stop?

Take-home message:
– Blood type may or may not play a role in attracting mosquitos
– Products using DEET, icaridin, PMD, metofluthrin, and some blends of essential oils are effective at repelling mosquitos
– Bug zappers, sonic devices, citrosa plants, B vitamins, and scent-baited traps are not effective at repelling mosquitos and should be avoided

Mosquito isn’t a Species, it’s a Group

Before discussing the nitty-gritty of mosquito attraction, we need to realize something. While we tend to think of all flying bugs with proboscises as mosquitos, in truth there are more than 3500 species categorized into 112 genera that fall under the moniker of mosquito.

With such variation in species comes a lot of variation in habitats, behaviours, and risks. For instance, malaria is transmitted to humans only by mosquitos of the genus Anopheles, while yellow and dengue fever are transmitted by those in the genus Aedes. Canada is home to roughly 82 species of mosquitos belonging to the genera Anopheles, Culex, Aedes, Mansonia, and Culiseta. Some mosquitos are anthropophilic, meaning that they preferentially feed on humans, while others are zoophilic and preferentially feed on animals.

We’re typically taught to remove standing water from our property and avoid boggy or marshy areas (good luck in Ontario) to avoid mosquitos, but some species of these bugs don’t exclusively lay their eggs in water. We tend to think of mosquitos being at their worst in the summer, at dusk and dawn, but different species are active at different times, and their behaviour can even change from season to season, making it hard to predict when we are at risk of getting bitten.

Something that is true of all mosquito species though is that only the females bite. They require a blood meal in order to produce their eggs. The nasty by-product of this reproductive cycle is that they transmit diseases, and actually kill more people per year than any other animal.

How Mosquitos Track You

Mosquitos home in on their dinner-to-be by following a few different signals. The first clue that something biteable is nearby is the detection of a COplume exhaled on the breath of mammals and birds alike.

The amount of CO2, however, does not affect the attractiveness of a specific target, so even if you’re a human who produces more COthan others (such as those who are larger or pregnant) that alone is not responsible for your irresistible-to-mosquitos aura. This makes sense since large animals like cows naturally produce much more COthan humans, yet many mosquito species still prefer to bite us.

Mosquitos will track a CO­plume until they encounter host-cues. These first of these clues that a target is close by is usually smells emanating from the skin, which we’ll discuss more in a second. As they get close to the source of a smell, mosquitos will then detect and head towards heat and moisture signals emanating from a body.

Source: https://www.sciencedirect.com/science/article/pii/S096098221500740X

We don’t know whether changes in body temperature affect how attractive you are to a mosquito, but we do know that sweating increases the volatile compounds on your skin that they love, and that anhidrotic people, or those who show decreased sweating, are less attractive to the pests.

The main mosquito-cues that can differ between humans are the olfactory ones. While it’s easy to swap your shampoo and soap for unscented varieties that won’t attract mosquitos like the sweet-scented ones do, a lot of the smells that mosquitos sense are innate to your physiology and sadly are not something that we can really change.

A few of these odorous chemicals include ammonialactic acidsulcatone, and acetone. For many of these compounds, however, higher concentrations don’t equal greater mosquito attraction. Instead, they modulate the attractiveness of other substances. For instance, lactic acid has been shown to increase mosquitos attraction to ammonia and CO2.

While an animal may produce similar-to-human levels of CO2, humans tend to produce more lactic acid than primates or cows. This lactic acid synergistically increases the appeal of CO2for anthropophilic mosquito species, while actively dissuading zoophilic species from landing on you. Conversely, ruminants like cows also exhale1-octen-3-ol, a substance that attracts zoophilic species of mosquitos. In a demonstration of this, skin rubbings taken from cows were made just as attractive to anthropophilic mosquitos as skin rubbings from humans via the addition of lactic acid.

The Role of Blood Type

There has been significant debate over the role blood type plays in attracting mosquitos. Initially, a 1972 study using Anopheles gambiae found that mosquitos preferred those with O type blood (O>B>A>AB). But a 1976 study using the same mosquito species did not confirm this.

1980 study examined 736 patients and found that while those with A type blood made up 17.6% of the control group, they made up 29% of the malaria cases. Conversely, those with type O blood made up 33% of the control group but only 22% of the malaria cases. While this alone does not tell us whether or not certain blood types are more likely to be bitten by mosquitos or contract malaria, it does point to blood type playing some role in mosquito attraction.

