Remote / In Person Lesson plan designed by Kai Medina
Objectives: To provide an introduction into the workings of evolution, more insight into ecology and the cool stories within it, demonstrate how the science is still ongoing and changing, and engage with misconceptions. Finally, allow students to look at any animal and make guesses towards their origins.
The whole lesson will be leading to the last session where, using what they've learned, the students try to solve that final question; why, on multiple occasions in evolution, has a creature taken a crab-like form?
Above all, aside from the very basics, this lesson should bring forward cool creatures and great stories, as this will both keep their attention and garner an interest in biology above the cellular level (which is all I was ever taught aside from super basic stuff up until senior year of high school).
Slideshow I put together: https://docs.google.com/presentation/d/1Yavc673hMsXNZd3hxEIbPAW-BMZX1zuXx1Q0cZOm5X0/edit#slide=id.gcd623ab68e_0_1
While the slideshow was designed with a sort-of order to it, it was made to also jump around based on student interest, questions, time, and how things are flowing. Please feel free to copy it and modify however you need (proper credit given of course if you use it anywhere outside a classroom). My class had four 1-hour sessions over the course of two weeks, and I do wish I had more time, but when moving through stuff I was able to get most of what I needed in. This was made for a middle school audience but honestly I try to design this stuff to work for anyone - as we all come from different backgrounds.
Note: Slideshow template and animal imagery comes from here: https://slidesgo.com/theme/evolution-as-such
Special thanks to Prof. Wasserman from Boston University for help finding some of the video content, and for leading an amazing class on ornithology. Big thanks to the MIT's Afterschool-tastic program for giving me the opportunity to design lessons like such. Final thanks to Tara Srinivasan for help editing.
Introductions
1. Give context to the class title - Carcinisation is the word used to describe how on multiple occasions in evolution a creature has taken a crab-like form. My students all joined the class based on memes they saw previously on the topic.
2. Next, I showed videos (see right) of some interesting creatures, while using them for later discussion. The Widow bird can be connected to the topic of sexual selection, and how it has a super long tail, harmful for flying, while jumping up and down in a field where predators can spot it. Why did natural selection lead to this? The sea robin is just an interesting design to look at, and can touch on convergent evolution later on with its 'legs'. Finally, the Drongo bird uses vocalizations to both warn meerkats of predation, and then uses that to trick them and steal meerkat food. I tend to start the Widow bird at 50 seconds, and Drongo at 40. Don't use this moment to really push educational stuffs, but call back to it later on. This is just part of our hook.
3. Student introductions if it's a new class. Have them share names, pronouns, and one question they might have on evolution or a specific creature.
4. Schedule - just give a brief outline on what this section is gonna look like as a whole, and what the students will come out of it with (see Goals image up above).
Evolution Basics
Again, I moved around topics based on what works for my class. Have everything ready beforehand in case interest drives discussion to a later topic. See the slides for added visuals for this content. This section filled an hour and a half of class through discussion, questions, and examples.
What is natural selection?
Evolutionary Arms Race
This discussion was very successful for me using the hawk and mice example in the slides. Bring up the scenario and have students guess how things might evolve in this setting. An example would be the mice would change colors, the hawk's vision would then get better, the mice get pointier hair, the beak of the hawk changes, and so on and so forth. This really helps drive a stake in the misconception that evolution is trying to get somewhere, like everything prior to the dolphin was evolving to become a dolphin.
I didn't initially plan for this (thus the underwhelming slide), but the terms generalist and specialist took hold here and really drove discussion.
Survival of the fittest
Ask them what they think it means. I got answers like "strong" or "good at defending", now we can transition to our next topic on niches. This shows that survival of the fittest means a species becomes fit for its very specific spatial and temporal environment.
DNA
What is DNA, what makes the 'code', how do mutations happen? Demonstrate how a single mutation or a couple really don't do that much, but instead change over large generations. Additionally really go into what a mutation is, as my class all came in with either hulk like thoughts or that humans and animals are mutating and evolving to adapt to climate change.
