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Introduction

Symbiosis. Many would say this word describes two living things that benefit each other. While this is a common understanding of the term, in biology, symbiosis has a slightly more broad definition. Symbiosis (as defined by Western science), is an intimate association between two or more organisms, typically a very specialized association that has evolved over millions of years. For example, many people are familiar with the mutually beneficial association between clownfish and anemones. However, there also exists a clownfish parasite that eats the fish’s tongue and mooches off its food. This too is symbiosis; there must be a close relationship, but not everyone necessarily benefits.

SymbiosisThere are 3 main types of symbiosis. Categorizing a relationship into these 3 types depends on who gets something out of the deal.

  • (+/+) mutualism (what most people think of when they hear symbiosis)
  • (+/o) commensalism
  • (+/-) parasitism

The plus (+), minus (-), and zero (o) symbols represent the impact on each of the organisms involved. A plus means that the organism benefits from the relationship, a minus means they are negatively affected by it, and a zero means they are not significantly affected by it either way.

You may have noticed that there are more possible combinations of pluses, minuses, and zeros not listed above. Below are the rest of them, though these are debated as to whether they are truly forms of symbiosis or not. This is because they are too broad or unspecific; just because a seagull may benefit from eating your french fries does not mean they have a close evolutionary relationship with potatoes.

(+/-) predation/herbivor
(-/o) amensalism
(-/-) competition
(o/o) neutralism

When I first heard about symbiosis in school, I was ecstatic. Not only was I learning about amazing coadaptations, but every symbiotic relationship could be satisfyingly placed into one of those neat little categories, or so I thought. It turned out that the more I learned, the more I researched in the lab, and the more I talked to other scientists, the messier these categorizations became (we will explore some of these “exceptions to the rule” in the lesson below). These counterexamples were important because I realized something that to me was quite profound, and something that I think we should teach every student: your textbook is lying to you. 

Textbooks and other learning tools can be helpful, but they are also biased and simplified. As an educator, I want my students to learn earlier than I did that biology is messy and breaks the rules. Below are a couple activities you can use to guide students through this concept, best for students who have already been introduced to the idea of symbiosis.

Activity 1

Symbiosis is a great topic for a card sorting activity (you can find an example at https://learn.islandwood.org/ab-sorting/).

  • Make cards with different symbiotic relationships (examples below), along with some context regarding the nature of the relationship with text and/or pictures. Students may also brainstorm ideas and create the cards themselves. Some examples can be classic or “easy” relationships to sort, others can be a bit trickier or in some of the “contested” categories of symbiosis. Students will sort the cards into the 3 main categories of symbiosis (mutualism, commensalism, parasitism). This is best done in groups to facilitate discussion, but students can also complete their sorts individually and then compare afterwards.

Below are some classic examples to get started:

  • Epiphytes on trees (o/+)
  • Barnacles and whales (+/o)
  • Clownfish and anemones (+/+)
  • Bees and flowers (+/+)
  • Lichen/algae and fungus (+/+)
  • Wasps and caterpillars (+/-)
  • Dogs and fleas (+/-)

These are some much more contested relationships that will be explored in the next activity:

  • Water buffalo and oxpeckers (?)
  • Tapeworms and humans (?)
  • Leaf cutter ants (?)
  • Bacteria and humans (?)

Hopefully, the card sort will spark active discussion. There may be disagreement as to how things should be categorized, and that’s great, because it means students will have to dig deeper into their reasoning. During and after the sort, ask students to justify how they sorted their cards, and ask students with different answers to figure out why they disagree. Then, you can open it up to a large group discussion with the next activity to further challenge student thinking.

Activity 2

The following are case studies of classic symbiotic relationships that are more complicated than they may first appear. Each case includes 1) theme or lesson to discuss, 2) the example relationship, and 4) an explanation of the nuance behind why it is a contested example. You might have students re-sort their cards from activity 1 after they have discussed these case studies.

