One of the few things I remember from my high school biology class was watching a movie called Lorenzo’s Oil — a 1992 film about a boy with a rare and deadly genetic disease. I’ll admit – I don’t remember anything else about the unit or any of the activities we did. I don’t really remember anything else about the class. I don’t even remember my teacher’s name (although I do recall what she looked like)! You get the point – I don’t remember much about that class – but this phenomenon stuck out to me… and I’ve always remembered that!
Teaching with phenomena can be so powerful, and that’s why I am all about phenomenon-based teaching now. So anytime I start a unit, I first focus on
- identifying my target content
- selecting my phenomenon
And so when I started my heredity and genetics student-driven storyline, my first stop was choosing an anchor.
Genetics And Heredity Through A Conservation Lens
Inspired by my time at the San Diego Zoo with the Teacher Conservation Program in 2016, I knew I wanted to bring endangered species and conservation genetics into this unit. But I was also drawn to the kind of forgotten events of early 2020 — the Australian bushfires — and through a winding yellow brick road, I ended up finding my way to a focus on cute cuddly koalas and what scientists have uncovered in their genomes.
Endangered Genomes: Koalas At Risk
Identifying the anchor phenomenon isn’t enough to launch a unit. Students have to engage with it. So in my first anchor experience, students are tasked to act as researchers working to obtain funding for a koala conservation effort. As students learn about the unprecedented 2019-2020 bushfire season in Australia, during which as many as 60,000 of the country’s estimated population of 330,000 koalas were killed, they establish the context for the unit — how we can save species and what roles genetics can play in that mission.
In this full lesson designed to truly engage students with the phenomenon, students analyze data and scientific texts (maps, graphs, species fact sheets, scientific texts adapted for student use) to complete their initial application for the Queen Mary’s Zoo Conservation Symposium. Their application documents student observations from the resources provided, as well as initial questions that students will use to carry out this unit investigation. It sets students up to pursue the three primary pathways:
- Why are koalas endangered? (Resource availability and changes in ecosystems!)
- How do koalas survive on poison? (Genetics, DNA, and mutations!)
- How can genetics help save species? (Sexual reproduction and heredity!)
Developing Questions From The Anchor
When it comes down to it, this anchor experience is designed to spark questions like: Does resource availability affect populations? How do environmental and genetic factors affect growth and reproduction? How are traits passed on? Can we help biodiversity? More specifically as related to this phenomenon, students will ask (and answer) questions like: Why are koala habitats so limited? (Resource availability! Human impacts!) How can koalas eat primarily toxin-rich eucalyptus leaves? How do new traits and/or adaptations emerge? (Genetics!) What happens to organism health when genetic diversity declines? (Genetics!) Why are koala populations endangered? (Human impacts!) How can we help maintain biodiversity?
While this anchor experience is designed to open a door into topics like changes in ecosystems and resource availability, we’re going to focus this post on the genetics and mutations elements of this Curiosity Spark! [Stay tuned for the next installment – moving on to sexual reproduction and inherited traits!] Let’s dive in!
How Do Koalas Survive On Poison?
As I dug into koalas and the discoveries scientists made through sequencing the koala genome, I found the ability of koalas to survive on a diet that would kill most other species so fascinating! And that’s where the first “pathway” in our student-driven storyline begins.
In the lesson, Why Are Scientists Collecting DNA?, students begin their exploration into genetics (and how it explains koalas’ unique dietary choices) by exploring a new phenomenon – conservation of African wild dogs! (Layering phenomena keeps students engaged and provides opportunities for students to practice and apply their understanding to new situations!) So first, students are introduced to karyotypes and chromosomes to identify the genotype and phenotype of fictional African wild dogs. Then, students transcribe a specific DNA sequence and build a DNA model in order to understand what DNA actually “looks like” and how it records information about the traits of individuals. It’s students’ first steps into understanding how DNA “codes for” traits!