Some clarity came with a 2009 study done with Aedes albopictus that found a similar pattern to the original 1972 study: O>B>AB>A. The researchers also compared the mosquito-attracting ability of those who secrete substances corresponding to their blood type onto their skin, versus those who do not. Their theory was that these blood type-specific secretions could explain mosquito’s ability to find their preferred type O prey. Their results, however, showed an order of preference of O secretors>A nonsecretors>B secretors>O nonsecretors>A secretors>AB secretors>B nonsecretors, which do not correspond to the blood type preferences established.

Concerning blood type’s role in attracting mosquitos, we’re stuck with the often-written phrase more research needed. Given the conflicting results and relatively small sample sizes of these studies, we cannot make definitive conclusions. Not to mention that we have no idea how mosquitos are able to detect a target’s blood type from a distance.

If mosquitos do truly target those with type O blood, the authors of this study theorize that preference could have evolved due to the prevalence of type O blood in African nations. The three most populous African nations are Nigeria, Ethiopia, and Egypt, and the percentage of their populations with type O blood are 51.3%, 39.0%, and 52.0% respectively.

How to Avoid Getting Bitten

Anyways, even if we knew what blood types attract mosquitos, you can’t change your blood type. So, what can you do to get some relief from these minuscule menaces?

First, it’s important to remember that just because you’re not forming welts doesn’t mean you’re not getting bit. Not all bites will lead to the familiar welts, so even if you’re not covered in itchy bumps, if you’re near mosquitos you should be using repellant.

Things That Work

Physical barriers should be your first line of defence against mosquito bites. Install screens on your windows, doors, tents, and RVs, and cover children’s cribs, playpens, and strollers with fine mesh to keep mosquitos out.

You can get specialty meshes and clothing treated with permethrin, an insecticide, for adults in Canada. The anti-mosquito effects of the chemical will last through several wash cycles, but permethrin-treated objects should never be used for or around children, including screens or mosquito nets that they may interact with, as their safety has not been evaluated.

In general, you should strive to wear light coloured clothing, and cover as much of your skin as the heat will allow. Mosquitos are better able to orient themselves towards darker targets, so skip the Nirvana t-shirt and try on a white tee instead.

Flowery and fruity scents will attract mosquitos greatly since they feed on flower nectar (in addition to us) but even non-botanical scented products should be avoided whenever possible. This includes (amongst many others): shampoo, soap, conditioner, shaving cream, aftershave, perfume, deodorant, hand cream, makeup, and even laundry soap and softener.

In terms of repellants, the good news is that you have more options on the market than ever. The bad news is that only some of them work.

DEET

N,N-Diethyl-meta-toluamide, better known as DEET, has been the standard ingredient in commercial bug sprays since 1957 when it made the jump from military to civilian applications. While it used to be thought that DEET interfered with a mosquito’s ability to detect lactic acid, more recent research has found that mosquitos detect and avoid DEET directly. Much like I do with vinegar.

Misguided fears about DEET’s safety have spurred some to move towards other mosquito repellants, and while there are other effectual repellants, none work as well or for as long as DEET. In terms of its safety, DEET has been more thoroughly studied than any other repellant and when used according to guidelines is quite safe.

When utilizing DEET-based repellants it’s important to pay attention to the concentration of DEET in the product. The Government of Canada recommends that no concentration over 30% be used on anyone and that only formulations containing up to 10% be used on children aged two to twelve (up to three daily applications) and aged 6 months to 2 years (only one daily application). Babies under 6 months should be kept mosquito-bite free through the use of nets and screens rather than repellants of any type.

Icaridin 

Icaridin, also known as picaridin, is a safe alternative to DEET popular in Europe and recommended by the Government of Canada for use against mosquitos and ticks on anyone over the age of 6 months. This study showed that products with 9.3% icaridin can repel mosquitos for up to 3 hours, while this study showed that a 10% concentration repelled mosquitos for more than 7 hours. This is comparable to the 5 to 7+ hours of protection provided by 7-15% DEET products, although DEET has been more widely studied. Contrarily this study found a 10% icaridin repellant rather ineffective. If you find them effective, icaridin-based products could be particularly useful for small children who have exceeded their daily recommended applications of DEET-based products but still need to remain outside.

Citronella

Citronella has long been the standard of backyard BBQs and picnics in its candle form, but in addition to the coils and candles designed to keep mosquitos out of a particular area, there are also repellants that contain citronella oil.

Citronella oil is made mostly from 2 species: C. nardusand C. winterianus, and contains many different chemicals, the most notable in terms of their insect-repelling nature include camphor, eucalyptol, eugenol, linaloolgeraniol and citronellal.