OxpeckerTheme 1: Categorization is subjective and depends on the observer

Example: Oxpecker and Bison. A supposed poster child of mutualism, the oxpecker bird receives nutrition by eating insects and other pests off of the skin of bison, giving it some relief and health benefits.

Nuance: Scientists have found that the oxpeckers are in fact not eating parasites, but instead picking at the bison's wounds and drinking their blood, perhaps making the birds a parasite themselves. (P.S. the same goes for remoras and sharks; watch a video about this at https://youtu.be/yzDWWzDenZQ)

 

tapeworm adTheme 2: Defining the nature of symbiotic relationships means defining values of good and bad

Example: Tapeworms. These are a well known parasite that live in the intestines of vertebrates such as ourselves, where they absorb food through their skin and deprive the host of nutrients.

Nuance: Tapeworms were used in the early 1900s as a weight loss treatment. While this practice is no longer recommended for a number of reasons, tapeworms were at one point seen as a helpful remedy--a mutualistic companion. Nothing about their nature changed, it was simply our perception of them that shifted. This really highlights the impact of societal norms on the perception of the natural world. Weight loss can be a sensitive subject for some people, so be sure that you present this example with care and compassion, and do not use it if you know any of your students would be uncomfortable. The use of leeches for medical purposes is a similar example that can be used as a substitute to illustrate the same point.

Theme 3: Symbiosis is not always simple partnership between two organisms

Example: Leaf cutter ants. Also known as attine ants, these insects cut leaves off of plants and bring them back to their colony. Without further observation, this may appear to be a simple case of herbivory, one of the contested cases of symbiosis listed at the top of this article.

Nuance: This example of symbiosis actually involves at least 6 different organisms, as diagrammed below—and this doesn’t even include the plants the ants eat! A red arrow on the diagram represents a negative or parasitic relationship, and a green arrow represents a positive or mutualistic one.

Symbiosis2

Diagram by Michael Poulsen

Extension

Microbes are great at breaking the rules. There are many surprising examples of bacteria switching between mutualism and parasitism with their hosts, or acting as both a parasite and a partner at the same time. This (https://courses.lumenlearning.com/boundless-microbiology/chapter/microbial-symbioses/) is a great resource to get started, but I highly recommend further exploring the world of symbiotic microbes with your students!

Conclusion 

Categories can be useful--they make complicated concepts more simple, universal, and easier to understand--but there are often exceptions. In biology, the exceptions are sometimes the most interesting things to study. Really, every example of symbiosis could be more carefully examined. Is one organism both a benefit and a detriment to another? If it’s mutualism, does one organism benefit more? What environmental factors might change the nature of this relationship? How did this relationship evolve and how might it continue to change?

This uncertainty is not proof that science is broken, it’s proof that science works. To me, science is about continuing to learn, and it cannot be successful unless it is routinely questioned, retried, and modified. When a discovery breaks the scientific norm, it should be a moment of triumph and growth for the field. When this happens, it is also a chance for us to question our own assumptions and biases. It is critical that educators challenge the idea that relationships are defined and finite no matter the discipline. We will always have something to learn from the natural world, and we should always be thinking about how we can better understand and protect it. Now that is symbiosis.

Science has a closely held secret: it is full of failures.

Failed experiments. Failed hypotheses. The experience of failure is a rite of passage, a cornerstone in every scientist’s career. To be explicit, I am referring to the day-to-day mistakes every human (scientists included) make, not blatant unethical research methods. Failure is common, and expected. Yet despite its prevalence, few scientists discuss or bring to light their mistakes. Shrouded in secrecy and shame, these mistakes are tucked away.

This perpetuates a sinister misunderstanding of science; that science, and by default, scientists are the peak of perfection in our society. As a result, young scientists are taught to fear failure, to be ashamed, and to even hide failed experiments and hypotheses. This is the fundamental breakdown between the reality of scientific research and public understanding of science.

As science educators, we serve as the conduit between science and the general population. With this unique position, we have the power to connect, disconnect or reconnect the general population with science. It is how we do this that has a lasting impact on our students. We often integrate a culture of error in our teaching, framing our mistakes as learning opportunities, yet this seems to get lost in science. Why is this? I can’t think of a better time or subject to teach failure. Through science we can teach failure as expected, respected and valued.

