Power to the Parasites… Power to the Parasites, Right On (Right On!) It’s a Chelsea L. Wood Interview

This happens every year. Every single year. November rolls around. I feel pretty good about the bulk of the books that I was able to read throughout the year. And then, at the very last second, I encounter some kind of marvelous nonfiction book for older readers. And a lot of the time (I have no idea why this is the case) it is simultaneously fascinating and gross.

How are we feeling about parasites today?

Power to the Parasites (which, let it be said, is a title so good that I hope someone somewhere got a medal for it) is out as of right now with Laura Godwin Books and can be best described this way:

Power to the Parasites! lets you in on a secret: Parasites are all around you, all the time, quietly running the world. You might think of them as slimy, disgusting freeloaders – tapeworms and roundworms and ticks and lice, too small to be important and too selfish to be valued. But by the end of this book, you’ll realize that sometimes parasites are the good guys.

Learn where you’re most likely to find parasites in your own food (heads up, you might not want to eat any uncooked fish right before reading this book), and how parasitic infection changes the behavior of many organisms—including human beings.

Parasites might be weird and mysterious, but the better we understand them, the less we have to fear about them. In fact, many parasites are in big trouble. With climate change threatening parasites around the world, there’s no better time than right now to learn about these often-unseen creatures living among us.

They asked, “Hey, Betsy. Do you want to interview parasitologist and professor Chelsea Wood about her book?” which I heard as, “Betsy, you like gross stuff for kids, so do you want to tackle this one?”

Yes, folks. Yes I did. Because it’s just so doggone cool:

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Betsy Bird: Chelsea! Thank you so much for talking with me today. And congrats on the publication of POWER TO THE PARASITES! (marvelous title, for the record). This is, to my understanding, your first children’s book. Parasites are a part of your day-to-day professional life already. What made you inclined to write a book about them for kids?

Chelsea L. Wood: The book has a curious origin story! I love talking with people about parasites, but until a few years ago I thought only adults wanted to hear about them. Then I was invited to be a guest on an NPR podcast. Laura Godwin, of Godwin Books, heard the interview on the radio and was charmed; she thought my parasite stories would make for a great children’s book. I was skeptical at first, as learning about parasites necessitates hearing a lot about blood, guts, death, and poop. But it turns out that kids love that stuff! I’m so glad to have a new audience to blab about parasites with.

BB: For those that have a knee-jerk reaction to even the word “parasite”, can you sell us on them? Why are they so interesting and why should kids learn more than a few facts about them?

Chelsea: Whether we’re grossed out by them or not, parasites are all around us, all the time. They tend to be hidden inside their hosts, so they are quite easy to overlook, even for professional biologists! But there is almost certainly a parasite within a few feet of you right this very second, no matter where you are. Given the fact that we share our lives with a whole menagerie of parasites, it probably behooves us to know a thing or two about them.

But over and above the naked self-interest of learning how to recognize and avoid parasites in our day-to-day lives, you really are depriving yourself of one of nature’s greatest shows if you don’t learn about parasites. They are just so otherworldly, so breathtaking, so unlike any other creatures on Earth! You’ve only got to get down on their level – to look at them under the microscope – to appreciate how beautiful they are. Here are a few I’ve encountered:

• A trypanorynch tapeworm has no eyes, mouth, or face, but instead a head with four ejectable tentacles, each armed with thousands of recurved spines – perfect for clinging to the slippery intestinal wall of a shark. When it needs to avoid being swept out with the tide of poop flowing down the gut and into the outside world, the worm simply lays its tentacles down on the gut wall, digs in its spines, and retracts the tentacles, securely anchoring itself in place.
• That scourge of hikers and dog owners, Giardia, is gorgeous under the microscope, with long, resplendent flagella trailing behind like a bird’s tailfeathers.
• Parasitoid jewel wasps are appropriately named – they resemble nothing less than winged gems.
• If you want to see for yourself, you can check out these videos that I’ve made over the years:
  • Tapeworm larva emerging to become an adult worm (dissected from a coral reef fish on Kiritimati Island in the central equatorial Pacific): https://www.flickr.com/photos/chelsealwood/4734143095/in/album-72157624358713600
  • Several parasites from the central equatorial Pacific (dissected from wahoo, snails, and tuna): https://www.youtube.com/watch?v=d3wced1DQd4
  • Human head louse (collected from my PhD advisor’s son): https://www.youtube.com/watch?v=EJ8EfRORTGo
  • The isopod parasite Portunion conformis (dissected from a shore crab collected in Tacoma, WA): https://www.youtube.com/watch?v=Z7SkWWHhYxA

In short: because they are so unfamiliar, learning about parasites for the first time is like learning the natural history of an alien planet – except even weirder, because that planet is ours.

