Global Warming: An Introduction to the Research and the Nature of Science

Since November, 2006, I have been enjoying a series in Natural History Magazine entitled “Samplings: The Warming Earth”. (scroll down the page to find the “Samplings” specific to “The Warming Earth.”) The articles are actually very concise summaries of research published in professional journals. The samplings are representative of a wide range of research. For example, there are summaries of research that predict possible effects of climate change (as “Pipefish Baby Boom”) to identification of contributing factors (“Don’t Blame the Sun”), to how climate change may be tracked (“Reading the Leaves”). Here’s a sample from one of this month’s (May 2007) “Samplings:”

Oysters on the half shell are considered a delicacy, but what about mussels on the three-quarter shell? A new study shows that human emissions of carbon dioxide (CO2) could reduce bivalves’ ability to build their shells by as much as 25 percent.
In addition to warming the Earth, excessive CO2 is making the oceans more acidic, which decreases the concentration of dissolved carbonate in seawater. Without carbonate for building their shells, numerous minute organisms—including corals and species of phytoplankton and zooplankton—are showing alarming signs of distress. Now Frédéric Gazeau, a marine biologist at the Netherlands Institute of Ecology in Yerseke, and several colleagues have shown that the phenomenon propagates up the food chain.
In the laboratory, Gazeau exposed mussels and oysters to water with various levels of CO2 for periods of two hours, measuring the water’s average pH and the change in its alkalinity, which is proportional to its concentration of carbonate. From alkalinity levels he calculated the mollusks’ rate of shell construction, or calcification. Sure enough, the higher the water’s CO2 concentration and the lower its pH, the slower the mollusks’ calcification.
If atmospheric CO2 reaches the levels expected by 2100, Gazeau predicts the calcification of oyster shells could decline by 10 percent and that of mussel shells by a quarter. As the declines in calcification affect the development of juvenile shellfish, and as adults become more vulnerable to predation, both aquaculture and marine ecosystems are likely to change. Gazeau stresses that his findings are preliminary; he measured only short-term responses to high CO2 and low pH. But his next experiment will test their responses over several months. (Gazeau, F., C. Quiblier, J. M. Jansen, J. Gattuso, J. J. Middelburg, and C. H. R. Heip [2007], “Impact of elevated CO2 on shellfish calcification,” Geophysical Research Letters 34, L07603, doi:10.1029/2006GL028554)

Links: Netherlands Institute of Ecology (NIOO)
Laboratoire d’Océographie de Villefranche (LOV)

—Rebecca Kessler

Recently in class a student commented that he didn’t “believe” in global warming. When asked why, he responded that he didn’t see how scientists could study such a phenomenon. This student comment followed upon the heels of a conversation with a colleague in which we lamented the difficulty of providing students with insights into the nature of science. It occurred to me that perhaps the Natural History “Samplings” might be a way in which I could simultaneously introduce my students to some of the research on global warming and provide insights into “how scientists know what they know”.

This turned out to be a very simple, but effective assignment. My students were asked to read a specific number of summaries (depending on the grade they wanted to earn). For each article they selected to read they needed to identify three components: the research question or problem; the kind of data collected and/or an explanation of how the data was collected (through field experiment, computer modeling, etc); and the conclusion of the research. After reading as many summaries as they committed themselves to, they were asked to write a reflective summary in which they explained what they learned about global warming or about how scientists work.

Based on what my students wrote (9th grade biology) and on a follow-up class discussion, I found this simple assignment to be successful. In addition, it had the benefit of piquing their interest in global warming!

Sandy Collins
Biology (9th grade)
West Junior High School
Lawrence, KS 66044
scollins@usd497.org

KABT at KATS

I’m posting this info for Randy who is unable to attend and present at the 2007 KATS KAMP KABT thread. Randy was going to share a number of resources that he has tried out and found effective in his biotech courses and in AP Biology that deal with microarrays. These include:

Web animations such as this one from Malcolm Campbell at Davidson (click on the screen shot):

Microarray animation

Virtual Labs like this one from the Genetic Science Learning Center in Utah (click on the screen shot):

Virtual Lab

Select the BEOP link for teaching materials. (Student materials and answers)

BEOP Microarray paper by Carolyn A. Zanta, UIUC-HHMI Biotechnology Education and Outreach Program (BEOP)
www.life.uiuc.edu/hughes/footlocker:

And finally two papers:

Microarrays made simple: “DNA chips” paper activity, by Betsy Barnard from the online component of the American Biology Teacher, March, 2006. You’ll need to be an NABT member to access this link.