Failure is to be expected
Failure occurs at every level of science, but is not often seen. More often than not we only see the end results of an experiment rather than the countless failed attempts and accidental discoveries in between leaving us to assume that the entire scientific study was as flawless as the end result. This could not be further from the truth. Developing an expectation of failure is essential for young scientists to understand the scientific method.

Expecting failure more accurately reflects the reality of a non-linear scientific method. We are taught that the scientific method is a one-way road that occurs step by step when in actuality the scientific method is a complex web of steps, missteps, and redirections. When something does not go as planned it is reevaluated and immediately remediated. Bringing this process to light both in scientific communities and in the classroom promotes transparency, ethical practices, and culture of error.

Failure is valued
Failure is the ultimate teacher. By pointing out our mistakes, and providing a pathway to improvement, failure teaches us how to be the best versions of ourselves. Failed experiments and methods provide us with the greatest learning opportunities in science. Unabashedly sharing our failures and mistakes with the world allows others to prevent making similar mistakes, resulting in the advancement of science as a whole. Openly presenting the details and missteps of every failure provides insight into how and why something went wrong. At its core, science is the pursuit of explaining reality, the hows and whys of the world. It is logical then to assume that every failure is not merely a roadblock but a stepping stone bringing us closer to a more accurate understanding.

Failures can result in the accidental discoveries of cures, theories, and technologies. Take Alexander Fleming’s accidental discovery for example: a failed sterilization technique and consequently contaminated experiment resulted in the discovery of penicillium mold that fought the flu virus he had been culturing. This resulted in the discovery of the antibiotic Penicillin, which saved countless lives. Many scientific discoveries have been the direct result of failures, mistakes and imperfect methods. Why should then be so afraid of failure if it has brought about so many successes?

Failure is respected
Respect for failure comes in multiple forms. From recognizing to addressing mistakes, we must respect what failure is telling us. Is this failure informing our practice? Is it pointing to an accidental discovery? Is it telling us that we are looking in the wrong direction? Each failure has a message, one we must listen to with respect if we want to grow from it.

Not only must the failure itself be respected as an opportunity to learn but the scientist who made said mistake must be too. The fear of failure comes directly from the fear of our peers’ reaction. Establishing a culture of error in our scientific communities allows our failures to be shared without hesitation, resulting in healthier, and happier scientists, and students. Respecting failure allows to us to work free of judgment or fear of failure.

Learning from failure is respected in many communities. Why would the scientific community be any different? A fundamental perspective shift must occur in our scientific communities and it starts in early science education. If we teach students to expect and value the inevitable failures of science, we have taught them to respect failure. Only after we have established respect for failure can we successfully establish a far-reaching culture of error in the sciences.

Teaching failure
microscopehelpIn teaching these practices early we can allow students to embrace science as a plastic, ever-changing subject. Breaking down the fear of failure in young scientists is essential for student growth and scientific advancement. We can teach failure by being open and vulnerable with our students when we make mistakes. Modeling the ability to adapt and reframe failures as learning opportunities is arguably the most important step in creating a culture of error. When failure occurs we must celebrate with our students. We should embrace this failure and seek to learn all we can from it.

Recognizing failures as learning opportunities requires a critical look into scientific history. Students should be shown the colorful history of accidental scientific discoveries, where apparent failure turned into unimaginable success. Instead of only teaching the end result of scientific studies, teach the in-between. Show the uncomfortable, the messy and frustrating side of science by drawing back the curtain. This result in a better understanding of the non-linear scientific methods, confident students, and who knows, maybe another accidental discovery.

