Reflections — Fossils 1

In 2010, I was nominated for the Presidential Award for Excellence in Math and Science Teaching—a prestigious honor for math and science teachers in the United States. The rigorous application process provided me with an excellent opportunity to reflect deeply on my classroom practice. Although I was not selected as a finalist, I value my experience in the process. Over the next three blog posts, I would like to share some of what I wrote for my application, which centered around a geologic unit on fossils.

The PAEMST application requires a written narrative on several dimensions of outstanding teaching, including the following areas:

• Dimension 1: Mastery of Science Content
• Dimension 2: Instructional Methods and Strategies
• Dimension 3: Effective Use of Student Assessments

In this entry, I would like to share Dimension 1, Mastery of Science Content...

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There are three essential questions to guide the study of fossils:

1. What are fossils? 
2. How do fossils form? 
3. What can fossils tell us about past life? 

Planet Earth is billions of years old, and during its long history a diversity of life has evolved. Fossils are the remains of living organisms preserved in the geologic record through burial, and they provide valuable evidence for this long Earth history. Students need fundamental understanding of the geologic processes that led to fossil formation, the types of fossils that form as a result, and the types of clues that are found within the fossils that can be used to interpret past history.

Image courtesy of MorgueFile

Three main types of fossils—body, trace, and replacement—form over time periods of thousands to millions of years. Each type of fossil has unique physical characteristics and clues to help us infer past Earth history. Because fossils are found mainly within sedimentary rocks, it is essential that students understand the constructive and destructive processes involved in sedimentary rock formation, which ultimately lead to the preservation of once-living organisms.

Information about the environments in which fossilized organisms lived can be inferred from fossil clues when students rigorously apply the process of science. Making careful, detailed observations using different scientific tools (such as hand lenses and microscopes), asking a variety of probing “interview” questions about each fossil, referencing fossil identification guides and charts, and collaborating with other student scientists are all key to interpreting fossil clues in a non-biased, open-minded manner to unlock the information about their past environments.

Fossil evidence helps us infer geologic, environmental, and biological changes through time. By examining fossils and reconstructing the story they tell, students fine tune their “process of science” skills and develop a better understanding of the 3.5+ billion-year life history of planet Earth. Specifically, students engage in making detailed observations of fossils and asking questions in order to infer information about the geologic past.Students will apply what they learned during fossil identification to a future plate tectonics research project. The skills and knowledge developed in this lesson will be applied to understanding spatial and temporal changes of Earth’s tectonic plates—fossil evidence gives us clues that Earth’s crustal plates move and that continents were once connected.

This particular lesson on fossils contributes to the “Six Facets of Understanding”—a lesson planning tool I use to develop deep, engaging learning activities—as outlined below: 

• Explanation: Students address the following conceptual questions: 1) What are fossils? 2) What the different types of fossils? 3) How do fossils form? 4) How can we infer information about past environments from examining fossils?
• Interpretation: Students observe and “interview” fossils to determine the physical characteristics of organisms and infer the past environment in which they lived.
• Perspective: Students make connections between life and conditions on planet Earth today and life and conditions during geologic eras and periods of the past.
• Self-Knowledge: Students may inquire about or begin to assemble their own fossil collection, or seek opportunities to learn more about fossils (for example, museum visits).
• Empathy: Students consider why geologists study fossils and develop a better understanding about the difficulties involved in fossil interpretation and reconstruction.
• Application: Students engage as fossil scientists and create their own fossil identification cards that show physical characteristics and inferred information about past environments.

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A variety of misconceptions and misunderstandings about fossils can arise in the science classroom. Here is a summary:

All rocks contain fossils.

Fossils are found mainly in sedimentary rocks. For an organism to become a fossil, a protective layer of sediment, such as sand or mud, must quickly cover up its remains. Otherwise, the remains are likely to be eaten, to decompose, or to be destroyed before fossilization can occur. Probing questions to ask students: 

• Why don’t we find fossils inside rocks like granite, basalt, gneiss, or schist?
• Why do we find fossils inside rocks like sandstone, shale, and slate?

Fossils are actual pieces of dead animals and plants, rather than preserved impressions of the original organisms. 