While it’s citronellal that provides the flowers with their characteristic lemony scent, a 2008 study’s findings suggest that it is actually linalool and geraniol that provide the bug-repelling effects. The researchers compared candles made of 5% citronella, linalool, and geraniol, and found the geraniol and linalool candles much more successful at repelling mosquitos than normal citronella (85% and 71% versus 29% repellency rates over 3 hours). This study likewise confirmed straight citronella candle’s inability to effectively repel mosquitos alone.

This study examined three mosquito repellants that contained citronella and found them all significantly less effective than formulas containing DEET or icaridin, and this study examined 3 wearable bracelets that claimed to emit geraniol and found them as effective as using no repellant at all.

So while it could be useful to burn a geraniol or linalool candle while you’re sitting outside, you should probably still backup your protection with an effective repellent.

P-Menthane-3,8-diol (PMD)

Products with p-Menthane-3,8-diol, a chemical found in small amounts in oil extracted from the lemon eucalyptus tree, have generally (studies 1,2,3) show it to be as effective as DEET and icaridin. The Canadian government recognizes PMD’s repellency effects on blackflies and mosquitos but recommends against using PMD-containing products on anyone younger than three.

Soybean and Essential Oils 

Soybean oil is perhaps the strangest bug-repelling ingredient on this list, but repellant formulations containing mixes of soybean oil and various essential oils have been rapidly making their way onto the Canadian market. While the soybean oil itself does not repel mosquitos, it works in tandem with the essential oils also included in the repellants to stabilize their volatility.

This study found that a formulation including soybean oil, coconut oil, geranium, and vanillin repelled mosquitos for more than 7.2 hours. However, the same study, and another, showed that other formulations also containing soybean oil, as well as other various essential oils (menthol, eucalyptus, lavender, rosemary, sage, etc.) worked very minimally.

This points to the particular essential oils and other ingredients in the repellant making the difference rather than the soybean oil itself. This makes sense when you consider that the geranium included in the effective soybean repellant was likely citronella, and that vanillin has been shown to increase the repellency effects of citronella.

The Government of Canada doesn’t place any age restrictions on formulas containing soybean oil but recommends not using essential oil formulations on those younger than 2. So, you’re free to experiment with different products using different ingredient blends and see which works, but make sure to turn to something a bit more reliable when actually venturing into the woods.

Metofluthrin 

If you’d rather wear a clip-on device than use a mosquito repelling lotion or spray, your only good option is those that emit metofluthrin. This 2017 study examined the efficacy of 5 wearable anti-mosquito devices and found that only the metofluthrin at a concentration of 31.2% effectively repelled mosquitos. Much like citronella candles, however, clip-on devices work by creating a fog of mosquito-repelling chemicals around you. This means that they will only be effective for times when you’re sitting still.

Things That Don’t Work

While components of citronella oils may be effective repellants, citrosa houseplants are not. Nor are the sonic mosquito repelling products that claim to play sound at frequencies that will drive mosquitos away. I’ll let the authors of this paper sum up the evidence for these products: “We are not aware of any scientific study showing that mosquitoes can be repelled by sound waves and therefore we consider these devices as the modern equivalent of snake oil”.

While synthetic mosquito lures that attract the bugs just as well, if not better, than humans have been developed, in practice mosquitos continue to be attracted to humans even when these devices are used. Thus, their use is not recommended by the Canadian Government. Likewise, handheld or mounted bug zappers certainly exist and can be quite satisfying to use for revenge on the bugs that stole your blood, relying on them for protection is not a good idea.

You may have heard that eating bananas can alternatively make mosquitos more or less attracted to you. The claims of banana’s repelling power stem from their high vitamin B6 content, but a 2005 study tested the effects of vitamin B consumption on mosquito attraction and found absolutely no effects. In terms of bananas attracting power, those claims come from octenol content, a chemical that does indeed attract mosquitos. But, octenol isn’t unique to bananas, it’s found in many foods, and no studies have been done that prove consuming bananas does make you a bug-target, so keep on munching.

A subtler mistake you may make when selecting your mosquito repellant is to use a product that combines sunscreen and bug spray. While certainly convenient, the problem lies in sunscreen’s need to be reapplied much more frequently than mosquito-repellants. If both products are needed for an outing, it’s recommended that you wait 20 minutes between applying sunblock and repellant.

Basically, to avoid being a mosquito-target you should stay as scent-free as possible, wear light clothes, avoid bogs and use an effective repellent (such as those containing DEET or icaridin). Or, you could always stay inside- I hear its quite nice this time of year.

