Sources & Attributions  Navigation  Using & Copying
 Lesson Structures    Feedback  Appeal for New Lessons
 Topics Outline   Unit/Curriculum Plans 
  Nature of Science  Evolution  Origin of Life

Intended Audience/Grade Level
 These lessons are intended for use in any high school biology course. However, many can be used in middle school / junior high school life science and earth science classes, possibly with slight modification depending on teacher's style and approach, and the experience and level of students. Many would likewise be appropriate for use in junior college or lower division university levels.

Sources & Attributions

Most of the lessons found on this site were introduced at various times during the ENSI Summer institutes. They were reviewed, revised, and shared with the institute participants. Subsequently, they were used in the classrooms of the participating teachers. At followup sessions, problems and revisions were presented and discussed.

In preparation for this web site, all of the ENSI lessons were reviewed by the ENSI faculty. The selection criteria for use on the site included:

1) relevance to the ENSI concepts,
2) overall quality, and
3) use of human examples wherever possible.

The lessons selected for the site were modified as appropriate to fit the "universal structure" adopted for the site, and fine-tuned to the satisfaction of the faculty.

Every effort was made to determine the authors and sources of these lessons, as well as the revision authors, and this information is included with each lesson. Some of the ideas in these lessons may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.


The lessons fall into three major areas: NATURE OF SCIENCE, EVOLUTION , and ORIGIN OF LIFE. Within each area, the lessons have been placed into specific topic categories, based on the focus topics of the ENSI program. Some lessons could fit into two or more topics, and this is usually indicated in those lessons, often with appropriate cross-links.


  • Realm (nature) and Limits: uncertainty, tentativeness, contingency, pseudoscience
  • Basic Processes: problem solving, hypothesizing, testing, critical comparison of criteria
  • Science's Social Context: bias, values, historical constraints, collaboration


  • Geology/Paleontology: age dating, geological history, plate tectonics, timelines, fossils, extinctions
  • Paleo-Anthropology: human evolution, the fossil evidence
  • Classification: hierarchy, relationships, cladistics

EVOLUTION Processes:

  • Adaptations, Imperfections, Contrivances
  • Variation and Natural Selection
  • Speciation: including co-evolution
  • Macroevolution: mass extinctions, punctuated equilibria vs. gradualism, neoteny, mosaics


Navigation Short-cuts

 Individual lessons can be accessed only from one of the three Lesson Catalogs:


On each catalog page listing the lesson titles, there will also be a list of synopses for each title so that you may survey the lessons before selecting a title, which then takes you directly to the desired lesson.

SHORT-CUT: In the future, when you enter the Home Page, looking for lessons in one of those three categories, just click on the appropriate part of the logo:

  • Nature of Science lessons: click on the ?-BLACK BOX
  • Evolution lessons: click on the SKULL (Homo erectus)
  • Origin of Life lessons: click on the bright GALAXY (to the
    right of the skull)

These logo clicks will bypass this general section on lessons, and take you directly to the list of desired lessons.

TRY IT! (click here for the Home Page)

Using & Copying Lessons

You may print hardcopy of any material on this site directly from your net browser, or you may copy and save the material to your system, and then access it offline with your word processor for modification and printing for your personal use. All we ask is that the lessons be used essentially in the manner and context described and for the purposes intended, in keeping with the ENSI concepts. We also ask that proper credit be given to ENSI and the appropriate author(s).

Copy/Save/Print: The best way to save and print any text material (e.g. all the information for a lesson):

With the desired lesson showing on your web browser screen...

1. Select All (this is "command-A" on a Mac); all text will show white-on-black.

2. Copy (command-C); this copies all selected text to your clipboard.

3. Open your wordprocessor, and open a new page (command-N).

4. Paste (command-V); this will put the copied text on that page.

5. Save the document (properly named) for future access, processing, and printing.

6. Return to your browser to directly copy or print any pdf documents for the lesson, or to see another lesson.

Adobe pdf Format: In some cases, student handouts have been created which are formatted in a particular way, or they contain tables or diagrams. So, a pdf-formatted version has been created with Adobe Acrobat, which you may read using Adobe Reader. The format is maintained through any common platform (Windows, Macintosh, or Unix). If you don't have the Adobe Reader application on your system, you can download this directly from Adobe, who make the program available FREE from their web site, with complete simple directions for your system. Just click on the "Get Acrobat" logo below.