The genetic toolkit is something I've found to be undertaught. This is the idea that a lot of genes stay there even if not used, like how we can get dinosaur features out of a chicken. There are a series of on/off switches in our code that can suppress certain genes, but this can be unsurpassed if advantageous with the right small mutations. Additionally not every change is so much from scratch, as say chemical levels and proportions from both how the body disperses them and what comes in from the environment (shrimp turning flamingos pink) can have an effect. An important note is also that noise kinda takes over over time, and so it's not something that will be there forever. You won't see humans producing fins out of nowhere.
Diving into it and reinforcement
Simulating Natural Selection
https://beltoforion.de/en/simulated_evolution/
The rectangle food outline also helps with the idea of 'island biogeography theory', which is how animals can jump onto nearby islands. The creatures in the simulation will be mainly center focused, but then one might escape to the out-lands and breed for a short time, but then become too overpopulated for the food source.
If possible let the students play with these themselves instead of streaming it all to them like a video.
"What would you say to someone who says..."
Intersperse these prompts among the lessons naturally. Promote engaging conversation, as opposed to 'you're dumb' or 'because that's stupid'. They should see themselves as teachers instead of debaters.
"We evolved from monkeys"
Discuss how evolution isn't a straight line where, say, whales evolved from dolphins which evolved from sharks, but several lines branching off each other, from common ancestors.
"If we're animals, then climate change is natural and we should just let it happen"
"Why should I care how things evolved? It doesn't affect me!"
"An invasive species got there and was more fit, why should we remove it?"
Humans
This can be a really tough topic to talk about, but it is very important, as any topic of evolution involving humans can skirt eugenics. Do not be afraid to talk about this, as it is a misunderstanding that can stay there if not otherwise engaged. The macro/micro evolution topic below is also a good place to start, so consider if you want to teach humans first or that topic of evolution first.
Humans are not currently evolving on a large scale, only via microevolution with slight changes in skin color, receptiveness towards certain medicines or ailments, etc. Population dynamics and gene frequencies. I feel this is one area I need to learn more on how to talk about it in the classroom, as this is a very large topic. I implore you to do further reading such as below and reference other academics more experienced in this lesson.
Another discussion topic is 'how did humans escape the food chain?', or 'what was our niche?'. There's many ideas on this, and it'll be productive to have your class discuss possibilities. In the end our intelligence, language capabilities, and our running endurance lasted. One of our niches might have been feeding on bone marrow! We also weren't the only people on this planet. Not only were there neanderthals, but several other slightly different species/subspecies (at this level it gets difficult to define species, with its 40 alternate definitions, when things can interbreed and especially when humans are involved). And they weren't as hugely brutish compared to humans as media would make out. They had very similar brains, and complex emotions and whatnot didn't just come out of nowhere. There has been clear evidence for empathy (and not just in human like species too!). I recommend the video below on this topic.
Artificial Selection is another great topic to touch on, where in dogs, cats, fruits, and other flora/fauna had specific traits we like. So, we chose to select and perpetuate breeds that show those traits more than others. There's great imagery online when you look up what original species of say, the banana, looked like. Additionally emphasize that this isn't mutations happening really fast, but instead taking things that are already there, and selecting variations we like. The x chemical in this fruit might be produced more in this one, so we'll plant its seeds.
Macro vs Micro Evolution
One big question that you should be spending a long time on is 'how fast does evolution happen'?
First we would need to define Macro vs Micro evolution.
