Bone Talk

One of my early childhood students found an object on walk with his class on a path through the woods near our school.  He brought it to me wondering, “Is this a stone or is it a bone?” 

We looked at it together.  From the shape and heft, it was certainly a bone.  “Where did you find it,” I asked, and he told me about a spot on the trail, “near some deer tracks.” 

“Which do you think it is,” I asked him, “bone or stone?”  “I think it’s a bone,” he said after a few second hopefully.  “I think so too.  Feel the weight.  It’s too light for a stone of the same size. Also, look at those little holes all over it.  Bone is like that.  What kind of bone do you think it is?  Where in an animal’s body do you think this came from?” I queried.

He looked puzzled.  “Is it a bone from a skull?”  He looked doubtful.  The bone was a short, thick oval, with some oddly shaped projections.  “Is it from a leg?  Or a foot?” I continued. 

He clearly didn’t think so, but was quiet for a while.  “What about from a bone from the back, from a spinal column?”  He was still quiet.  “What if this bone had lots of others like it piled on top of it?”  “Yes,” he said eagerly, ‘it could be a backbone.”  “Yes, and then nerves would run down this hole in the center and the shape would let the animal bend in many ways,” I offered.

 “What kind of animal?” he asked.  “What do you think?” I asked.  Quiet again.  Both of us.  I waited.  After the right amount of time, I asked, “Big animal or small animal?”

“Big animal,” he enthused right away.  “What kind of big animals live in those woods?” I went on.  “Deer!  Do you think it’s a deer?” he asked eagerly.  “Yes, I do” I said.  “Let’s look at it with the magnifier.”

“How old is it?  Did the deer just go down there and die?” he wondered.  We looked at the discolored bone, dirty beige with some white patches.  “Old,” he guessed.  “I think so too,” I agreed. 

The white patches puzzled me until I looked closely with the magnifier, seeing many fine, evenly spaced vertical scratches in the recessed white patches.   “Why is some of the bone brownish and some white?” I asked.  Quiet. “Maybe some of the bone was in the dirt and some was sticking out and it got rubbed away?” he offered.  “Maybe, but look at where the patches are.  How would you place the bone in the dirt so only those special places stuck out?” I asked.  Quiet.  We could both see no way to place the bone in that way in the dirt.  I pointed out the scratches and we co-evolved the idea of a small scavenger gnawing on the deer bones lying on the trail.

“Wow!” he exclaimed.  Now we had a fuller story line from a bit of bone lying alongside a woodland trail.  “That’s an interesting bone,” I said.  “I think you should share this with the class.  And show it to your parents tonight.”  It would be a good conversation at home.  I love teaching science.

Real vs Imaginary

On March 17^th, before a session with early childhood students, the teachers mentioned St. Patrick’s Day.  In this discussion, several children mentioned leprechauns.  From the very lively discussion, the existence of leprechauns seemed implicit.  I asked, “Are leprechauns real or imaginary?”  It quickly became clear that many PK'ers believe that leprechauns are real.  Deciding to follow a critical thinking path, rather than a doctrinaire, rain-on-your-parade path, I asked what evidence they had that leprechauns were real.  I gave the example that we could demonstrate that horses were real animals because we could find a live horse and touch it.  Could we do the same for leprechauns?

Whenever a discussion like this comes up I feel it is important to proceed gently.  As a parent, I cherish my daughter’s early delight in imaginary animals and imaginary friends, as well as her continued enjoyment of science fiction and science fantasy.  As a science teacher, I do look for ways to begin to build scientific habits of mind and critical thinking.  Early childhood is not too early.  As students grow and develop, they need to be able to distinguish between what is real and what is not.  I always try to do this without being a killjoy.  I need to read some about what developmental psychologists and other child development experts say about how children acquire this ability to differentiate real from not real. 

I have had this discussion before with a different group of early childhood students and it is clear that the composition of the group and their previous experiences make a difference.  Several students in this group had been in one or more preschools where the teachers had told them about leprechauns as real beings and had helped them set leprechaun “traps”.  Several students reported that these traps had actually caught leprechauns, though no one could give a description of one.  Had this teacher or these teachers actually intended to foster the idea that leprechauns were real?  Or was this how their young minds processed a fun story and a whimsical activity?  I will revisit “real vs. imaginary” with this group.  I need to plan how to do this with sensitivity and in a way that builds their critical thinking rather than satisfying my needs to tell them how the world “really” is.

You Can See a Lot Just by Observing

Yogi Berra's famous malapropism takes on new meaning in learning and teaching science. Science really does begin with observation. Some recent work with a pre-kindergarten class that had become fascinated with fungus illustrated this for me. Their classroom teacher and I were taking them on a walk through a wooded area near their classroom to look more closely at the woodrat nests we had seen on an earlier visit. Looking for woodrat nests is a bit like looking for green cars; at first you don't see any, but once you start thinking about them, you see them everywhere.

There is an even earlier step when you first learn to recognize an object, such as a woodrat nest or a fungus. This too is a learning process. Usually when viewing something new, such as the woods, people see an undifferentiated blur. Then when someone points something out to you, shows you how that this thing, this rock, this nest, this lichen, can be separated from the blurry mass, it springs into reality. You can now see it where before you could not.

As we walked, one of the children pointed out a lichen on a tree and asked, "What's this?" We all looked at it and told the children it was a lichen. We told them that lichen was pretty interesting as it is a double organism, a partnership between an alga, which makes food, and a fungus, which provides the protective structure or home for the partnership. Most of them has seen algae on a pond and almost everyone knew about mushrooms, a very familiar type of fungus. Now that lichen had an image, a name, and some information connected with it, they started spotting lichen everywhere on our walk and wherever they went in the following days.

This strand of our curriculum emerged as the children began to see other organisms that resembled the lichen they had first seen. Some of these are lichen, too, we told them, but of a different kind. The first one we had seen was a foliose lichen. They were now looking at crustose lichen, which lie flat on a bare rock or tree trunk. Once you start seeing two types of something, you have a deeper concept or what the organism is, as well as what it is not. This is also the start of classification and taxonomy.

Crustose lichen. source:  Wikipedia

The PK class was on fire and the study deepened and broadened as they started looking at mushrooms as well and learning about the different types of mushrooms. The classroom teacher found nature books about mushrooms, as well as stories about mushrooms. We found that a husband-and-wife team of naturalists in our community that specialized in mushrooms and we learned the terms mycology and mycologists. They walked with the class in the woods and took the class much deeper into the study of mushrooms: how they get food, how they propagate, how they fit into the larger ecosystem. They class then delved into learning the parts of mushrooms and how these parts work together, structure and function. We dissected mushrooms in class and looked at them closely with our eyes and hand lenses.  We looked at slices of the mushrooms under microscopes, taking slices from caps, gills, stem, and any other part that looked interesting to them.

Observation is fundamental to all science.  All science begins with observation and it had long been the first among the process skills of science.  I like a great deal about the new Next Generation Science Standards (NGSS), but I am puzzled why the framers left observation out of the new Practices of Science and Engineering.  I've heard it said that they just presumed that observation was so obvious that it needed no mention.  I would agree that it should be obvious, but so is Asking Questions, which made the cut.  So is Analyzing and Interpreting Data.  So I am still puzzled.   Meanwhile, I continue to teach my students to observe the world around them.  Woodrat nests and lichen are good starting points.