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A Mini-Lesson



Video Notes Worksheet


Larry Flammer
ENSI Webmaster


Variations and Natural Selection
 NEW ARTICLE: Common Misconceptions about Natural Selection. Go to our Evolution Introduction page, scroll down to bottom of page for "A Few Very Common Misconceptions" and a link to the excellent article that exposes a number of widely held misconceptions, with clues for correcting them (June 2009).


Video showing recent field work on a twenty two-year study of finch beaks on a small island in the Galapagos, showing natural selection clearly operating in the wild. Includes vignettes of Darwin's life, and the Grant family working and living on the island. Excellent video. Video-notes worksheet helps to guide viewing for students, and facilitates subsequent discussion.


1. Traits are usually favored by natural selection only when they result in more reproductively successful offspring.

2. Natural selection can be observed in nature to produce significant changes in the characteristics of a species.

3. Elements of the environment play a clear role in giving direction to selection.


 Video: "What Darwin Never Saw", from the PBS series "The New Explorers", with Bill Kurtis. This program aired on Public Television in October, 1995. Call 1-312-951-5700 (Kurtis Productions) to order the video ($20); ask for Rebecca Kelly. Or, write to Kurtis Productions (attention Rebecca), 400 W. Erie Street, Suite 500, Chicago, IL, 60610. Send check for $20 payable to Kurtis Productions.
Click HERE for excellent YouTube version (46')


 (see end of lesson for the formatted handouts).

Copy of "Video Notes" for each student.




This 50 minute video could be shown as a very engaging introduction to evolution in general, or to natural selection in particular. Or, it could be shown as part of your wrap up and summary of your work on natural selection.

When I use the film, we have already studied the nature of science, so my students should know the difference between a theory and a hypothesis, and that a theory is a concept in which we have a high degree of confidence, due to considerable supporting evidence, so to say "only a theory" reveals a popular misuse of the word, incorrectly suggesting that it is just a tenuous idea.

I also will have covered a brief overview on the diversity of life and the formal elements of classification.

In my introduction to evolution, I make a point of going over several things that evolution is NOT, primarily to dispel some of the popular myths people often assume about evolution (see my unit outline in the outline section on this site). I will have clearly distinguished between the "origin of life" and the "origin of species", and have pointed out that biological evolution is NOT about the origin of life, but it IS about the origin of species. There is a popular confusion about these two ideas, assuming they are the same, no doubt stemming from the biblical account that all life, in all its present forms (species) was created at one point in time. With the clear evidence that many different forms have come and gone over long periods of time, evolution attempts to account for this, leaving the formation (creation?, beginning?, origin?) of first life as a separate issue.

I will also have introduced the class to Charles Darwin, his life and contributions, using film, slides, text, and bulletin board, all as part of my formal introduction, early in the course, to the general ideas of evolution and natural selection.

Against this backdrop, the video offers an excellent opportunity for students to see scientists at work in the field (as opposed to a "lab"), testing ideas, and showing how careful observations can reveal telling patterns. It also conveys some of the "humanness" of scientists, ordinary people, with families, doing extraordinary things. Students can identify with this, and perhaps be inspired to do this kind of work. [NOTE: In the original version of this film, a few minutes were devoted to the two young daughters of the Grants who lived with their parents on the island at different times, and practiced violin, did homework, etc. Sadly, that segment was not included in the YouTube version linked to here. For that reason, I would encourage getting the Kurtis Productions (original) version if possible.]

VIDEO NOTES: I have found that students tend to pay closer attention to a video if they are looking for particular bits of important or unusual information, as long as there are not too many little "bits", and they have substantial time to just watch and enjoy. "Video Notes" also provide a convenient vehicle to clarify certain important points presented in the video, but possibly done too quickly or not as clearly as you would like. Finally, the notes are useful for initiating discussion after the video, especially if this must be put off to the next day (since the film takes about a period just to watch).

I often ask students to add on the back any questions that come to mind ("always watch with a questioning attitude"), or points to discuss. In addition, I may ask them to "rate" the video, and to indicate what was most memorable. I collect the papers at end of video, and quickly check them over, looking for their comments on the back. The next day, I use some of their questions or comments to initiate discussion.

WARNING ALERT: Showing a film that's more than 10-15 minutes could be deadly, but using the Film Notes helps students to focus and maintain interest. In middle school (and even high school), it might be helpful to stop the video from time to time to pose a relevant question (especially directed to students who seem disinterested), like "What was wrong with two things the narrator (Bill Kurtis) just said?" Or "Why was that last comment by Peter Grant so important?" This breaks up the film, wakes up students who have zoned out, and helps make students more alert and attentive to content.

A key to the "Video Notes" follows the worksheet below.

I highly recommend that you read the popular book which covers this study: The Beak of the Finch by Jonathan Weiner (Knopf, 1994, $25), a Pulitzer Prize winning book about the Grants and their work with the finches, as featured in the video. This should be in your school library, as well. For any students wanting more of the "meat" of the study, encourage them to read it, too.