Woofer Madness: Cannabis, Companion Animals and What Legalization Means for Your Pets

7 minute read
Image created by Ada McVean
Originally posted here: https://mcgill.ca/oss/article/health/woofer-madness-cannabis-companion-animals-and-what-legalization-means-your-pets

Take-home message:
– THC is very dangerous to most companion animals
– Medical cannabis has only a few uses in humans, and even fewer in animals
– Cannabis, hemp or CBD treats, food or supplements are not approved or regulated by Health Canada. They are illegal and could be quite dangerous for your pets.

While medical marijuana has been available to varying degrees for decades, with recreational marijuana legalized this week in Canada, discussions about what (if anything) cannabis can treat seem to be at an all-time high (see what I did there?)

Discussions of treating medical problems with cannabis are not limited to humans. If cannabis may benefit humans, it may similarity benefit companion animals like dogs or cats. Considering that some of the major ailments cannabis is touted to treat are prime concerns for pet owners (anxiety, arthritis, pain) it makes sense for pet owners to be curious about cannabis.

Cannabis can be very dangerous for pets

When discussing cannabis and companion animals, it’s important to define a few terms.

Tetrahydrocannabinol or THC is the main psychoactive component of cannabis. As most pet owners aren’t interested in getting their furry friends high, the vast majority of pet-marketed cannabis products are free, or almost free, from THC. Which is good, because THC is quite dangerous for animals.

Since it’s difficult to study cannabis (due to it’s soon-to-expire illegal nature) we lack recent numbers on the dose based effects of THC in dogs. Early studies report intoxication effects in dogs with doses between0.25 and 0.5 mg/kg of body weight. If your average German Shepard is about 30 kg, they would show THC’s effects after ingesting 7.5 – 15 mg, or about a 10th of your average “special” brownie.

Though cannabis intoxication and adverse effects have been reported in other animals like catshorses and ferrets, it’s much more common in dogs. Why? Because dogs like to eat. As Dr Sarah Silcox, the President of the Canadian Association of Veterinary Cannabinoid Medicine explained to me, “edibles, in particular, are very attractive to dogs, and if left within reach of pets, will often be gobbled up quickly.”

Cases of cannabis toxicity in pets have been increasing in States where legalization has occurred. We can expect much the same trend here in Canada. It really can’t be said enough that vigilance is crucial in keeping your pets safe.

While it’s not likely that pets will die from cannabis exposure (through smoke or edibles) there can still be serious effects, especially if left untreated. Fluffy and Rover probably won’t get a kick out of the intoxicating effects of cannabis, given that they can’t understand what’s happening. Pets may experience significant anxiety, agitation or lethargy. Smoke of any kind can cause respiratory distress and potentially lung cancer to pets who inhale it regularly, due to the polyaromatic hydrocarbons created during incomplete combustion. Cats in particular are at risk of developing malignant lymphomas when exposed to secondhand cigarette smoke, a risk that may transfer to other types of smoke. .

So what’s with all the cannabis products for pets then?

Pet treats, foods and supplements in general feature no THC. They instead contain a different cannabinoid found in cannabis: cannabidiol or CBD. CBD is not toxic to animals like THC, and it does not cause the same psychoactive effects.

CBD products for pets are marketed for their pain relievingcalminganti-inflammatorysleep-aiding and anti-nausea effects. But do they work?

We basically don’t know.

This study of 16 dogs with osteoarthritis showed a significant decrease in pain after treatment with CBD oil, but similar studies, or studies looking at cannabis to treat other conditions are seriously lacking.

Dr Silcox mentioned many anecdotes of positive effects of CBD products on pets, and this survey have found that that well over half of all owners polled who have used cannabis products on their pets felt it helped. But anecdotes are never evidence enough. We need good, large, controlled studies to properly evaluate the potential benefits and risks of cannabis products on cats, dogs and other pets.

We can be cautiously hopeful that cannabis could eventually be used in veterinary medicine to treat similar conditions for which it’s showing promise in human trials. The problem is, the list of those conditions is short.

There’s good evidence that cannabis can treat nausea as a side effect of chemotherapy (something dogs do experience), as well as help manage multiple sclerosis (which bears some similarities to the canine disease degenerative myelopathy)

For pain treatment however, the evidence for cannabis hasn’t looked wonderful. This 2015 review found evidence for use of low dose cannabis for neuropathic pain, but not for other pain. This 2018 Cochrane review states that the use of cannabis for “chronic neuropathic pain might be outweighed by their potential harms.”

The outlook for cannabis in treating other conditions like anxiety, non-chemotherapy induced nausea or glaucoma is equally dim: “For most conditions (example anxiety), cannabinoid evidence is sparse (at best), low quality and non-convincing.” Despite claims to the otherwise, there isn’t any convincing evidence of cannabis’ ability to cure cancer either.