While this lesson introduces the concepts of simple inheritance patterns (dominant and recessive) and how those are “recorded” in alleles on chromosomes (and also focuses on the structure of DNA), it stays surface level at this point. It does not introduce sexual reproduction, Punnett squares, or the mechanisms behind the idea of “genes to proteins to traits.”
That’s – of course – still to come!
From Genes To Proteins To Traits
So once students have the general idea of what DNA is and how it determines our traits, they are ready to dig into the mechanisms — the “genes to proteins to traits” flow. And that’s where I go next. In How Do Genetic Differences Explain Observable Traits?, students dig into mutations through (yes) another phenomenon. This time, they’re exploring fur color variation in rock pocket mice populations by analyzing and comparing short sequences of DNA to identify mutations. Bringing in the hands-on again, they develop a model to uncover and illustrate the structural changes to proteins that result from changes in DNA.
And of course, in our phenomenon-based storyline, we have to make those connections back to the anchor. So in this activity, students are asked to wrap up by applying their growing understanding to the initial anchor — the genetic adaptations that allow koalas to break down toxic terpenes in their eucalyptus leaf diet.
Coming Back To The Anchor: Genetics, Mutations, and Koala Adaptations
Now with that in mind, I found this moment to be the perfect opportunity to address that funny little standard that no one knows what to do with (lol) – MS-LS1-8. “Gather and synthesize information that sensory receptors respond to stimuli by sending messages to the brain for immediate behavior or storage as memories.” Because its the unique genetic mutations in the koala genome that enhances their ability to taste and smell bitter (and water, so crazy!!), the connection is so easy. So for this next activity, students dive into some scientific texts from Frontiers For Young Minds (great resource!!), as well as some we developed, to answer the question, How Do Koalas Senses Influence Their Behavior?
You can access this activity for free (after December 1, 2021) when you create your SparkLITE account. Register here!
In this literacy-based activity, students synthesize information from several sources to provide evidence that koalas use their senses of smell and taste to optimize their food choices. By encountering information from several sources and working to put that information together in support of a claim, students are practicing the Science and Engineering Practices, Obtaining, Evaluating, and Communicating Information as well as elements of Engaging In Argument From Evidence.
Moving On To Heredity
At this point, students have developed a strong understanding of DNA and how it determines the observable traits in organisms. They’ve explored the concepts through three dimensional lessons, uncovered the big science ideas, and then reinforced those through opportunities to connect back to the anchor phenomenon. They have also reviewed those concepts through this Curiosity Spark’s student text — Endangered Genomes: The Science In The Story.
Students are ready to dive further into the phenomenon — looking at how genetics can play a role in ensuring the health and sustainability of endangered populations. To do this, we have to introduce another phenomenon, — one that we will dig into a bit more — the California condor.
But we’ll chat about that one next time.
I have your next student-driven storyline…
You can grab this entire storyline framework – from anchor experiences to assessments to the explorations described here – when it launches on December 1, 2021 when you join the Spark Subscription! Click here to learn more.
Bring Wonder Back: Becoming A 3D Teacher
If this type of learning sounds like something you want to embrace, but you aren’t sure where to start (or you just need a refresher), Bring Wonder Back: Becoming A 3D Teacher is perfect for you. This free workshop series is designed to take you from 3D-huh? to a prims-master. What? I don’t know. My point is, you’re going to walk away knowing what 3D teaching is and what it looks like in the classroom, on a lesson level. In a few short videos, I’ll walk you through:
- the mindset shifts we need to make in order to embrace a new, 3D teaching approach, (so you can actually prepare your students for the demands of their futures)
- what phenomena are and how they fit into your curriculum, (so you can create a classroom built from curiosity and intrinsic motivation)
- teaching through exploration and discovery, (so you can shift the work of learning from yourself to your students)
- and what 3D teaching looks like, (so you can see how the pieces of the puzzle fit together seamlessly)
You can sign up to access Bring Wonder Back: Becoming A 3D Teacher right here!