  

Anyone who has ever tried to mention a popular culture reference in front of Gen-Zer knows the look: eyebrows raised, shame and speculation etched in their face, eyes rolling. But breaking down this barrier can lead to great success in accessing higher-level thinking and discussions of how the latest Internet trend or meme reflects on our society and perspective of the world. Take the latest sensation for example: Yanny vs. Laurel. The seven-second video, which is currently making its way across all social media platforms, is raising many debates. Does it say Yanny or does it say Laurel. People have STRONG opinions on what they hear. After a weekend of debating with my friends over what the video is saying (being only hear Laurel I can’t fathom how anyone could possibly hear Yanny!) I started thinking about using this video to discuss perspectives, with an equity lens, with students.

On the Monday of my next teaching week, sitting in a circle with my eleven students and two adult chaperones, I asked the students to define ‘perspective’. After a quick turn and talk, they gave answers such as “someone’s view” or “different ways to look at something”. I then asked them, ‘can someone’s perspective be wrong?’ The students thought silently for a moment before one raised her hand saying “I don’t think so... For example, if I pointed at water and said it’s blue and someone else said to me it looks brown, we could both be right, we just have different viewpoints... perspectives.” My follow up question: what effects/changes someone’s perspective? The answers included past experiences, your eyesight, your height, your race, your gender, your hearing.

I then asked them if they had heard about the Yanny vs. Laurel debate - about half of them had, while the other half knew what I was talking about but hadn’t heard the actual recording yet. I explained that I would play the recording and I wanted them to silently listen to if they heard ‘Yanny’ or ‘Laurel’. After a playing the video a couple times with the background squeaks of students restraining themselves from yelling out, I asked them what they heard. All at once each of them shouted out their answers and looked in shock at their friends who had heard something different. A few chaotic moments later we had collected ourselves enough to vote by a show of hands what we had heard it was nearly equally between ‘Yannys’ and ‘Laurels’. I then posed the question, why are we hearing different things when we’re listening to the same recording. “We have different perspectives!” one kid yelled out.
“We have different experiences that impact how we hear it!” yelled another.
“Okay, but I really don’t get how you hear Laurel” said a third – a great transition to my next question: “I hear Laurel, while half of the group hears Yanny. We’re all very sure in what we hear. Does that mean that some of us are wrong about what we are perceiving the recording to say?”
The question was followed by a few seconds of silent think time before one student finally said, “well no, our perspectives are personal and just because I hear one thing, doesn’t mean that someone else has to hear the same thing. We can both still be right”. Bingo.

We then spent some time talking about the science of why we hear what we hear – some current theories in the scientific community include if your ears are used to listening to higher pitched sounds you hear Yanny, and lower pitched, Laurel. We discussed that the video has been recorded so many times over that our brains are struggling to get rid of background stimulations in the video, which changes how we hear it. Another theory is that our ears are unable to distinguish between the sound waves of Yanny and Laurel, as they are so similar in shape in this low resolution recording. This too provided a fun conversation with students - our brains are crazy things.

Kaplan shoeDon’t have access to the Yanny vs. Laurel video? The internet is full of other strange photos to use in the classroom. Simply google ‘The Dress’ and you can Kaplan Dressweed through the 3,860,000,00 results, including many photos and a wikipedia page discussing the 2015 viral photo. The question: is the dress blue and black or white and gold? Another photo that can be used to spark a discussion of perspectives is the pink/white vs. grey/teal shoe debate.

Throughout the rest of the week I noticed students thinking about perspectives on their own. On one occasion a student squished an ant and another asked them, “from the ant's perspective what was it trying to do before you killed it? How would you feel if you were the ant?” leading to a very interesting student-led discussion. Another time a student wondered aloud what the perspective of their classmate might be during a team building activity.

We are living in a world where are students are constantly connected and engaging in and with the internet; I challenge you to embrace opportunities it presents rather than fight it - see what happens. You may just be surprised.

  

Criqui SnailI have noticed something very peculiar over the past year while undergoing my teaching practicum at IslandWood. Whether we are wading through the muddy waters near the marsh or flipping over barnacle-encrusted rocks down at the harbor, children primarily use male pronouns when addressing all the critters we encounter. This bothers me, and not because I believe the animals must be referred to by their proper pronouns (non-human animals have no conceptual understanding of what gender is and couldn’t care less about the words coming from our mouths). This bothers me because this type of gendering of the natural world is a result of toxic patriarchal attitudes, particularly males being seeing as the standard and default form of humanity.