During the fossilization process, the living remains of organisms decay and are replaced by minerals, leaving behind an impression of the original organism. Exceptions to this include insects that are fully preserved in fossilized tree sap (amber). However, most organisms are preserved in an altered state during the fossilization process. Probing questions to ask students: 

• Petrified wood, a fossil, is not wood anymore. What happened to the wood?
• If you have a fossil shell or leaf imprint, what happened to the original organism?

All living organisms leave behind fossils, and the fossil record is complete. 

Hard structures such as bones, teeth, shells, and exoskeletons are more likely to be preserved during the fossilization process than soft body materials such as tissues, organs, and/or hair/feathers, which decay more readily. It is estimated that only 1% to 3% of organisms have fossilized and/or been described. While our fossil record keeps growing as we explore more and more of Earth’s crust, we will never have a 100% fossil record because not all species leave behind fossils and not all fossils can ever be found or recovered. Probing questions to ask students: 

• Why do scientists keep looking for fossils, even today?
• Why don’t we find fully preserved, fully intact organisms (like dinosaurs) buried in the ground? Why do we usually just find skeletons, bones, teeth, etc.?
• When an organism dies, what parts decay and what parts are preserved, and why? 

Geologic time is short, and fossils are relatively young. 

Geologic time is vast. The fossilization process, which occurs during the sedimentary rock formation process, can take thousands and millions of years to occur. Various dating techniques allow scientists to accurately determine the ages of rocks and fossils. Fossils are thousands, millions, and in some cases, billions of years old. Probing questions to ask students: 

• How do you think fossilized seashells got to the top of the Rocky Mountains?
• What does finding fossilized seashells in the Rocky Mountains tell us about the past?

Few species have gone extinct during Earth’s history. 

More than 99% of all species (which number in the millions) that ever lived on planet Earth have gone extinct. The fossil record leaves us evidence of species that are no longer alive and what the environments in which they lived were like. Probing questions to ask students: 

• Have you ever seen an organism like this (show pictures of extinct organisms)?
• What happened to these organisms?

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References

• Boulder Valley School District, 2009 Middle Level Earth and Space Science Curriculum Essentials Document, Earth and Space Science Essential Questions
• Ganse, J., Geology Unit, 8th Grade Earth Science, Fossil and Geologic Time
• Marshak, S., Earth: Portrait of a Planet (Third Edition), W.W. Norton & Company, 2008
• Murck, B. and Skinner, B., Geology Today: Understanding Our Planet, John Wiley & Sons, Inc., 1999
• USGS Education, Schoolyard Geology, Fossils

Endless Cycles

Cycles are a recurring theme in Earth science. A continuous spatial and temporal flow of matter and energy circulates through overlapping "spheres" of the Earth system, moving from reservoir to reservoir via a variety of physical and chemical processes. In our Earth science class, we see parallels among the different Earth system cycles: in the atmosphere, it's the carbon cycle; in the hydrosphere, it's the water cycle; and in the geosphere, it's the rock cycle.

Image courtesy of Microsoft Clipart

Resources abound for learning about the various Earth system cycles. Here are a few of my favorites:

Atmosphere—Carbon Cycle

NPR It's All About Carbon
NPR's offbeat science guy, Robert Krulwich, hosts five entertaining and informative animation shorts that explore the role of carbon in Earth's atmosphere.

POET Carbon Cycle, How It Works
NOAA's POET provides a set of hands-on, inquiry-based activities, one of which has students simulate the movement of carbon through the carbon cycle.

NOAA Carbon Cycle
NOAA Education Resources provides a comprehensive collection of scientific resources (data, activities, background information, and more) about the carbon cycle.

Hydrosphere—Water Cycle

NOAA JetStream, What a Cycle!
This site includes links to high quality water cycle posters, and a lesson that includes constructing a water cycle wheel that can be used for classroom discussion and simulations.

NASA Molecule Max
Part of NASA's Global Climate Change program, this video produced by NASA's JPL provides a tutorial on how the water cycle works and how NASA studies it with the latest space technology.

NASA Earth Observatory, The Water Cycle
The Water Cycle is one of the featured articles in NASA's Earth Observatory that provides a complete overview of Earth's water cycle, including data, explanation of processes, and discussion of observed trends.

Geosphere—Rock Cycle

Learner Rock Cycle Interactive
The Annenberg Foundation's Learner website includes a detailed interactive for students to explore the many aspects of the rock cycle.