DNA Microarray Wet Lab Simulation Brings Genomics into the High School Curriculum, A. Malcolm Campbell, Carolyn A. Zanta, Laurie, J. Heyer, Ben Kittinger, Katleen M. Babric and Leslie Adler, CBE–Life Science Education, vol. 5, 332-339, Winter 2006

BW

Analogies in Biology teaching

One of the essential tools in a biology teacher’s tool kit is the analogy. Analogies help students to form their own, personal biological concepts within a more familiar context. Analogies are truly a double-edged sword, (using an analogy to describe the use of analogy.) On one hand they help students to acquire and build their knowledge and understanding but on the other hand they invariably lead to the acquisition of some level of misconception. This negative aspect of analogy is particularly true when working with students just beginning their journeys (another analogy.) Teaching with analogies is a balancing affair. A teacher needs to present the analogy to begin the discussion but also follow up with a discussion of the limits of the analogy.

For a teacher just finding a starting analogy can be a challenge. Here’s two:

Today, I came across a great analogy describing the mechanism of cell receptors and flu viral infection at Effect Measure blog.

Earlier I came across one of the better analogies I’ve seen for describing the developmental toolkit at PZ Meyer’s Pharyngula blog.

BW

ScienceBlogs

KABTer’s,

A growing resources for keeping up with biology is a site known as ScienceBlogs. This site, sponsored by a new science magazine, Seed, brings bloggers with a science theme into one site. It has grown to be a tremendous resource. However, I doubt that it will pass school district filters since these bloggers cover more than just science topics–they cover politics, biology controversies and religion as well. and often they do not censor their own variety of speech. Each of the bloggers have some kind of expertise and had successful blogs before they joined ScienceBlogs.

So how does a biology teacher make use of this site. One quick and easy step would be to check in each day and click on the “Biology” link in the left column. This would take you to the most recent posts with a specific biology focus. Personally, I simply click on the “Last 24 hours” link to view all posts over the last 24 hours. Remember, these folks are publishing their opinions and informed understanding of new research, controversy and such. Not one of the bloggers would expect you to agree with them all the time, nor would they expect you to take their word as the last word on a subject. Read these entries with a critical eye and view this as the process of science. You’ll be able to get in on some of the controversies that you didn’t know existed in biology.

Finally, start with the Science Basics list. This list was a challenge that went out to this community to try and cover just the basic concepts in a field. I haven’t read all of them but some are quite good and some I don’t find so good. Overall, though, I think it is a great place to beef up your own understanding of basic science so that you can pass it on to your students.
BW

NABT/ABT Online Resource

NABT

KABTer’s,

If you are a member of NABT you may not be aware of an exciting new online resource the American Biology Teacher. The American Biology Teacher is now a kind of hybrid journal–part in print and part online. All of the print articles from ABT are available online in pdf format. In addition there are additional articles that are available only online. ABT simply has more articles submitted than can be printed and so there is a back-log for printing which sometimes means an unacceptable delay before publication. Authors now have a choice. If they choose the online-only publication mode, their article is generally shared sooner than a print version would be. This increases the number of articles in each journal for NABT members–a win-win situation. Here’s a listing of February’s 3 additional online articles:

ABT Online

Inquiry & Investigations

Filthy Flies? Experiments To Test Flies as Vectors of Bacterial Disease

Are flies really as dirty as we think? Students create and test hypotheses about the ability of flies to transmit bacteria.

Julie J. Shaffer Kasey Jo Warner W. Wyatt Hoback

French Fries, Dialysis Tubing & Computer Models: Teaching Diffusion & Osmosis Through Inquiry & Modeling

A mini-unit where students design their own investigations and use computer modeling to visualize diffusion and osmosis.

Patricia Meis Friedrichsen Amy Pallant

How-To-Do-It

Use of the Photoactic Ability of a Bacterium To Teach the Genetic Principles of Random Mutagenesis & Mutant Screening

An easy mutagenesis procedure using a versatile photosynthetic bacterium helps students learn about the power of mutant screens.

Neena Din Terry H. Bird James E. Berleman

Log-on to the NABT website and check it out.

BW

btw,

If you are not a member, please consider joining–you will find NABT to be a valuable part of your professional life.