Science + Activism

by Megan Clendenan

Here in Canada, we’re nearing the end of summer, but there’s still time to take advantage of the still-hot weather. One thing I love to do is go swimming – whether it’s in the ocean, a lake or a river, there’s nothing like jumping in (usually quite cold!) water to cool off and feel like it’s vacation time.

When you head out for a nice swim on a hot day, the last thing you want is to be floating through a sea of fecal bacteria. But sometimes that’s what happens….

When Stella Bowles was 11, she began to ask questions about why she wasn’t allowed to swim in her local river in Nova Scotia. She learned it was because of straight pipes, a sewage-disposal system that flushed waste from toilets directly into the LaHave River. Even though they were illegal, there were 600 straight pipes emptying raw sewage into the river. Stella was upset by the straight pipes and wanted to know how polluted the river was because of all the fecal contamination. She decided to do her grade 6 science project on the topic. After reaching out to a local conservation non-profit, Stella found a mentor who helped her take samples of river water and test for bacteria.

Artwork by Julie McLaughlin, from pg. 84-85 of Fresh Air, Clean Water: Our Right to a Healthy Environment

 

She found contamination levels well above Canadian standards for swimming and boating. She decided she had to share her findings, as the river was a health hazard. With the help of her mom, she started a Facebook page and spread the word. She also put up a big sign by the river that said “This River is Contaminated with Fecal Bacteria.” Stella’s efforts got people’s attention, including the Canadian government. More than two years later, in 2017, the government finally announced that it would spend $15.7 million to clean up the LaHave River.

Science + activism can help create change! Citizen scientists who warn of danger and continue to speak up, as did Stella, can have important positive results for both human and environmental health.

Want to learn about more young scientists creating change? I had the opportunity to interview Stella as well as a number of other exceptional youth activists, scientists and artists for my book FRESH AIR, CLEAN WATER: OUR RIGHT TO A HEALTHY ENVIRONMENT. And Stella is herself an author – check out her book in the resource list below.

Sources/Resources

Bowles, Stella, with Anne Laurel Carter. My River: Cleaning up the LaHave River. Halifax, NS: Formac Publishing, 2018.

https://www.cbc.ca/news/canada/nova-scotia/stella-bowles-lahave-river-clean-up-funding-1.4184663

Why Do We Crave Junk Food?

 by Anne Munier

Evolution influences human behaviour by holding on to traits that make us more likely to survive and have babies. Behaviours like avoiding vicious predators, jerking your hand away if you touch something hot, or cooperating with community members all helped our ancestors survive, and have been passed down through generations. Traits that lead to very *unhealthy* outcomes (like, say, having an irresistible urge to play with vicious predators) tend to get weeded out of the population, because kids who play with tigers generally don’t survive long enough to pass on their genes.

So why do so many of us feel compelled to overeat junk food? Junk food, for the sake of this article, means processed foods that are high in sugar, fat, and salt. This type of diet is harmful for our health, yet it is a rare person who craves steamed broccoli over milkshakes, pizza, or brownies.

Oddly enough, these cravings are very much shaped by human, and even pre-human, evolution.

A monkey with a sweet tooth munching on jackfruit

Millions of years ago, some early primates developed a taste for fruit, even though it tends to grow high up in trees, and it’s much easier to munch on plants that are close by. These particular primates did awfully well because fruit has much more energy (i.e. calories) than other foods, and is easier to digest. This leads to healthy primates in good condition to have lots of babies. These babies inherited their parents’ love of fruit, and likewise did better than their counterparts who couldn’t be bothered to climb for their food. And so it continued through the generations, until eventually the whole species were driven to eat as much fruit as possible.

(Fun Fact #1: Primate species that eat the most fruit have the biggest brains.)

Moving along our evolutionary story, early humans were developing ever-larger brains, which, along with our active hunter-forager lifestyles, meant we needed a ton of energy to keep going. We continued to love sugar from fruit or wild honey when we could get it (which wasn’t often), as well as high-fat foods, which are also high in calories. When we had the chance to eat more than we needed, our bodies stored the surplus as fat, allowing people to have more babies, and enhancing survival during times of food scarcity.

(Fun Fact #2: Humans tend to be better at storing fat than other animals. Even super-skinny humans have more body fat than the chunkiest chimpanzee).

Fast forward to the 21^st century -- most of us live in relative prosperity and have constant access to junk food. And while treats that our hunter-gatherer ancestors enjoyed came wrapped up with fiber, vitamins and minerals, today’s treats -- not so much.

We are now hard-wired to seek out sugar and fat, to the point that they stimulate pleasure centres in our brain. This is true for newborns and adults, across all cultures in the world. Healthy food elicits a bit of this pleasure stimulation, junk food elicits A LOT more. And the more junk food we eat, the more we develop a tolerance to it, so we need to eat more to get that same pleasure response. Sound familiar? Addictive substances, including cigarettes and drugs like cocaine, work on our brain in the same way.

Melt-in-your-mouth Cheetos have a very profitable mouth feel.