AMEP Rocks
For a great source of bulk rocks (and minerals), visit American Educational Products to build your own classroom collection for students to investigate. Their Investigations in Science — Earth Science guide includes one of my favorite classroom activities for rock identification, "What Rock Is It?"

Onion We May Slowly Be Running Out of Rocks
The Onion provides a humorous article about the current state of rocks on planet Earth and our need to protect and conserve them. A fun, alternative reading activity...

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If you have any favorites, please share...

A Few Good Science Quotes

Image courtesy of Microsoft Clipart

As a voracious reader, I love a pithy and memorable quote, especially when it comes from the world of science. Here are a few excellent and eminently ponderable science quotes for the Earth Science classroom:

"Some are weatherwise. Some are otherwise."
—Benjamin Franklin

"If we would know the oceans, we must go to the oceans."
—John Delaney, Oceanographer

"We learn geology the morning after the earthquake."
—Ralph Waldo Emerson

"If it disagrees with experiment, it's wrong."
—Richard Feynman, Physicist

"If you wish to make an apple pie from scratch, you must first invent the universe."
—Carl Sagan, Astronomer

"The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'"
—Isaac Asimov, Author

"If you're scientifically literate, the world looks very different to you, and that understanding empowers you..."
—Neil deGrasse Tyson, Astrophysicist

"Science literacy is vaccine against charlatans of the world that would exploit your ignorance of the forces of nature."
—Neil deGrasse Tyson, Astrophysicist

"The most incomprehensible thing about the world is that it is comprehensible."
—Albert Einstein

"Somewhere, something incredible is waiting to be known..."
—Carl Sagan, Astronomer

Feel free to share your favorites...

Snow Day!

Image courtesy of SnowCrystals.com

We had a snow day this week. All day before the storm, students (and other teachers) would ask me about the storm and whether or not we'd have the next day off. As the resident weather geek, I was happy to oblige their questions and share the salient data. There are a plethora of weather tools available on the internet these days, but I always turn to a few favorites that are well-suited for scientists and educators alike.

The Weather Channel offers the cleanest, best-looking weather maps on the internet. I use these maps in the classroom to help students learn about weather symbols and patterns. Multiple maps are easy to save and stack inside an application like Apple Keynote or Microsoft PowerPoint to create a beautiful weather map slide show.

Weather Underground is the finest source of in-depth weather information for the weather enthusiast. One-stop-shopping for maps, local weather data and forecasts, radar images and animations, severe weather alerts, and more. I particularly like their email notification services, which always keep me informed of the latest weather watches and warnings. For the classroom, wunderground's radar animations (which can be downloaded and saved) are an excellent way to help students understand patterns associated with precipitation, atmospheric circulation, and severe weather.

For official information about weather watches and warnings, NOAA's National Weather Service is the place to be. Only the National Weather Service can issue official watches and warnings for severe weather events; it is therefore crucial to understand what these watches and warnings mean so that appropriate preparations can be made. Each local National Weather Service office also offers local storm reports, which catalog snowfall totals, wind speeds and wind damages, hail sizes, and other significant weather events.

To keep track of the clouds, NOAA's Aviation Weather Center offers some great satellite imagery tools. Their "loop-big" satellite animations are excellent for helping students better understand cloud motion, cloud formation, and atmospheric circulation. Additionally, the satellite imagery offers water vapor views that helps students think about the flow of invisible water vapor in Earth's atmosphere.

For the pure science geeks, access to the raw data is important. Again, NOAA's Aviation Weather Center is the place to go. It offers access to up-to-the-minute METAR data from weather stations all across the United States. METARs typically include the basic meteorological variables such as temperature, dew point, wind speed and direction, barometric pressure, cloud cover, precipitation, etc. I use this resource in the classroom to help students understand how weather data is collected, recorded, and reported.

Tired of the current weather and wanting to know when the next big snowstorm is coming? Turn to Unisys Weather to view and analyze short-, medium-, and long-range information from computer weather models. I enjoy viewing the GFSx 500 mb height and SLP loop, which shows the progression of large-scale weather patterns and trends across the US in a colorful 10-day animation.

