Evolution & Extinction (Day 2/2)
Lesson 8 of 11
Objective: SWBAT define extinction and describe how meteorite impacts can cause mass extinction events and have altered the evolutionary history of life on Earth
This is the second day of a two part lesson covering evolution and extinction, which are similar concepts in how they affect the fossil record. Students watch a (great!) video clip and examine the impacts of mass extinctions on the fossil record, and explore the idea of exactly how extinctions can impact organisms on a global scale. Like all of my lessons, there is a heavy practice component with an exit ticket/daily summative assessment which collectively addresses the content from both this and yesterday's lesson.
[Note: For embedded comments, checks for understanding (CFUs), and key additional information on transitions and key parts of the lesson not necessarily included in the below narrative, please go to the comments in the following document: Evolution & Extinction (Whole Lesson w/comments). Additionally, if you would like all of the resources together in a PDF document, that can be accessed as a complete resource here: Evolution & Extinction (Whole Lesson)[PDF]. Finally, students may need their Earth Science Reference Tables [ESRT] for parts of the lesson (a document used widely in the New York State Earth Science Regents course) as well.]
The above video is an additional "hook" which I use to get students talking about extinction events. It's a clip from Deep Impact, a mid 90s film about a comet on a collisions course with Earth, and the actual clip is the affects of when the comet actually hits the Earth somewhere in the Atlantic Ocean.
I don't have anything particular in the general resource to have students copy down - I just ask them to note (before playing the video) what the affects are of the comet's impact, and if they think those affects are realistic.
After the video is seen, I call on some students for some general reactions to what they saw, given the questions above. But then I add the point that, despite the immense size of the wave and the extreme destruction it caused, it's unlikely even a wave of that size would be able to affect all of the Earth's organisms. Then I ask - "How do you think something like a comet or asteroid impacting the Earth can affect organisms even on the other side of the world?" I then take a few responses (it's okay if they're not close yet!) and then direct them to the notes section below.
In the Extinction Notes, students get an answer to the question in the previous section. Not only do we define exactly what extinction is, but we discuss how external forces can cause extinctions on a global scale. On the first two pages of the resource, students have a text to read in addition to some brief checks for understanding that assess their comprehension of what they've been reading. They are asked about extinction events, what causes them, and how those extinction events actually work their magic and cause the global havoc that they do.
Students are asked to read these together (with their table partners) and answer the associated questions as they read - pulling information and evidence from the text as necessary to assemble their answers.
The Extinction Practice in this lesson is similar to the practice resources in most lessons. Students utilize their Earth Science Reference Tables [ESRT]/Geologic History Timeline [ESRT], in addition to their notes, to answer the questions. The first question, Sample I, is one I generally do a model/think aloud for students about. I show them how to use the information in their reference table to attack questions, eliminate wrong answer choices, and arrive at the correct answer [Note: See reflection in this section for the way in which I might model this process].
In terms of student work habits, I tend to sometimes make this decision in the moment, and as a response of what I know about the students and how they're processing the material on, but I'll either ask them to work independently, in partners, or give them the option. Usually, before starting practice, we tend to go over some steps for self-help ("What should you do if you're stuck?"), and I might reference a previously used multiple-choice or free response strategy in order to build their skills while simultaneously learning content (as an example - one popular one we always use - "If you aren't sure what the right answer is, see if you can eliminate some wrong answer choices"). I tend to circulate for compliance and then hone in on specific students while they're doing this.
After about 10 minutes, we go over their responses. We use a combination of strategies (active voting, cold calling, popsicle sticks, volunteers) to go over the responses, where students correct their work and ask any clarifying questions.
In the last few minutes of class, I have students complete the daily Exit Ticket, which for this lesson covers content from two days (Day 1/2 featured here). For the sake of time, I have students grade them communally, with a key emphasis on particular questions and items that hit on the key ideas of the lesson (Note: This usually manifests as students self-grading, or having students do a "trade and grade" with their table partners). After students grade their exit tickets, they usually pass them in (so that I can analyze them) and track their exit ticket scores on a unit Exit Ticket Tracker. I also pass out the Homework at this time.
After students take a few seconds to track their scores, we usually wrap up in a similar way. I give students time to pack up their belongings, and I end the class at the objective, which is posted on the whiteboard, and ask students two questions:
- Do you feel that you mastered the objective for the day?
- Can you reiterate one thing you learned about ____________ (in this case, basic questions about extinction, etc.)