I have three main concerns with regards to cannabis and animals. First, with legalization, there will be more cannabis in homes, which means more cannabis in a position to be eaten by pets. In states where legalization has passed cases of cannabis toxicity in pets have increased. There’s no reason to expect a different trend in Canada, something that worries me.

Second, as Dr Silcox wrote, there is a “concern that that pet owners will attempt to medicate their pets with cannabis products and without appropriate guidance, put their pets at risk of adverse effects.” When we give our pets, children or ourselves any medication we first check dosage information, but the problem is that it isn’t available in any well researched, accurate or well-defined way for most species.

Third, pet owners may use cannabis in lieu of other evidence-based treatments, putting their pets at risk or hurting their quality of life. We don’t really know what cannabis can or should be used for in animals, but that hasn’t stopped many owners from using it for things like pain, anxiety management and diabetes management. My fear, simply put, is that owners will choose cannabis over NSAIDS, over other pain killers, over insulin, and even over euthanasia. I hope that no animals are suffering as a result of receiving cannabis as an alternative treatment to conventional veterinary medicine, but my fear is that it’s already happening and will begin to happen more with legalization.

Whether they work or not, they’re illegal and unregulated.

Until October 17th, 2018 all products containing plant-derived cannabinoids (which includes THC and CBD) fall under the Controlled Drugs and Substances Act. But even after the 17th, it isn’t open season for cannabis products. The new Cannabis Act will regulate the approval and sales of cannabis products, meaning that anything sold legally will need to be approved by Health Canada.

Health Canada currently has no products approved for veterinary or animal use. So CBD and cannabis products currently have, as Dr Silcox explains, “no regulatory oversight to ensure their quality, safety, or effectiveness. While they are marketed to treat a range of ailments, these health claims are unsubstantiated by Health Canada, the products are not approved, and as such, are not compliant with Canadian law.”

Now, that could soon change. With legalization around the corner, studies on cannabis and its effects are about to become a lot more feasible. With more evidence we will be able to hash out which CBD claims have merit, and which are baseless.

With entire conferences being held on veterinary use of cannabis we can hopefully expect some answers soon. In the meantime, a few things remain really important.

  1. Knowing the signs of excess cannabis exposure in your pets.
  1. Being open and honest with your veterinarians in regard to your pets cannabis exposure, and your use of CBD supplements with them.
  2. Storing all cannabis (in smokable or edible forms) in non-pet accessible places
  3. Eliminating your pet’s exposure to secondhand smoke

You might enjoy the feeling of being high, but Spot will not. Keep the joint to yourself and feed him a dog biscuit instead.

Your Pet Cat May Be a Bit More Dangerous Than You Think

2 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know-general-science/your-pet-cat-may-be-bit-more-dangerous-you-think

Cat scratch disease (CSD) is an infection resulting from a scratch or bite of a cat (or, in rarer cases, dogs or other animals). It is not the same thing as Cat Scratch Fever, an album by Ted Nugent, although CSD can cause a fever, as well as swollen lymph nodes, lethargy, neuroretinitis and headaches.

CSD is the result of an infection by Bartonella henselae, a bacterium commonly transmitted to cats via the cat flea (yes, cats and dogs usually have different fleas). Rarely, ticks and spiders can also carry the bacterium, and transmit it directly to humans.

Kittens are more likely to carry Bartonella henselae than adult cats due to their underdeveloped immune systems, and are much more likely to bite or scratch their owners while learning how to play gently. But anyone who is exposed to cats of any age should take care to clean any wounds well to avoid risk. Bartonella henselae can also be transmitted to humans via cats’ saliva, so as sweet as it may seem that Fluffy is licking your wounds for you, probably best to wash it and wear a Band-Aid.

For veterinarians, CSD is actually considered an occupational hazard. Vets are frequently in close proximity to many cats, oftentimes cats that are acting aggressively and are more likely to bite or scratch. One study found Bartonella DNA in 32 of the 114 veterinarian patients they tested.

CSD is diagnosed via blood test, or simply by considering the symptoms of the patient, the most obvious of which is a swollen blister or sore and red area surrounding the infected bite or cut. Those who are immunocompromised (such as patients with HIV), very young or very old are more likely to be infected, and rates of infection generally increase during spring in North America, likely due to the birth of many new kittens.

So while they may be as cute as anything, cats do still pose a risk to their owners, and not only because they may destroy your favourite furniture.

The kitty in the picture is named Jean-Charles and he is available for adoption from the Réseau Secours Animal in Monteal now!