Finally, for your artistic enjoyment, check out beautiful photographs of snow crystals at SnowCrystals.com — the site all about snow crystals and snowflakes. With its stunning images of snow crystals, The Secret Life of a Snowflake is a fine addition to the science classroom or library book shelf.

Now, get outside and enjoy the snow day!

Science Research Projects

The "research project." When I was in school, I (vaguely) remember doing research projects which mostly consisted of, "Pick a topic, write a paper, and hope for the best."  Given today's wide-open internet, what should a 21st-century research project look like? Unlimited choice and freedom can be daunting to many students, but overly-rigid parameters can stifle creativity. Somewhere in between is a healthy balance where students can explore a research topic in-depth and express their learning in a variety of creative ways.

Image credit: MorgueFile

Over the years, my biannual research projects have evolved to help students both efficiently leverage the latest resources on the internet and maximize their research potential. The "research paper" I produced umpteen years ago in school pales in comparison to the "power projects" my students create today.

While I believe strongly in giving my students choice in expressing their learning, I have found that completely open-ended choice can lead to less-than-excellent results. Students are more apt to achieve excellence when provided with guidelines, structures, and checkpoints along the way. It's my job to facilitate learning, and the research project provides an opportunity for me to help students really kick it up a notch.

For our ocean research project, I've established the following structures and guidelines:

Essential and Supporting Questions
Rather than instruct students to "pick a topic" at the beginning of the project, we spend time brainstorming and writing both essential and supporting questions. An essential question usually begins with either "why" or "how" and is not something that can be easily answered. Supporting questions usually start with "who/what/when/where," are more factual in nature, and serve as the anchor questions around which students conduct their research and write their final product.

To create these questions, I first have students start writing a stream of questions without stopping to edit or judge the quality of the questions. The goal is to get the ideas flowing. Once students have written 20 to 30 questions, they may then start to edit, sort, and condense these questions until they have one essential research question and a minimum of ten supporting questions. These supporting questions provide the keywords and ideas around which students organize their note system, conduct their research, and assemble their final product—a brochure or a comic book.

Organized Note System

At the beginning of the project, we have a discussion about taking notes efficiently and brainstorm various systems for note-taking, such as index cards, sticky notes, outlines, graphical webs, etc. As part of their project registration (via Google Forms), students must indicate what type of organized note system they will be using for the project, and I periodically check to see that students are using their system.

Primary and Secondary Sources 

Students are expected to use primary and secondary science sources for their research, which includes edited materials in our school library as well as various scientific websites that I have curated. During our initial discussions about the project, we talk extensively about the importance of using primary and secondary science sources, such as NASA Oceanography, NOAA National Ocean Service, Office of Naval Research Oceanography, and sites derived from them. Wikipedia is acceptable, as long as it it used as a starting point only. Blind, open-ended searches using large search engines like Google are discouraged, and use of "anybody can answer this question" websites (like eHow and answers.com) are prohibited.

The key to success here is being an active curator—I set up a web page for our project which provides students links to quality resources, reference materials, tutorials, copyright-respectful clipart, and more. If students use other sites, they must justify their choices; if we decide their choice is a quality resource, it will be added to our list of curated websites.

Structured, Yet Flexible, Format

Our ocean project is the first of two research projects we do in science each year. As such, I am slightly more structured about the written expectations of the project. Students may choose to create a brochure or a comic book, either digitally or on paper. I've narrowed down these choices over the years for a couple of reasons: 

• Left with open-ended choices, students tend to gravitate toward posters. Unfortunately, I have not been too impressed with the poster format—too often it is nothing more than cut-n-paste pictures and text randomly glued to a poster board (usually at the last minute).
• Brochures and comic books allow for more creativity from students, but also require more planning and organization. This generally leads to much higher quality.

Bibliography and Picture Credits

As scientists, we must cite the work of others, giving them credit and respecting their copyright. One aspect of this project is the formal use of bibliography and picture credits throughout the project. This can be challenging and frustrating for students who view citations as extra work and who are comfortable (and sometimes complacent) about simply cutting and pasting everything from the internet. So, at the beginning of the project we also have a discussion about the importance of using bibliographies and picture credits in research projects in order to achieve three goals:

1. provide readers with a mechanism for accessing the same material used by students, so that readers can learn more about the topic,
2. give credit to the original authors of the research materials, and
3. respect copyright and honor the creative process.

