convey knowledge. If K–12 students demonstrate difficulties with
this metaphor (Meisel, 2010) and with interpreting trees, it may
be valuable to get back to the “root” of the problem with the pattern, the tree itself, and represent it with varying designs and versions. For this reason, phylogenetic trees are represented in the
workbook as trees with leaves and branches and also as “implied”
trees. Understanding how phylogenetic trees and data are used by
scientists does not necessarily mean that students understand the
relationship on a macroevolutionary scale or understand evolution itself. It may be beneficial to discuss how Darwin arrived at
the tree metaphor from his immersion in the natural world, how
the immense diversity of living things that occupied his days
shaped his thinking. This reveals to students how culture, exposure to nature, and history shape the way we think. Broad perspectives on the past help reframe life processes that are
typically viewed through increasingly narrow lenses. Even graduate students, biologists, and other professionals struggle to accurately interpret evolutionary relationships, so the cartooning and
storytelling approach isn’t just for schoolchildren but has potential uses at higher levels of knowledge.
Whole-Brain Thinking & Evolutionary
It has been observed that the way we teach and our focus on cognitive function favor the left hemisphere. From a very early age, we are
predominantly centered on verbal, symbolic, and sequential experiences (Sylwester, 1995). Even formulas like Hardy-Weinberg give
the illusion that evolution is a step-by-step process, a sequenced formula. In the last decade, though, biologists have begun to recognize
that despite knowledge being conveyed in a linear manner, actual
living systems and biological processes are anything but simple linear progressions (Capra, 2005). Introducing a little fantasy can go
a long way in teaching biology – and with tardigrades, nature has
already produced something stranger than fiction. Fantasy literature
can provide children the opportunity to engage the whole brain. As
fantasy demands visualization, it immediately engages the right
hemisphere (Aigner, 2007). The study of such literature can jar students out of linear thinking, help them synthesize ideas, and encourage them to think holistically (Moore, 2009). Such “right-brain”
thinking can have tremendous benefits when applied to scales and
complexities on Earth that are problematic to convey in texts. When
comparing picture storybooks that employ interdependent storytelling, distinct categories emerge (Agosto, 1999). One of these categories is transformation. When knowledge is confusing – perceived as
chaotic, disorganized, and lacking synthesis – stories provide a
framework within which students can think transitionally while
building a solid view of evolution and ecology, macro-processes,
and micro-process concomitantly.
Tardigrades make intriguing characters to read about. They also
make excellent characters for stories about evolutionary processes
because they give students insights into qualities such as cryptobiosis, horizontal gene transfer, phylogenies, and adaptive radiation.
Reading the story line; practicing the drawing of movement, shape,
and detail; and coloring the workbook allows students to enter a
cartoon world of an organism prior to labs, lectures, or database
searches. These hands-on practices and perspectives allow students
to incubate the complexities and work through activities at their
own pace, employing their individual learning styles and becoming
intimate with an organism that can prompt an immediate interest
in evolution and phylogenetic tree-thinking.
Plan for “Trundlers in Time”
1. Lead students on a nature walk around any wooded area,
finding mosses or lichens. With or without a lab, give an
introductory talk on Tardigrada (30 minutes).
2. Present a short PowerPoint with various microscopic
images of water bears (light field, dark field, scanning electron microscopy) for students to see what they really look
like, including images of desiccated “tun” or cryptobiotic
states (15 minutes).
3. Draw or show a phylogenetic tree of invertebrates, with the
unresolved relationship of Tardigrada.
4.Do wnload and print the workbook (http://www.timetree.
org/public/data/pdf/JoeTardigrada.pdf). It can be printed
on regular white paper for coloring purposes.
5. If this is a unit on evolution, pose the question “How did water
bears become so specialized for extreme environments?”
6. Introduce the concepts of natural selection, divergence,
extinction, speciation, niche, and phylogeny (45 minutes).
7. Hand out the workbook. Give students time to read and
color. As a second assignment or continuation, ask them
to look at the page with the tardigrade morphing into different niches. Ask them to choose a niche and draw what that
new species might look like, and then finish coloring the
8. Ask students to explain their drawings (“Why does it look
9. If there is time for a lab, see “How to Find Tardigrades
(Water Bears) in Your Own Backyard” at https://microcos-
10. Have students perform the lab and observe organisms
under the microscope, even if there are no tardigrades.
Using the drawing exercises, ask them to draw any moving
invertebrates they observe and describe their similarities to
and differences from tardigrades.
11. Have students do an easy TimeTree database exercise to
familiarize them with geological times and divergences.
12. Have students turn in their drawings and workbook. The
workbook should be assessed on the level of completion.
Rather than a rubric, it is easier to “eyeball” the work, to see
if students applied the drawing/noticing instructions when
looking over their work. You could also go through the drawing with them on the board by drawing the tardigrade, the
onychophorans, and the annelids as well as the ornamental
qualities of the eggs.
13. Give students a short quiz on terms studied, asking for