Then there are the manufacturers of processed junk foods. They want to maximize their profit by selling as much product as they can. And they have all sorts of tricks up their sleeves about how to get us (and keep us!) hooked on the stuff. For example, they figure out a food’s:

• Bliss point: the perfect ratio of sugar, fat, and salt to maximize deliciousness and over-consumption

• Mouth feel: how food interacts with your mouth -- the more quickly it melts, for example, the more it confuses our brain into thinking that we’ve consumed fewer calories than we really have

What is the result of these biological forces on one hand, and the commercial forces on the other?

The number of people who are obese is growing annually, as are associated conditions such as high blood pressure, heart disease, chronic inflammation, and Type 2 diabetes. Add to this the impacts on mental, psychological and dental health, and ballooning health care costs that affect everyone.

So, given enough time, could humans evolve to lose a taste for junk food, since it’s so damaging? Maybe, but let’s not hold our breath. Evolution acts genetically, by passing on genes to our children. But most disease related to excessive junk food affect people later in life, after they’ve already had (or not had) kids.

Is it inevitable then, that we’ll continue to eat excessive amounts of junk food, and our health will keep deteriorating? Not at all! Here are two things to keep in mind as we go forth in our junk food-laden society:

1. Evolution has also endowed us with big beautiful brains capable of critical thought. Even if things are stacked against us, we can make great (if sometimes tough) decisions about our eating and exercise habits.

2. We need to recognize that diet goes beyond will power. Our biology and powerful market forces are designed to make us crave junk food, which, sadly, is often cheaper than whole food. So let’s NOT blame anybody for “lifestyle diseases” caused by too much junk food. Rather let’s consider societal changes that could improve things -- like limiting marketing of junk food to children, or ensuring that healthy food is easily available to all of us. What ideas do you have?

It’s tough to be tiny—or is it??

by Kim Woolcock

Growing up, I was always the shortest person in my class. I was guaranteed to lose games of Keep Away. I could never reach the top shelf. And the basketball hoop seemed to be infinitely farther away from me than from other kids (OK, maybe there were other factors in my lack of baskets scored). But in sixth grade, my very tall friend gave me a sweatshirt that said, in glittery letters, Tiny but Tough, and that became my motto. So when my publisher sent me an image of a tardigrade (the poster children for Tiny but Tough):

Hypsibius dujardini

Taken by: Willow Gabriel, Goldstein Lab http://tardigrades.bio.unc.edu/

and asked what I thought about doing a book on minibeasts, I jumped at the chance. I decided right away that it would be about not just minibeasts, but the superpowers of minibeasts. Because there are plenty of upsides to being tiny.

I read a giant stack of science papers while researching this book, and I learned about SO many fascinating creatures. One of my favourites is the water scavenger beetle (Regimbartia attenuata). These guys are just round black dots, a few millimeters long. They look completely unassuming. They don’t have any obvious defenses, and if a frog tries to eat them, well, it succeeds. They get swallowed. <gulp!>

But!

That is not the end of the story. Because after being swallowed, these beetles walk right out. That’s right—they get swallowed, and they don’t care. A few minutes to a few hours later, the beetles emerge ALIVE from the frog’s butt. It’s not clear whether the beetles hike out through the frog’s intestines, or whether they tickle the frog’s innards, maybe by wiggling their legs, encouraging it to send them speedily on their way.* Either way, these otherwise inconspicuous creatures are escape artists par excellence.

Along the way I learned that larvae of the horse mint tortoise beetle (Physonata unipunctata) defend themselves by carrying a poop umbrella with their butt. That Asian jewel beetles (Sternocera aequisignata) camouflage themselves with glitter. That the walnut-sized bobtail squid keeps glowing bacteria in its belly, to disguise itself as a moonbeam while it feeds in the nighttime ocean. And that because ogre-faced spiders listen with their legs, they can catch prey while blindfolded (and yes, scientists make tiny blindfolds for spiders).

If you’d like to learn more about the amazing world of minibeasts, check out my book It’s Tough to be Tiny:The Secret Life of Small Creatures, illustrated by Stacey Thomas (Flying Eye Books, 2022). It’s all about the superpowers of small creatures, from springtails to cone snails, and how they stay safe, hunt for their lunch, or buddy up with bigger creatures for the benefit of both. It’s full of glitter and gross, because nature is both.

I’d like to know, which superpower would YOU choose?

* Wax-coated beetles didn’t make it out.

Resources:

K Kjernsmo, HM Whitney, NE Scott-Samuel, H Knowles, L Talas, and IC Cuthill. (2020) Iridescence as camouflage. Current Biology 30 (3): 551–555. https://doi.org/10.1016/j.cub.2019.12.013

M McFall-Ngai. (2008) Hawaiian bobtail squid. Current Biology 18(22):PR1-43-1044. https://doi.org/10.1016/j.cub.2008.08.059

JA Stafstrom, Hebets EA. (2016) Nocturnal foraging enhanced by enlarged secondary eyes in a net-casting spider. Biology Letters 12: 20160152. http://dx.doi.org/10.1098/rsbl.2016.0152

JA Stafstrom, G Menda, EI Nitzany, EA Hebets, and RR Hoy. (2020) Ogre-faced, net-casting spiders use auditory cues to detect airborne prey. Current Biology 30(24): P5033–5039.

S Sugiura. (2020) Active escape of prey from predator vent via the digestive tract. Current Biology. 30 (15): PR867–R868.

https://www.dailycamera.com/2010/07/22/jeff-mitton-tortoise-beetles-and-fecal-shields/