An excellent alternative lesson, built around the Grants' finch sudy, with data,, a lesson, and a key, can be found on the PBS-Evolution site.

For a good overview of Natural Selection, and an alert to some common misconceptions about it, take a look at the handy summary: "Comparing Evolution Mechanisms" near the bottom of the "Introduction to Evolution" page. Darwin's and Lamarck's essential elements are compared, and a few common misconceptions are clarified. Scroll down to download the PDF file of this information.

More Online Lessons and Related Resources:
Biointeractive's interactive materials on Galapagos Finches, with data to analyze, speciation, etc. (excellent)
Teach Evolution and Make it Relevant (causes of evolution)
Clipbirds Teacher.doc : Natural Selection of Acquired traits and Allopatric Speciation
Bird Beak Buffet: My Science Box: (Several sub categories (see right hand column on the site)
Finch Beak Data Sheet (Document graphic)
What Darwin Never Saw (video)
Case Study (Original Data from the Grants' Study) -
Prentice Hall
PBS Learning Media: Finch Beak Data and other materials on finch beak studies
Evolution (PBS short video: Evolving Ideas: "How does evolution really work?")

Other Excellent Videos on Darwin and the Galapagos:
What Darwin Didn't Know (1h 28')
What Darwin Never Knew (NOVA, 1h 54') (see below)
Charles Darwin and the Tree of Life (Attenborough 1 hr.)

Excellent: What Darwin Never Knew (NOVA: 1h 54')
YouTube version (1h 37'). First aired: 12/21/2011
Program Description
(Program not available for streaming.) Earth teems with a staggering variety of animals, including 9,000 kinds of birds, 28,000 types of fish, and more than 350,000 species of beetles. What explains this explosion of living creatures—1.4 million different species discovered so far, with perhaps another 50 million to go? The source of life's endless forms was a profound mystery until Charles Darwin brought forth his revolutionary idea of natural selection. But Darwin's radical insights raised as many questions as they answered. What actually drives evolution and turns one species into another? To what degree do different animals rely on the same genetic toolkit? What makes us uniquely human? And how did we evolve?
"What Darwin Never Knew" offers answers to riddles that Darwin couldn't explain. Breakthroughs in a brand-new science nicknamed "evo devo", are linking the enigmas of evolution to another of nature's great mysteries, the development of the embryo. NOVA takes viewers on a journey from the Galapagos Islands to the Arctic, and from the explosion of animal forms half a billion years ago to the research labs of today. Scientists are finally beginning to crack nature's biggest secrets at the genetic level. The results are confirming the brilliance of Darwin's insights while revealing clues to life's breathtaking diversity in ways the great naturalist could scarcely have imagined.
For each Related Link pictured below the main picture...
Support Materials:
... Background Essay
... Discussion Questions
Educational Standards
... National Standards
... NGSS


Anoles Evolution Virtual Lab from HHMI BioInteractive
BioInteractive Short Films: (one DVD): Lizards in Evo Tree; Beak of the Finch; Making of a Theory
BioInteractive Virtual Lab Series (one DVD): Lizard Evolution Lab; Stickleback Evolution Lab; et al
BioInteractive Sheets: Teacher Materials and Student Worksheets for...
Four modules, two deal with analog comparisons (morphologies), two with measurement, calculations and graphing. Also, DNA comparisons, leading to likely phylogeny; looking for trends, patterns.
Measure leg lengths, toe lengths, tail lengths. Ecomorphs compared on each island. Questions raised, tested, and analyzed for most likely explanation. Leads to evidence for convergent evolution.
Excellent tutorial about how to do Think-Pair-Share
ENSI lesson: Island Bioeography: A Lizard Tale
ENSI lesson: Case of the Threespine Stickleback

Science Daily article of interest; Support for controversial Darwin theory of 'jump dispersal' [e.g. "Rafting"] Science Daily, October 1, 2014.
" How did this lizard's ancestors arrive on the Caribbean island where they live? A new study affirms a long-controversial view that some organisms, like this Grand Cayman blue-throated anole, may have crossed oceans in creative ways." " A new computational method, published in the journal Systematic Biology, tested two competing theories about how species came to live where they do and found strong evidence for jump dispersal [e.g., rafting], especially for island species."

See BioInteractive for many more resources:
Many excellent resources, e.g., Short Films, Virtual Labs, Animations, Click & Learn and more resources for teaching Evolution, DNA, Geobiology, Infectious Disease

The Origin of Species: The Beak of the Finch
HHMI BioInteractive: Blumenrath
[Use this instead of the ENSI Oat Seed Lab]
Excellent (Meets several expectations in NGSS, AP Bio, and IB, all spelled out in Teacher Materials)
Four parts (With Short Film, Teacher Materials and Student Worksheets/Handouts):
Beaks As Tools: Selective Advantage in Changing Environments
Evolution in Action: Graphing and Statistics
Evolution in Action: Statistical Analysis (t-Test)
Sorting Finch Species: Click and Learn (includes analytical comparisons of finch sounds)

PBS Learning Media - California
Training Trees (Tutorial for making phylogenetic trees)


Some of the ideas in this lesson 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.