Leafcutter Ants are Farmers Who Grow Fungi

2 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know/did-you-know-leafcutter-ants-are-farmers-who-grow-fungi

Leafcutter ants can strip as much as 17% of the leaf biomass from plants in their ecosystem and can clear entire trees in under a day. Next to ours, leafcutter ant society is the most complex society on earth. They build nests that can contain thousands of rooms and cover up to 0.5 km2, a feat that is necessary since a mature colony can contain more than eight million individuals.

But if they’re not eating the leaves that they carry home, what are they doing with them?

Farming. Leafcutter ants use leaves as their fertilizer to grow their crop: fungus.

They cultivate their fungal gardens by providing them with freshly cut leaves, protecting them from pests and molds, and clearing them of decayed material and garbage. In return, the fungus acts as a food source for the ants’ larvae. The ants are so sensitive to the fungi’s needs that they can detect how they are responding to a certain food source and change accordingly. This symbiotic relationship also benefits from a bacterium that grows on the ants’ bodies and secretes antimicrobials, which the ants use to protect their fungi.

Adult ants don’t feed on the fungus, but rather get their nutrients from leaf sap. Smaller adults often hitchhike on leaves being carried back to the nest to opportunistically feed on the sap, as well as protect the carrier from flies and to check that the leaf isn’t contaminated with other fungi.

Leafcutter ant society is divided into castes, with each group having a different role to play. The largest ants, called Majors, act as soldiers and heavy lifters. They guard the nest and help to clear out the highways between the nest and a food source. The next smallest caste, the Mediae, is made up of generalists, cutting and transporting the bulk of the leaves for their colony. Next in size are the Minors, who protect the foraging path and food source, and the smallest ants, the Minims, work exclusively at home, tending to the larvae and fungus garden.

Some Minims work exclusively as garbage collectors, removing decaying organic matter from their fungal gardens and transporting it to dedicated garbage rooms placed well below the rest of the nest. After becoming garbage collectors, these ants will never interact with the fungus or the queen, to prevent any disease from being passed onto them.

Leafcutter ants are often presented as a single species of ant, but in reality, there are 250 species of ants which practice fungus farming. Besides their agrarian tendencies, these ants have something else in common: queens. When it comes time to establish a new colony, winged virgin queens-to-be take part in their nuptial flight and mate with many different males to collect sperm. They then set out to find an appropriate place for a new colony, bringing with them a piece of the fungus to seed their new fungal gardens.

Do Fish Drink?

2 minute read
Originally published here: https://mcgill.ca/oss/article/you-asked/do-fish-drink

Our bodies and fishes’ (yes, fishes is a grammatically correct plural form of fish) bodies as well need water. Without it, the chemical reactions that take place constantly in our bodies would have no solvent and we would die.

Nonetheless, it seems silly that an underwater creature should have to drink. Can’t they just, I don’t know, absorb it or something?

Kind of.

Fish do absorb water through their skin and gills in a process called osmosis. Osmosis is the flow of water across membranes from areas of low concentration of dissolved things (solutes) to areas of high concentration. It serves to equalize the concentrations in the two areas.

In the case of freshwater fish, their blood and bodily fluids are much saltier than the water they swim in, so water will flow in through their gills. The opposite is true for saltwater fish.

As well as getting water through osmosis, saltwater fish need to purposefully drink water in order to get enough into their systems. Where their freshwater counterparts direct all of the water that comes into their mouths out through their gills, saltwater fish direct some into their digestive tract.

But fishes’ bodies, just like ours, need a certain concentration of salt to function best. They can’t just allow the water to diffuse freely through their gills; the saltwater fish would shrivel up and the freshwater fish would explode!

To stop the exploding fish phenomenon, their gills have special cells that selectively pump salt in, or out of their blood. In freshwater fish, the cells constantly pump salt in, and in saltwater fish, they constantly pump salt out. Saltwater fishes’ kidneys also help to filter out some of their salt.

Want to see osmosis for yourself? Submerge some potato slices in salt or fresh water overnight. The saltwater-soaked ones will still be crunchy, but the freshwater ones, having absorbed water, will be softer.

In short: some, but not all, fish drink. Kind of like how some, but not all, fish… fart.

So, keep in mind that next time you’re preparing your fishes’ tank you’re not only creating his environment but his beverages too.

Are Goats the Secret Tool We’ve Been Looking for to Prevent Wildfires?

2 minute read
Image made by Ada McVean
Originally posted here: https://mcgill.ca/oss/article/did-you-know-environment/goats-might-be-secret-tool-weve-been-looking-prevent-wildfires

Goats are really useful creatures. We use their milk, fur, meat and… firefighting skills?