BB: I’m not gonna lie. I started with the tapeworm video, thinking I’d stop there and then just watched all of them. But the music on the tapeworm one? *chef’s kiss* Now we think of parasites in all kinds of ways, but we rarely think about them in terms of climate change. Not to spoil your book or anything, but what does climate change even have to do with the current parasite population?

Chelsea: As the climate changes, ecosystems change. We already recognize that this has effects on many kinds of animals – some species thrive in these altered environments, but some diminish, even to extinction. The same is true for parasites. Climate change will increase the abundance of some parasites – for example, 2015’s Zika virus outbreak was pretty clearly tied to climate change. Zika popped up in 31 countries because rising temperatures increased the abundance of mosquitoes, which transmit the Zika virus from person to person. But there will also be some parasite species that decline as global temperatures warm up, even to extinction. By one estimate, 30% of parasitic worms will be extinct by the year 2070 due to climate change.

“Who cares?” you might think to yourself. “Good riddance.” Maybe. But maybe not. There are many parasite species that live out in nature and actually do really good things for their ecosystems – like keeping a cap on the abundance of hosts that otherwise might become overabundant pests, or helping predators find meals. We might miss them when they’re gone.

BB: Considering how many facts you’re dropping in this interview alone, were there any facts you absolutely 100% had to get into the book? And were there any facts that you initially really wanted to include and then were unable to?

Chelsea: There is one parasite that I have a real soft spot for: Amphilina foliacea. “Amphie” is a tapeworm that you can find today in sturgeon. Scientists think it used to parasitize marine reptiles like mosasaurs during the Cretaceous period, when dinosaurs ruled the Earth. When the meteor that killed the dinosaurs struck, mosasaurs were also wiped out, and probably many of their parasites went extinct, too. But Amphie found a way to keep going, by shortening up its life cycle, leaving out the mosasaur host and reproducing in sturgeon. It is a scrappy, never-say-die survivor. I think about it when I face challenges of my own: “If Amphie can survive a global catastrophe that killed off 75% of all species living on Earth, I can survive this!”

In every year I’ve taught my undergraduate Parasite Ecology course, the lecture on Toxoplasma gondii has been a consistent hit, so I knew that parasite also needed to appear in the book. Why are people so interested in “Toxo”? Probably because it infects about a third of the humans living on Earth today. Most people don’t know that they are infected, but that doesn’t mean that the parasite is benign. It quietly pulls the strings of human behavior, making small tweaks to the personality of its host. Infected people are three times more likely to get into car accidents. They tend to take more risks. Infected men will become suspicious, jealous rule-breakers. Infected women tend to become more warm-hearted and gregarious. It’s very strange to think that something as personal as your own personality could be shaped, even created, by a tiny-single-celled stowaway.

There are tens of thousands of parasite species in the world, and probably just as many stories to tell. I wasn’t able to squeeze in a chapter about Ribeiroia ondatrae, the trematode parasite that causes its frog hosts to grow extra legs, or about Gyrodactylus, the monogenean parasite that reproduces like a Russian nesting doll: a mother worm can be pregnant with a pregnant daughter, who is pregnant with her own pregnant daughter. Power to the Parasites! is just an introduction. There are still many, many more weird and wild parasite stories to tell.

BB: Honestly, I could hear you talk about them all day. Often when one writes a book you don’t imagine how it might look visually. You were paired with the art of Dave Mottram. How do you feel about the final product?

Chelsea: I was shown Dave’s artwork early in the production process and I knew immediately that he was the person for the job. He is really good at nailing biological details while still managing to imbue the characters he draws with personality. I knew we would need that to depict the parasites – they are weird and mostly unfamiliar creatures, but I wanted the artwork to inspire sympathy, empathy, and connection between the reader and the parasites presented. Dave’s final illustrations exceeded even my extremely high expectations.

BB: Final, and very difficult, question: What is your favorite parasite fact? You can choose only one.

Chelsea: At least 40% of animal species on the planet are parasites. Let that sink in for a moment. Almost half of all animal species are parasites, and yet it’s possible to get a degree in biology without ever once hearing a peep about them! People are often shocked by this fact – and I think that reveals something really important about parasites: they are ubiquitous, but ignored. When you learn a little bit about them, it’s like getting to see into an alternate dimension of reality – an underworld, an upside-down, a place that is usually invisible but humming away under the surface of everything that we find familiar. Getting to step into that world is intoxicating – and some of us never turn back!

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Here’s hoping a book like Power to the Parasites infects our young with a desire to learn more about the natural world. I’d like to thank Chelsea for taking so much time, energy and attention to answer my questions today. Seriously, I interview people all the time, but she put some seriously amusing (and horrifying) facts in here that make me want to reread this book of hers again! Thanks too to Morgan Rath and the team at Macmillan Children’s Publishing Group for helping to put all this together. Power to the Parasites is out right now. Go gross out/entrance a kid with it today.

Filed under: Best Books, Best Books of 2024, Interviews