Phenomenon
Life is diverse, yet there are some commonalities across organisms.
We can see patterns of "nested similarity" where some kinds of life are more similar than others.
Among much of the diversity we see, there is a striking pattern where organisms are fairly well matched to their environments.
Question
What might account for these patterns of Unity and Diversity? OR How can all organisms on Earth share so many characteristics and yet be so different? (But have YOUR students generate some kind of reasonable question if possible. If not, give them a question or some questions that you feel are driving for the year. See the end of the PowerPoint for one additional example.)
Model Ideas
No model at this time. Students may have some ideas that explain unity and diversity, but the curriculum does not address model-building for these big questions until the end of the year (see Unity and Diversity Part 2). Acknowledge this and be explicit with students that you’ll come back to looking at this pattern throughout the year and at the end of the year you will draw on multiple models to explain this pattern. They’ll have a chance to see how much they’ve learned!
Overview
Transition in: Now that we have an idea of how science works and how scientists explore the world, we focus in on the specific subject of this biology class, living things!
We begin with an activity that exposes students to a number of diverse organisms: preserved, living specimens, photographs, or a combination. We conclude that Earth is home to an incredible array of vastly diverse species, each well-suited to its specific environment. We also note that though diverse, these organisms have many characteristics in common. Students generate a list that may include the following: are made of cells, have a life-span, reproduce, obtain food, produce waste, have DNA, sense and respond to their environment etc. This leads us to wonder how there came to be so many kinds of organisms that are so very different, but also have so many characteristics in common. This question frames the entire year and will be revisited throughout the year, but especially at the year’s end. Other important questions within this framework include: What are the commonalities that exist among all living things and what evidence supports this? Why do commonalities among all living things exist at all? Why are there so many species and how did they come to be? How does biodiversity among species change over time? What role does the environment play in shaping biodiversity?
Transition out: Now we will explore biodiversity a bit further and ask questions like “What has happened to biodiversity over time?”, “Why does biodiversity matter?”, and “What are some causes of a loss in biodiversity?" Then students will study a specific case of changes in population sizes in a real ecosystem over time and ask “What factors cause the sizes of populations to fluctuate?”
Overall Time: 2-3 Days
Advanced Planning
For Odd One Out activity:
- Gather preserved or living specimens (4-5/table - see teacher notes and powerpoint for examples)
- Alternatively, print card with pictures of different organisms for each table.
Segment Title
Learning Segment 01
1. Students explore the phenomenon of biodiversity. Students work in groups on an activity called "The Odd One Out", which showcases some of our planet's biodiversity in sets of 4 or 5. At each station, students must decide in their group which organism is the "odd one out" and record their reasoning.
Our planet is full of wonderful and diverse organisms, and as different as they all are, they also have some similarities. In the next learning segment we will discuss these similarities and differences.
Segment Title
Learning Segment 02
2. Students process the activity and work to describe patterns of unity and diversity. The class processes the previous activity and generates a list of unifying characteristics of life. Students explore two additional patterns. "Nested similarity," the idea that some kinds of organisms are more similar than others (despite the fact that ALL organism share certain features) emerges from "The Odd One Out". Students then see a second phenomenon by looking at three praying mantis species. Students may observe that species' characteristics are related to their environments. These additional big patterns round out the list of phenomena students will use to generate an overall driving question for the year.
With all the diversity of life on our planet there are several characteristics that every living organism has in common and this list is now posted in our class.
We learned that people have wondered about the similarities and differences of organisms and have worked to classify them in to categories.
We also figured out that the environment plays a role in how even very similar organisms can appear very different.
Segment Title
Learning Segment 03
3. Students generate a driving question (and perhaps sub-questions) for the year. Your students have now seen a broad pattern of unity and diversity among biological organisms. Additionally, they’ve seen patterns of “nested similarity” and the match between organisms and their environment. All of these observations constitute the Big Phenomenon for the year.
We formed a question about life on this planet that will drive the year’s instruction. We wondered about the phenomena of life being so different yet having several similar characteristics, and we wondered about the role the environment plays in all this unity and diversity.
We will work throughout the year to develop a series of models that will help us answer our overall question at the end of the year.
In the next series of learning segments we will reason about Population Dynamics and Extinction.
Download Resources
| Attachment | Size |
|---|---|
| Unity and Diversity Part 1 vBio.zip | 16.02 MB |