In several places goats and sheep are being herded into fire-prone areas. The hungry herbivores move through the land, munching on shrubs, trees and grass, and creating firebreaks. Since goats only stand about 1 metre tall, they will graze heavily on low-lying plants, creating a gap between the ground and higher trees. This gap can prevent fires from spreading or slow them down. Some places in Spain have even blamed recent wildfire severity on the declining number of herds grazing on the land.

Goats are perfect for the job for a few reasons. Unlike some grazers, goats do not limit themselves to leaves or grass, eating the wood and bark of smaller plants as well. Goats are able to traverse a wide variety of terrains, and they are naturally resistant to several toxic plants. They can also be herded in tandem with sheep or cows, creating an even more effective grazing party. Using goats comes with the added advantage of reducing the carbon footprint, compared to clearing brush with machines, and improving air quality. The waste left by goats is simply absorbed into the ecosystem of the area.

Studies have shown that a herd of 250 sheep can reduce the available plant mass by 75% in 30 days. When a wildfire in Utah with 15-foot-high flames reached an area that had been cleared by goats, the flames dropped to only 3 feet tall in lightly-grazed areas and stopped entirely in more heavily-grazed ones.

The biggest barrier to using goats in this way is a lack of trained and skilled herders and herding dogs to manage the goats. So, if you’re looking for a career change, a position in goat herding is probably available. Given goats’ relative quietness and lack of air-polluting outputs, they could be especially useful for grooming areas near residences and towns, so you may not even have to commute very far.

Little Dogs Raise Their Legs High to Pee, Thinking It Makes Them Look Tough

1 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know/little-dogs-are-trying-look-tough-when-they-raise-their-leg-really-high-pee

Female dogs opt for less yoga-like squatting postures than their male companions, who can sometimes be seen with their leg so far in the air they seem about ready to topple over. It turns out that the height to which male dogs raise their leg has a lot to do with their body size, where they are, and who’s around.

All canines use urine to mark their territory, but some do it more than others. All male dogs, big and small, raise their leg to pee or scent-mark much more frequently in the fall than in the summer, likely because it is mating season. Accordingly, the frequency of their urination increases whenever there is a female dog or a male competitor present. Males will sometimes even raise their leg when their bladders are empty, performing what is called a raised-leg display. Females mark their scent much more often when near their nest or den, and males mark theirs more frequently on unfamiliar objects and places.

The height to which they raise their leg also seems to have to do with getting a mate, defending territory, or intimidating other males. Male dogs raised their legs higher when near the edges of their territories, or when they were with their mates. But proportionally, littler dogs raised their leg much higher than their big friends. Perhaps this is their way of making themselves seem larger, like a bettawith its fins or a cat with its fur.

All we know for sure is that they look pretty silly to us.

Dragonflies Experience as Much G-Force as Fighter Pilots

1 minute read
Originally posted here: https://mcgill.ca/oss/article/did-you-know/dragonflies-experience-much-g-force-fighter-pilots

Gravity and the human body have a finicky relationship. Too little gravity and humanslose bone density, experience extreme nausea and become anemic. Too much gravity and humans lose consciousness and die. So how do people who experience hypergravity on a regular basis deal?

Astronauts experience microgravity while on the moon, but also hypergravity (up to 3.2 g) during take off. It’s their Earth-based friends though, fighter pilots, that experience the highest gravitational forces, up to 9 g.

Most people would pass out with 5 g (that’s why most roller coasters don’t exceed 3 g), but fighter pilots wear compression suits to counteract the forces and practice contracting their lower abdominal muscles. These serve to force the blood out of their legs and into their brain, preventing the loss of consciousness.

If a pilot descends too quickly they can experience negative g-forces. The human body is even less tolerant of these, with what’s called a redout, too much blood in the head, occurring with only -2 g.

Some animals are really good at dealing with hypergravity though. When flying in a straight line, dragonflies can accelerate with up to g of force. When they turn corners, this increases to 9 g. And they don’t even need to wear a flight suit.

The Impossible Burger: A Vegetarian Breakthrough Brought to You by Science

5 minute read
Originally posted here: https://mcgill.ca/oss/article/nutrition-environment-general-science/impossible-burger-vegetarian-breakthrough-brought-you-science

I’ve been eating veggie burgers for a long time. If it’s sold in Canadian grocery stores or fast food restaurants, there’s a good chance I’ve tried it. There are some I like more, and some I like less, but they all fall into one of two categories: fake meat and veggie.

I like a veggie burger that knows it’s made of veggies, not one that’s pretending it’s beef. Mostly because all fake meat patties seem to come out as bad imitations. But, that seems to be changing in a big way.

The Impossible Burger, made by Impossible Foods, is a plant-based burger designed to fry, bleed, taste and smell just like beef. Incredulous? So was I.