Microevolution is on a small scale, within a single population. While all evolution is a change of gene frequency over time, here we really are just caring more about the proportions of genes (see artificial selection below as well). This is when butterflies wings might change colors slightly, hair and skin melanin levels might change, and so on. This is small scale and does happen, like when a white moth turned darker due to the industrial revolution smogging up buildings. It is to be emphasized that this is *not* going to produce any large scale changes like a new arm or humans with wings. No creature is able to adapt quick enough to climate change, be it humans or wildlife, which is a confusion I've heard from students. Macroevolution is the larger scale stuff. This is evolution "above a species level". Changes will happen that form new species and over immense periods of time create long lasting change. According to certain studies, lasting evolutionary change takes about a million years. Reading below, and put some thought into if you'd want to teach this unit before or after the human unit.
Discussion: Which might evolve 'faster', a bug with wings, or a bug without wings? Ask them this at the end of a relevant lesson, and then have them discuss at the next class. Two possible thoughts on this would be that the bug with wings can fly away, so it doesn't have to concern itself with specific threats as much. Though that may bring it new threats, and will definitely cause it to land in new environments to adapt to. Evolution can happen at different rates for different things. Possibly also discuss background extinction levels here.
Animal Abilities compared to Humans
Ask the class: "What can a human do that another animal can't?" Obviously stuff like build a TV or run a country, but what about building in general? Social Hierarchies? Turns out animals can do a lot! Leaf cutter ants farm leaves to grow a fungus. Other ants have wars, slaves, false monarchs, and herd aphids like cattle! Bees keep drunk bees out of the hive until they sober up. Octopi use coconuts for shelter and will punch fish out of frustration. Elephants show grief, and hold funerals. Chimps and monkeys entered the stone age and wild parakeets have names. Our brain didn’t evolve out of nowhere and suddenly get 10 new parts to it. It’s easier to think things don’t matter, it’s easy to say something different is lesser, but don’t take the easy path.
Pre-tree introductions: What is and how do scientists make an evolutionary tree?
Ask the class first and jump off of their ideas.
The Fossil Record
Genetic sequencing - seeing how similar DNA is
Looking at bones / Embryo
See video, especially at 2:55 - 5:20 and 13:00 - 15:20
Discuss what a transitional fossil is
The Big Tree Project
The Project: Introduce this early on, so students can prep for it and come to class with flora and fauna in mind. They will be working together through evidence based guess work, like real scientists, to put together an evolutionary tree. This will combine both animals of their choice, and ones you throw in that are interesting. For instance bees and bats will bring forth convergent evolution. The squat lobster (without revealing it's name) and other false crabs will contribute to the theme of class: why do things keep evolving into crabs! The man o' war isn't actually a jellyfish, but a colony of other creatures making a jellyfish like being. Get creative, and get them creative!
End result: Compare their end result with the real deal, by plugging in all the creatures into a generator (link below). This may take some time outside of class, but it's worth it! This will both show how much they got right, and provide meaningful insights into where things went wrong. This is science, and we have to constantly change the Latin names and locations of creatures on the tree based on new discoveries! Print out a poster with both their work and the real deal to hang in the classroom, or better yet as a take-home for the students so everything will be reinforced for years to come!
Timespan: This lesson would be done preferably over the course of multiple classes after the very basics are taught, but in my case we didn't have that time, so we spent one of our one hour sessions on it.
Multiple Classes of Different Students: Make it a competition! Which class can come up with the best tree! If they look up stuff beforehand, they're still learning stuff outside of class so that's a win, but don't hint at that. Any explanation they give has to be backed with similar traits, fossil records, bone comparisons, etc. Only real methods of making these trees, not just because some website says they're related.
Links:
Tree data: https://www.ncbi.nlm.nih.gov/Taxonomy/CommonTree/wwwcmt.cgi
This site will let you plug in taxonomic names and it'll put together it's tree relations. This and the next site might give you some trouble on specifics. Look into alternate names, look at the higher level classifications, and worst case photoshop in an extra line later. Save the data as a phylip tree.
This link also does it but only allows ~10 creatures at a time without paying https://phylot.biobyte.de/
Visualizing data: Take the phylip tree data and plug it into here: https://itol.embl.de/ (upload button at the top). This will let you organize your tree a bit nicer.