Now you may be thinking, “WOAH, don’t you think it’s kind of extreme to attribute a child calling a slug “he” to toxic patriarchy.” To which I would respond, “No.” It may be true that there are no immediate negative consequences that emerge from a group of 4th graders using male pronouns to describe the slug they just found, but the long term effects can be much more detrimental. When the idea that male is the standard gender is reinforced, it can cause an inflation of ego in young boys and a decrease in the self-esteem of young girls. It can lead to boys thinking they are the stronger/better of the sexes and to develop negative attitudes toward anything that is feminized by our culture. It can lead to girls feeling like they are limited in what they are able to achieve within our society. I believe it is my job as a queer, gender-nonconforming educator to do my part to dismantle the preconceived notions that my students have about gender. And the outdoors is a great place for this to occur.

Below are some strategies that I employ in order to get my kids thinking about gender while outside.

  1. criqui wormPronouns- While performing introductions to new students, I express what gender pronouns I use. I usually say something like, “My name is Criqui and I use he/him pronouns.” Some students may not understand why this is necessary, but just explain that sometimes you cannot tell a person’s gender just by looking at them. Even if you think your gender pronouns are obvious, you opening up about gender may make a child exploring their gender feel more secure in your presence. Have students share their gender pronouns as too.
  2. Use “She”- When I use he to talk about animals I find in nature, kids don’t typically make a peep about its sex. But when I use she, the first question is usually, “How can you tell it’s a she?” I like to point this fact out to students and ask them to think about why they so readily accepted male pronouns but feel the need to clarify when I use female pronouns. With animals that I can’t tell the sex, I’ll just say something along the lines of “I’m not sure, but there’s a 50% chance that I’m right.”
  3. Challenge Gendered Anthropomorphization- Giving human characteristics to non-human animals is probably something people have been doing since language was first invented. Anthropomorphizing can be helpful for allowing young people to better understand the natural world around them. But it can also constrain their learning when they can’t view animals outside of human framework. When discussing the sex of animals with students, make sure to challenge any assertions that rely on socially constructed understanding of gender. For example, “I think that squirrel is male because it’s gathering food for its family. The mommy squirrel is at home taking care of the kids.” In this situation I would praise the student for thinking creatively, but then ask questions that challenged this train of thought. “Do only mother squirrels take care of their young? Are we sure this squirrel has a mate? What if this squirrel is too young to have kids?”
  4. Criqui DucksTeach Sexual Dimorphism- You might want to call this something different depending on the age of your students, but sexual dimorphism is a great concept to get kids thinking critically about how sex shows up in nature. Sexual Dimorphism is the condition where different sexes in the same species have notably varying physical traits. Many birds, such as mallards or red-winged blackbirds have different colorations depending on their sex. When students are aware that of this distinction in certain species, they are more likely to remember that not all animals are male.
  5. Slugs- I have encouraged my fair share of kids to kiss a banana slug. It is extremely common for kids to circle around the first slug spotted in the week and gawk at its slow moving body and wriggling tentacula. Slugs are also a GREAT opportunity to talk about gender. Slugs don’t have a sex that can be classified as male or female. When they’re born, they’ve got all the parts to get pregnant and all the parts to impregnate others. This concept usually blows kids’ minds, and last week I had a kid repeat throughout the week, “They don’t have a gender, that’s so weird.” With those sorts of remarks I always to try to respond by expressing that’s actually really natural and happens in so many species that we’ve already seen so far (barnacles, seas anemones, worms). Sometimes I like to say how lucky the slug it since it doesn’t have to worry about gender. “This slug is my role model, but it never has to worry if something it’s doing is too girly or if it is looking too much like a boy. I do my best to be like this slug!”