What makes this burger different? The same thing that makes Fireball taste so good and Buckleys taste so bad. Chemistry!

The molecule responsible for the “meaty” taste of meat is heme and it’s found in animal muscle cells in the protein myoglobin. Sadly, there are no non-animal sources of myoglobin, but there is something pretty close: leghemoglobin.

Leghemoglobin is found in the roots of legumes and can provide a “meaty” taste very similar to its animal-based brother. It’s not especially environmentally friendly or affordable to dig up bean plants for their roots, so Impossible Foods had to get creative. They genetically engineered yeast to make leghemoglobin, so that by growing the yeast in fermentation vats they were able to create all the heme needed to make a meaty tasting veggie burger.

Other than heme, the ingredients of an Impossible burger are pretty similar to any other fake meat product. Wheat and potato protein, coconut and soy oil, some binders. All perfectly safe (despitesome cries of outrageover soy and GMOs).

How does it taste? On a recent trip to New York I went out of my way to find one and was not disappointed. The texture isn’t perfectly meat-like (or at least how I remember the texture of meat) but the taste was very similar, as was the look. But don’t just take my vegetarian opinion on the matter, here’s what Michael Marshall, The Project Director of the Good Thinking Society, had to say on it:

“If I hadn’t known what the Impossible Burger was – and, more to the point, what it wasn’t – I’m not sure I’d have been able to tell. It definitely wasn’t the best burger I’ve ever had, but it also wasn’t the worst, and that’s pretty impressive given that the rest of them (at least, I hope the rest of them) had the head start of actually being a burger. Possibly the most remarkable thing about the Impossible Burger is that they’ve managed to make a meat-substitute that differs from meat so little as to be unremarkable. If you’re looking to reduce or cut out meat but fear you’ll miss the experience of eating meat, it’s a pretty solid substitute.”

Sadly, the Impossible burger still isn’t available in Canada. A rival product however is being pushed by A&W: The Beyond Meat Burger.

This meat alternative also makes claimsabout tasting, smelling and having a meat-like texture. However, as far as I can tell it contains similar ingredients to any other veggie burger, with some beet added to dye the uncooked patty red. A&W’s website proudly states (several times) that their product is GMO free, a big change from Impossible Food’s pride in their GM technology.

Never one to pass up a veggie burger, I obviously went and tried the Beyond Meat Burger too. I was, to put it nicely, underwhelmed. It didn’t taste like meat. It didn’t really taste like anything other than a typical cheap veggie patty, and I honestly think I preferred A&W’s old veggie burger. It was boring enough that I’ll probably just opt for some French fries next time we make a road trip stop at an A&W.

But it’s not all about taste, right? Maybe the Impossible burger is delicious but very unhealthy? Well, nutrition-wise the two new veggie burgers actually beat out their meat competitors in terms of protein and iron (two of the nutrients vegetarians often struggle to consume). The Beyond Meat Burger has a lot more fat than the Impossible burger, but is still on par with the meat burgers. Perhaps the biggest lesson to learn from comparing the burgers is that while veggie burgers tend to cost the same (or less) as meat ones, at least at A&W they’re much larger!

NutritionImpossible
Burger
(85 g)
Beyond
Meat
Burger
(113 g)
No Name beef
burgers
(113 g)
A&W
hamburger
(58 g)
Calories220270320150
Fat (g)13202712
Saturated fat (g)105135
Sodium (mg)43038043045
Sugar (g)1010
Protein (g)20201411
Iron (%)1525156

Even if you’re not passionate about finding the perfect veggie patty like I am, there are good reasons to care about the evolution of vegetarian meat alternatives.

The meat industry is one of the largest contributors to greenhouse gas emissions. Animals raised for meat expel 37% of all human-released methane. They also require enormous amounts of water. 1 ton (907 kg) of beef takes 16.7 million litres of water to produce, which is more than six times the 2.52 million litres required for a ton of soy.

Infographic made by Ada Mcvean

There is also the animal welfare aspect of the meat industry to consider, as well as the documented health benefits to minimizing your meat intake. Technologies like lab grown meat or ethically raised animals can help your conscience, but not your wallet or heart. Part of what makes meat-like alternatives so compelling is their affordability.

While there are issues with replacing all meat with vegetable proteins, such as plant sources lacking some nutrients and ethical issues of putting herders out of work, there is a lot to be gained by embracing a vegetarian diet (or just going veggie sometimes). The Impossible Burger, and other products I hope are available shortly, might be a simple way to do that.

Until then, I guess I’ll stick to grilling Portobello mushrooms. Not such an impossible task.