To help students with their citations, I employ both a Bibliography and Picture Credit Help Guide that I created as well as a wonderful bibliography template that I discovered online years ago. Both these tools (as well as various other digital versions) provide students with the structure to more easily and efficiently document their citations. "Make sure you have a bibliography" is not enough guidance for students.

The Journey Is as Interesting as the Destination
Research projects provide students with the opportunity to pursue their own ideas and interests, and I feel they are a vital part of science education. Open-ended research projects, while allowing for 100% freedom and creativity, tend to be too much for many students; rigid term papers are simply stifling and rather boring. A well-designed research project experience requires that teachers serve as active facilitators during the entire project (somewhat like a tour guide). It is time well spent: the experience becomes focused on asking students what they are learning, rather than struggling to keep them on task.

There's No Place Like Home(work)

NASA's Hubble Space Telescope

I've been thinking about homework (again), and the futility involved in assigning students traditional homework. Traditional homework is an externally imposed construct—it's something done "to" students, rather than something done "for" students. Traditional homework provides little in the way of intrinsic motivation, and there is no correlation between the quantity of traditional homework and academic success (see Alfie Kohn for more thoughts on homework).

Does that mean homework should be completely eliminated from schools (and life)? No. But we need to be more honest about the purpose and quality of homework — homework should enrich students' lives and support them in their quest to become lifelong learners.

So students and parents, here is your daily/monthly/yearly homework:

• Go read a book
• Go plant a tree
• Go for a walk
• Go take a picture of the sunset
• Go enjoy the weather
• Go look at Jupiter through a telescope
• Go search for the Moon in the sky
• Go visit the NASA, or NOAA, or USGS website
• Go watch Cosmos
• Go research an interest in more detail
• Go have a conversation about something you learned today
• Go pick up trash in your neighborhood
• Go volunteer
• Go think about the planet and the universe in which you live
• Go help somebody who needs you 
• Go be creative
• Go use your resources
• Go ask, "Why?"
• Go stimulate your brain, feed your curiosity, and exercise your body

Tracking Ocean Currents

NOAA Global Drifter Program: Drifter Buoy

The task is simple: "Your job is to design and draw a device to track ocean currents."

As we've been studying different aspects of ocean currents — causes, movement, etc. — it's a worthwhile endeavor to think about the instruments used to track ocean currents. A major component of How Science Works includes gathering data, and I think it is important for students to consider the myriad challenges scientists face when tasked to collect a particular type of data, such as ocean currents. I, therefore, ask students to design a device that could track ocean currents and share their design with the class (How Science Works, "publication," "discussion with colleagues," and "feedback and peer review").

The designs are always innovative, creative, thoughtful, and reasonably practical. The best part of this activity is comparing student designs with actual ocean tracking devices used by NOAA and seeing the overlap.

NOAA's Global Drifter Program utilizes drifter buoys to track ocean currents around the world:

"The modern drifter is a high-tech version of the "message in a bottle". It consists of a surface buoy and a subsurface drogue (sea anchor), attached by a long, thin tether. The buoy measures temperature and other properties, and has a transmitter to send the data to passing satellites. The drogue dominates the total area of the instrument and is centered at a depth of 15 meters beneath the sea surface."

Students are delighted to see that many of the ideas they developed in class are actually used in the drifter program. We discuss similarities and differences between their designs and NOAA's drifters to better understand the challenges and limitations involved in measuring ocean currents.

The design activity is followed up with a tracking activity that uses data from NOAA's drifter buoys to track the flow of global ocean currents. Students discover that currents in the Pacific Ocean flow in a giant, clockwise gyre at a fairly slow, but steady rate; in the process, large quantities of heat are redistributed around the planet.

It's easy for a teacher to have students just learn factual information about currents from a textbook, but that's like eating processed junk food—it provides little in the way of long-lasting nutritional value (i.e., shallow learning). US science organizations such as NOAA, NASA, and USGS provide valuable data and information that is perfect for an inquiry-based science classroom. These organizations are the primary sources of science discovery and exploration on planet Earth, and we should be leveraging their expertise in the classroom to engage our students in How Science Really Works.

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A sampling of student designs for ocean tracking devices: