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 Evolution: Constant Change
and Common Threads

HHMI Lecture Series, December 2005

Link to This Lecture on Free DVDs


Reviewed by Larry Flammer, ENSI webmaster

This excellent resource is available on a set of DVDs free for the asking from the Howard Hughes Medical Institute (HHMI). It consists mainly of four lectures given by two biologists to an audience of high school students. If they are simply shown "as is" without suitable preparation, discussion and pacing, the "talking heads" format by itself may not be terribly inspiring, and may not be well received by many students. However, the content and sequence is excellent. There are many excellent animations and video clips that teachers can easily access and use in their own presentations.

The opening 20 minutes provides an excellent introduction to the general topic of evolution and Charles Darwin's life and contribution to the subject. Several aspects are presented that most students probably wouldn't know, and presents Darwin as a compassionate and caring man who was truly insightful and productive. I would highly recommend showing this segment in your introduction to evolution. Parts of the lectures that follow generally assume that students have completed some work in genetics. If you introduce evolution early in your course, you could show those segments later, as excellent examples of the application of genetics to questions about evolution.

Examples used extensively in the lectures include studies of the artificial selection of corn from its ancestral teosinte, selective breeding studies in dogs, pocket mouse selection, and stickleback fish evolution. There are also informative segments on Drosophila selection, human evolution, and butterfly development.

An important feature is the easy access to the animations and video clips taken from the lectures. For example, the Fossil Documentary clip (in the DVD Features) gives students a real sense of the techniques and frustrations in hunting fossils, even by experts! It would serve as an excellent preliminary to the Video Clip on the Fossil Record of Stickleback Evolution. This dramatic animation shows a detailed recap of the changes in a stickleback fish feature over some 25,000 years, based on the analysis of the fossils from the annual layers (varves) in a fossil lake bed in Nevada, including the appearance and timing of intermediate forms. An excellent ENSI lesson to use in conjunction with this is "Varve Dating" by John Banister-Marx.. Go to item #7 in the "Other Resources" in that lesson for detailed references to those clips. You might also want to check out the excellent ENSI lesson on "The Case of the Threespine Stickleback."

The second lecture does an excellent job of showing how some questions raised by our studies of life are nicely explained by evolution, in contrast to traditional explanations. This would fit in nicely with the "Evolution Solution" approach to teaching biology: students are given experiences early in the course that raise questions, and evolution is introduced as the only explanation that consistently and completely answers those questions. This provides a most useful course theme into which the entire course can be integrated and unified. Click on "Evolution Solution" to see this paper.

Lecturer Sean Carroll, is one of the growing number of scientists doing work in the area of EvoDevo (Evolutionary Embryology), and is also the author of a recent book Endless Forms Most Beautiful, where he clearly describes how the genetics of development has helped us to understand how easily and quickly diverse forms can arise in populations. Key ideas and examples from this new field are included in these HHMI lectures, including excellent animations that show how genetic switches work, and the role of genetic tool boxes, e.g., the hox genes. Another animation on toolkit genes can be found on the PBS-Evolution site.
A useful lesson can be found in the Teachers' Domain.

AN INVITATION: It would be very helpful if we had a few more interactive activities that students could work on in the context of these lectures. If any of you do develop such activities, and they work well in your classes, please share with the ENSI network. Suggestion: read Carroll's book and study the HHMI videos. Look for questions asked... and answered. Develop interactive lessons that enable students to discover those answers, or figure them out, given appropriate information.

The final lecture includes a segment on human evolution, which would be helpful if used in conjunction with the ever popular ENSI "Skulls" lab and the "Chronology Lab".

On the second disk, in addition to interesting comments by the lecturers, you will find a provocative and engaging discussion, with students and panel, about the religious concerns about evolution. This could make for an interesting prompt for such a discussion in your class, if you feel it would help to clarify the distinctions between religious and scientific ways of knowing, and contribute to greater understanding of the nature of science and awareness of popular misconceptions. There is a serious need for students to learn exactly the limits of science: what it IS and what it is NOT. That's why a solid introduction to the nature of science early in your course is so very important. If you do that, then getting into the contrived conflict between evolution and certain religious ideas may not even be necessary.

On the HHMI web page, you will find links to the Virtual Transgenic Fly Lab, and a segment on the evolution of the Y chromosome, with animation. Likewise, you can find more segments in other HHMI programs that could be used to illustrate the evolution of other structures and processes.

A Second HHMI Evolution DVD is now available (free), featuring a most engaging lecture by scientist and biology textbok author Ken Miller. He effectively discusses "intelligent design" and other religious concerns related to evolution and science. Lots of material that could be useful to share in your classroom.

ADDITIONAL TEACHING MATERIALS
Find additonal teaching materials and references at Teaching Macroevolution and Evo-Devo on the ENSI site.