When you access pdf pages from within a lesson, be sure to get acquainted with the menu bar and the toolbar icons. Use the "Help" pull-down menu to activate the "Show Balloons" function to help you do this. The Adobe Reader is very useful for searching, enlarging, and doing other things with the file. When you are done with the pdf pages, just "Quit" the application, or click the "Back" button on your browser.

For more tips and pointers for reading and using pdf files, see "Using Adobe Acrobat Reader"

Lesson Feedback

If you have any questions about a lesson, or run into any problems in using a lesson, please contact us. We can't always promise a prompt reply, but every effort will be made to respond with useful suggestions quickly whenever possible. Likewise, it's always good to hear positive feedback. Please share your success stories in using these lessons. We will include your comments in the WHAT''S NEW section with the next updating. To send us email, go to the TALK TO US section.

Appeal for New Lessons

As all experienced teachers know, circumstances vary from classroom to classroom (and even from class to class!). Consequently, you may find that a lesson needs a little modification to fit your situation. You might even find that a lesson seems to evolve into a somewhat different lesson, effectively addressing the same or even a different but related purpose. You might have even developed your own lesson which effectively teaches one of the ENSI concepts. In any of these cases, you are invited to share your modification or new creation with other teachers by adding it to the ENSI web site. If you want to do this, please:

  • type it up in the format used on this site (see next section),
  • avoid using copyrighted material directly,
  • indicate its source (as far as you know); the author(s) will be given proper credit,
  • and email it to the ENSI webmaster.

The ENSI faculty will review it according to the criteria used in selecting all other lessons on the site. Every effort will be made to add your lesson or mini-lesson to the collection, especially if it deals well with a topic for which we have few good lessons (now THAT''S something for you to work on!). Get creative! To send us email, go to the TALK TO US section.

Lesson Structures

 There are two main lesson structures used on this site:

  • Main Lessons, and
  • Mini-Lessons

MAIN LESSONS: Each main lesson is organized into eight sections, most of which are comprised of two or more parts, as shown below:


 Main Title, Sub-Title,
and most recent author(s)

 Major Topic
and Sub-Topic
 SYNOPSIS: A brief summary of the lesson
----Principal Concept
----Associated Concepts
----Assessable Objectives
----Student Handouts & Worksheets, and Keys to worksheets
----Teaching Strategy & Preparation
----Procedures (Detailed steps for teacher and students)
----Assessment & Evaluation
----Extensions & Variations
----Other Resources
 ATTRIBUTIONS: Known source(s) of the lesson and this version.
----Often in pdf (Adobe Acrobat) format, ready for copying.

 MINI-LESSONS: These are brief "Idea Pages": ways to use existing lessons (commercial and teacher-made) and selected articles, to implement some of the objectives of this program. Their structure is simply an abbreviated version of the Main Lesson organization, usually only a page or two in length, in the following format:


Main Title, Sub-Title,
and most recent author(s)

 Major Topic
and Sub-Topic
----Student Handouts & Worksheets, and Keys to worksheets
----Teaching Strategy & Preparation
ATTRIBUTIONS: Known source(s) of the lesson and this version.
----Often in pdf (Adobe Acrobat) format, ready for copying.


Questions have been raised about how these lessons are sequenced. "When is it best to present Nature of Science lessons?" "When is it best to introduce Evolution lessons?" "Which lessons work best?" "Which lessons should you start with?" "In what sequence do the lessons work best?"

As you may well imagine, there is no one correct or even best answer to any of these questions. We all teach differently, based on experience, style, and the teaching environment. However, we will try to address some of the questions in a general way.

The ENSI program clearly encourages teachers to begin the course with (or use very early in the course) lessons in the Nature of Science, just to set the tone (the true nature of science, in contrast with some popular misconceptions). Then, throughout the course, recycle elements of the nature of science in the context of other topics.

Also very early in the course, according to the ENSI philosophy, the unifying topic of Evolution should be introduced, preferably with lessons on human evolution. And again, wherever evolution provides clear insight and "connectedness" in other topics of the course, be sure to point this out (or, even better, ask you students to do that).

Examples of workable sequences will be offered in our section on Teaching Units. For starters, you will find the sequence used by the webmaster to open his Biology course, and introduce the topics of the the nature of science and evolution, with special emphasis on presenting human evolution as a captivating way to enter into an overview of evolution in general. Many of the lessons used are on this web site.

REQUEST FOR UNIT PLANS: If you have a particular approach or sequence of lessons which has worked well for you (using ENSI lessons), share it with your colleagues. Send (email) it to us, and we will add it to the site.

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