Mindmap Notes: https://apps.apple.com/us/app/mindmap-notes/id1522142579?mt=12&app=itunes&ign-mpt=uo%3D4 I used this app to put together the students tree with them live (remotely) through screensharing. There is other software like this (use the term mind map when searching), this is just the best one I found that was easy to use and change for evolution.
Export the itol tree and your mindmap tree, and combine it for the final poster comparison in photoshop or the free photopea https://www.photopea.com/
Example: See the photo at the top of this post.
Other misconceptions to cover:
Religion vs. Science?
Religion and spirituality are the why and science is the how. These two ideas can easily coexist. We don't want any students saying that because of the Bible, evolution is false, and we don't want any students going hardcore atheist saying that evolution proves religion wrong. Cover this sensitively, but I do think it is important to cover if you won't get in trouble with your district.
Darwin was right so he must be a great person!
We must not mistake achievements and work for the person themselves. Darwin was still human, and far from perfect. He ate one of every creature he found. He got seasick at dock, took a long time to figure out how to use a hammock over the second voyage of the Beagle, and sat on his evolution findings for decades until someone else was about to publish similar findings.
The evolution of evolution - how different cultures explained the differences in creatures, the theories on giraffes stretching their necks so that their kids would have longer necks, approaching the modern day and how we go about it.
Xenobiology Homework
Well, depending on the setting, maybe don't phrase it as homework. The whole idea is to have each student come up with aliens on their own time, and work on them after every class based on what they learned. In the final session an alien zoo can be created, where each student shows off their alien. You as the teacher, or fellow classmates, then ask "What does this part do", "tell me about that", "why did it evolve so many eyes". If they don't know, then you can ask what their theory would be if they saw it in the wild. If there's extra time, the students can work on putting every creature together in a functional ecosystem while more ecological topics are covered. Even further, you could put a cow in the mix and discuss invasive species.
The Finale: Why does evolution keep making crab like creatures?
Give the students time to figure out possible explanations using what they learned, then show them this video or a video like it. Afterwards refresh the students on how far they came, and how we achieved our initial learning goals! You could also intersperse images of false crabs and real crabs and have them guess which is which - to show hey, we make mistakes like this in science too. We're still discovering great new things!
Other Various Resources and Whatnots:
iNaturalist: An app/website that allows the user to submit photos/location data, and will attempt to identify the species best it can. It's crazy accurate. Additionally if enough people support the identification it is entered into scientific databases. Finally, some cities even hold competitions called bioblitz, where they see which city can get the most species in a given time! Boston Harbor will sometimes have free boat rides to outer MA islands for this reason. A group can be made in this for your class, and it can help the evolutionary tree as students bring species ideas local to them to class!
Discuss extinction events, and the human caused sixth extinction
The discovery of the living fossil: https://youtu.be/HJ3yLh_CYg4
The bowerbird's grand performance: https://www.youtube.com/watch?v=1XkPeN3AWIE&feature=emb_title
Elephants & Language: https://media.hhmi.org/biointeractive/click/animalsounds/#/
Why would cicadas come out every ~17 years
Content Changes
I recommend switching up the content a bit based on your audience, and also what you as a teacher feel capable of covering. A lot of my lessons focus on birds because I just had a great ornithology class. While I know stuff about plants and fungus, I completely forgot to cover them in much detail, and I don't know if I even would have the time aside from the basic level. Vocabulary such as producer, consumer, decomposer, and anything else related to ecology slipped in more as I was talking than what's shown on the slides. This stuff is usually covered in elementary school (though to my annoyance my experience was solely those terms and weirdly specific botany), but just name these in a way where you can check your audience on what they're familiar with while keeping interest. If any student present is super knowledgable on topics they can be given a role to help teach, describe, or bring content out. With more time than I was given to teach, I would STRONGLY recommend interspersing more activities, content, and stretching out the evolutionary tree as a background activity for the whole thing.
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