Fossil Record Experience
Lesson 9 of 17
Objective: Students will be able to create a model evolutionary tree using fossil records and morphology.
To engage the students in the lesson, I have students write a chain note about the topic "Fossils provide evidence for evolution".
The chain-note starts with one student writing the question, "How do fossils provide evidence for evolution?" on a piece of binder paper and writing a response in a complete sentence. When done, the paper is then passed from student-to-student within a table, with each student adding an idea in a complete sentence. I tell them to read the previous responses because they should not write down the same thing as another student.
Once the chain-note returns to the initial student, I tell the students to keep it until the end of class. (They will be adding to it and turn it in at the end of class.)
I like using chain-notes to get students back into an idea we have already discussed because it gives them a sense of what they already know and sets the stage for what is to come. I also use chain notes when I'm introducing a new concept to elicit prior knowledge, or after a lesson for a quick assessment. Here are a couple of examples:
I tell the students that today they will be working as paleontologists. As scientists, they have just received a box of fossils. Their job is to carefully look at a series of "fossils" and arrange them in order so they can determine the evolutionary path of the mysterious Adventurian organisms. I distribute one copy of the lab instructions per team, and ask students to read them carefully. Once the reading is done, I write morphology on the board, and ask for a definition. I have students underline that word on their papers, and write the definition on the board, where it will remain for the rest of the session.
I then ask the students to "tell" me what they have to do, step-by-step. This is done by selecting one random student, and having him/her identify the first step, then selecting a second student to identify the second step and so on:
- Cut the chart paper in half and tape/glue it back together, vertically.
- Create the table - including the "math"
- Cut the fossil page, keeping the era/epoch names with the corresponding organism.
- Set the mystery fossil aside.
- Arrange the fossils in order, on the chart.
- Rearrange the fossils, by placing them in vertical lineages according to morphology.
- Glue the fossils in place.
Finally, I ask one more student to repeat all the steps. If s/he can't, a second student is asked to repeat all the steps to the previous student, who then states them for the class.
Note to teachers: It might seem that this repetition of the direction is unnecessary. However, you'd be surprised at how often students will cut the names out of the fossils, or cut them and place them randomly on the chart, if they create a chart at all. At this point, we are really re-creating the data from which they will make their observations, so it is imperative that it is done correctly.
Once the instructions are clear, and we have all agreed on "what to do", I have students gather the rest of the materials they need (chart paper, glue sticks, ruler, markers, scissors), and have them get to work.
At this point students are constructing an evidence chart. As the students are working, I move about the classroom, checking in with students that might need some help. It is useful to point out to students that everyone should be participating, whether cutting, measuring and drawing the chart, helping organize the fossils, doing the math, etc.
Once the charts are done, I distribute the fossil lab analysis questionnaire. For the sake of accountability, each students will turn in their own. However, there is accountability to their group. I do this by telling students they are expected to have similar answers because they should be discussing what they see.
The first question is about identifying differences between the fossils of different eras, and encourages students to notice patterns (CCC Patterns). The rest of the questions, are more analytical in nature and require that the students make inferences based on their observations (SP6). In the student work (SW1, SW2) we can see just how the students practiced these two standards.
These questions provide great opportunities for discussion between students, as they defend the environments they envision for the organisms, as well as decide which species was more successful (the obvious choice being gray heads). Except for question two, there are no real right or wrong answers, the real learning is happening in the discussion the students are having about the evidence as they defend their explanations.
Watch as students go through the whole process of science as they work through the lab. Did you catch the student trying to make sense of the placement of the fossils?
Remember the chain-note from the beginning of the lesson? This is where it comes into play again, as I tell the students that each table must now read through it, discuss their original ideas and "star" or highlight any that might have changed because of what they experienced in this lesson. Finally, each table must add one more sentence to it, and turn it in.
I collect these chain notes, and go over them looking for any misconceptions that I need to address, however, they are not "put into the gradebook", just simply given back with the addition of any needed comments.