I’ve found these techniques to have varying effectiveness depending on the group of students. These conversations can often lead into important discussions related to gender in humans, which are invaluable to have in the classroom setting. As issues related to transgender rights and gender non-conformity become more prevalent in our culture, we must prepare our students to live in a world with all types of people. When we engage with our students about these types of topics, we are readying them for a diverse world full of all kinds of people. Keep having these conversations and push your students to think outside of the gender box that’s been placed upon us!

Today we know with certainty that segregation is dead. The only question remaining is how costly will be the funeral.

~ Martin Luther King, Jr.

One of the beauties of being an outdoor educator is having a range of environments at your service. Here on Bainbridge Island, we have the benefit of a historical (and current) cemetery, plus an historical society that shares histories of some of the older graves with us. We have used that information to create informational cards that students can use to teach each other. This allows the students to discover at least partial stories of historical lives, often socially charged lives, with our students and helps to create discussions around those issues. I am often surprised the insights that even 9 year-olds can have when given the chance. Here are a few thoughts on how to establish a social/historical perspective in a cemetery with students:

1: First, check-in: While they can be powerful teaching tools, cemeteries sometimes expose a lot of uncomfortable baggage for students. A student may have a recently deceased relative or a cultural norm that makes a cemetery very upsetting to them. If possible, try to respect those circumstances and avoid the cemetery with those groups unless they give you the go-ahead.

2: Establish boundaries: When your students are comfortable (or relatively so) entering a cemetery, make sure they know how to respect it, and why. Clearly establish your views: do you want your group to avoid walking on the graves? Should they avoid climbing on the headstones? Can they make rubbings of the markers? What volume level is appropriate? How will you get them back to you when time is up? Do they understand why their behavior is important?

3: Let them explore, but give them a task: Send your students out into the cemetery with a mission – “Find this headstone, prepare to teach the group about it, and then explore until you hear my call” – so that they have some direction. This gives them time to notice features of the cemetery while they’re exploring, but also saves time so you don’t have to give multiple sets of direction (free explore, then assignment). Informational cards of specific graves, with pictures, are helpful for this. Be sure to wander around and check in with groups as they’re exploring to gain a sense of any discomforts, questions, and to keep them on task.

4: Hear from them: After your students have found their stones and explored the area, call them back to share out. Most of the time, students are intrigued enough by what they’ve seen in the cemetery that they’re engaged and ready to listen. Ask “what did you notice?” and if you want more, “how did you feel?”

5: Have an observation up your sleeve: Save a big observation for yourself: “I noticed some headstones that were out in the woods – not in the main cemetery. Did anyone else notice that?” * or, “I noticed the cemetery seems to be arranged in sections.” If you’ve explored the cemetery before your lesson, sometimes it’s possible to come up with observations that are both unique and unsettling for your students. WHY would someone be buried in the woods instead of in the cemetery? What does that mean? Why wouldn’t someone have since maintained that grave as part of the main cemetery?

6: Take a group tour: Beginning with your own observation that links to social inequality issues, take a group tour of the cemetery. By modeling a presentation of your chosen headstone first, the students will have a clearer understanding of what they should be thinking about during their presentation. Have each student (or pair of students) lead you to the headstone that they researched and teach the group about its highlights. Be prepared with questions like: “Why do you think that happened?” “Have you heard anything from anyone else that might add to that?” to encourage students to get creative with their answers. This can assist them in connecting more emotionally to the history of the people.

7: Debrief: I like to round out the cemetery visit with an introspective piece such as a perspective story (the students write a story from the imagined perspective of a person who once lived in the area) or an ‘I Am From’ poem (the students write a poem about their own lives and the challenges they have/strengths they have following a template and example that you have). If you’d like them to share pieces of their writing, however, be sure to tell them upfront. Sometimes students write very personal things and they’d rather not share the entire piece, so give them your expectations before they get started.

  

* Disclaimer: As of May 27, 2015, I have not yet received confirmation from the Bainbridge Island Historical Society that the grave-markers in the woods are remnants of past social inequalities. This disclaimer will either be removed once I receive confirmation or I will update the information.