1. Original Source: Larry Flammer, 11/95

2. Reviewed / Edited by: Martin Nickels, Craig Nelson, Jean Beard: 12/15/97

3. Edited / Revised for website by L. Flammer 4/16/99
Updated Nov., 2014


 The following is a useful worksheet for students to complete while watching the video, to help focus and direct their viewing. A KEY follows, for teacher use, or for use by students as a self-check. PDF VERSION CAN BE ACCESSED AT BOTTOM OF PAGE.

 Name___________________________________ S.N._____ Date_________ Per.____


VIDEO NOTES: "What Darwin Never Saw" (The New Explorers series, w/ Bill Kurtis)


1. In the first few minutes of the film, the narrator, Bill Kurtis, uses two phrases which are technically incorrect in their biological context, and you should recognize this from our course so far. How should they have been worded to be more accurate?:

A: He said: "...the finches held the secret to the origin of life." He should have said:

"...the finches held the secret to the origin of ___________"


B: He said: "...but it was only a theory." He should have said: "...but it was.._______________________"


2. What did the Grants do when they went ashore on the island to be sure nothing was brought onto the island from the "outside world" (no insects or other creatures which might disrupt the natural habitat on this isolated island)?


3. What is the main enemy of the of the finches on Daphne Major Island? _______________


4. What is the finch on Daphne which digs into cactus blossoms? __________finch


5. What major biological process have the Grants seen TWICE during their 22 years of studying the islands?


6. In what year did the Grants first come to the island? _________


7. The three questions they were trying to answer by studying the finches were:

a. Do species compete?

b. Why are some populations so variable?

c. ________________________________


8. Why was Daphne Island chosen? ______________________


9. One species of finch was G. scandens (Cactus Finch). The other species was G. fortis. What is its common name:


10 How many finches did they find and band on the island? __________


11. When binoculars are reversed, what can they be used for? _______________


12. Your choice: some interesting facts given about Darwin in his experiences on the Beagle, tortoises, etc:




13. What did the Grants find when it didn't rain for 18 months?_______________________________


14. They found that natural selection operates under.._______________ conditions.


15. Birds with ____________ beaks tended to survive the drought best. Why?



16. All but about ________% of all species which have ever existed are extinct now, [so what % are extinct?___]


17. The Grants measured the beaks of the next-generation birds (from those which survived the drought). What was the size of those beaks (compared to the average size before)?


18. What surprising conclusion did this observation provide good evidence for?



19. Which finches survived best after it rained so heavily (for 8 months)?______________ Why?


1. A) "...species"; B) "...a possible hypothesis"

2. rinsed everything in seawater

3. weather (not owls)

4. Cactus

5. natural selection (or evolution???)

6. 1973

7. c) How are species formed?

8. simple, small (100 acres)

9. Medium Ground Finch (Geospiza fortis) [see The American Biology Teacher, April, 1993, p.243 presenting this and other examples of natural selection]

10. about 1000 finches

11. microscope

12. [open] [show some Wedgewood pottery, if you can]

13. 400-500 dead finches found (mostly G. fortis)

14. stressful (specifically draught conditions in this case)

15. large; They can break into large seeds that smaller-beaked finches can't open.

16. 1% [so 99% extinct!]

17. larger (3-4% deeper)

18. Evolution proceeds much more rapidly than Darwin suspected.

19. smaller finches



Video Notes: "What Darwin Never Saw", plus Key


 The following pages are in Adobe Acrobat pdf format in order to maintain their intended layout for easy printing of handouts. Only a "thumbnail" reduced size image of the first page is showing (if more than one page is in that file). For enlarging and copying, (and seeing other pages in that file), you will need to download the free Acrobat Reader from Adobe (unless it's already installed in your system). Then just click on the blue file name above, below, or next to the first page. You may see the "Acrobat Exchange" (Reader application) loading, then the pages will display. You might need to shift-click and drag the lower left corner of the page to enlarge it, or click the magnifying glass on the menu bar.

If this doesn't seem to work, you might need to load and/or enable the PDFViewer plug-in by following one of these protocols:

For Netscape Communicator: EDIT>Preferences>Navigator>Applications (then scroll down to "Portable Document Format (PDFViewer)", click on it, then click OK; if it's not there, click on "New", and add it in).

For Netscape Navigator: OPTIONS>General Preferences>Helpers (scroll to check for PDF on list, add it if it isn't, then click OK to activate it.

For other browsers, or problems with this, check with your browser tech support, Adobe tech support, or, in dire frustration, e-mail me. If nothing else, I will mail you hard copy of the formatted pages desired.

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