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posted on July 24, 2016 | Teaching and Learning
Frank Spear and the Pea Seeds

 

In late
August 1967,
I was a brand-new
high school biology teacher in the suburbs
of San Francisco, east of Berkeley in Concord. 
That
part of California, and most of the state, actually, has a
Mediterranean climate.  Cool, wet winters alternate with
hot, dry summers. No rain falls from April to September,
and between that and the heat, the grass and herbs
that make that part of the world so green in the
winter and spring are dead by May
and the hills stand golden all
summer long:

Golden California.

I hear spring can come overnight
in Michigan, Minnesota, and Manitoba,
and sometimes I try to imagine it.

Seasons
don’t snap into place
like that in California, and they
don’t slide smoothly from one
to the next, either. 

Storms build up
and storms die back in
fits and starts. 

First thing each
fall is a spitty little rainstorm
that hardly gets the windshield wet.
Then it dries back out and it gets
hot again, all in one day.  It
might not rain again
for weeks.

Storms get
longer and wetter and
fair weather gets cooler and shorter
til everyone knows it is cool and wet and
winter. It is as green as Ireland by New Year and as green
as the Shire by March.
Then it dries back
up again and dies.

That first
autumn,
I noticed something
wonderful. 
One morning on the way to
work a couple of days after a little rainstorm, the
golden slopes of Mt. Diablo were tinged subtly with the
lightest shade of green, just a tinge and almost so faint
I couldn’t see it.  A
day or two later it was gone and the
mountain was golden again. 
The same thing happened
after the next storm and the next and the next, til dry
spells were cool and short enough and wet spells
long and wet enough for the world to look
and feel like winter
and I thought
about that often for a year.

The golden parts
of the mountain were annual
grasses and herbs that die every year,
so the green couldn’t have been
them “greening up”

They died months
earlier and only their seeds remained
,
I thought, so what could the greenings be
but seeds germinating after
each rainstorms? 

If hills turned
green from germination
and then turned gold again, plants that
germinated early must have died before they really
got started.  Only seeds that germinate late enough
in autumn would survive to reproduce.
But which
seeds germinated early and died and
w
hich were late enough
to live? 

Every
time it rained next
fall, on the best day to do it, I took
my classes outside to the parking lot and
asked them to look up at Mt. Diablo.  A
bout
140 high school kids looked at one mountain
on several occasions approaching winter.
Each time, I asked the same question:
do you notice
anything different
about Mt. Diablo today? 

Nobody noticed
anything after the first
storm. 
We went back inside
with no discussion and
rumors circulated
about my
sanity.

After the
next storm, a few kids
noticed a subtle shift in color,
but it wasn’t dramatic enough to
capture their imagination.

It was
a start, though,
and
we went outside again each
day to check the color. 
They
noticed the hills turning gold again,
but few 10th graders found any-
thing there to wonder about. 

I managed
to lead them to realize
that the green must come from
seeds germinating and talked a
few kids into bicycle expedition
into the hills to check that
assumption. 

Their notes,
sketches, and collections
of dried-up seedlings confirmed my
suspicions about the biology.  But I didn’t
know enough about stimulating creative
thought to take it much farther with
students without flat-out telling
them what I thought.

I learned mountains
about teenagers’ knowledge of the
natural world, and about their reasoning
power.  But not enough about how they imagine
things to lead them to ask and answer questions
like that by themselves. 

Fortunately
for both of us, Frank
Spear solved my problem
and showed me how
it’s done.

 

In addition to
three 10th grade courses, I
also taught two sections of a second
year biology course for science
‘keeners’ who
had taken biology in 10th grade and had already
taken or were concurrently taking upper level math,
chemistry, and physics and it was
entirely a research
course after the first few weeks.
This story describes
one of those investigations and
Teaching for
Creativity in Science
  describes another.

Most of those
older students were no
more interested in the colour of Mt.
Diablo than younger students were,
and though
they appreciated the tooth-and-claw meat of
who lived or died, they got little farther in their
thinking about the
greening of the mountain
than the 10th graders. 
I found that
both fascinating and challenging.

One morning
a day or two after a minor
storm, Frank Spear came to see me
before class. 
He asked to take a chair to
the roof to sit and think about Mt. Diablo.
After cautioning him not to break his neck
or disturb the physics class that would be
below him, I gave Frank permission to
spend his class time on the roof, and
the same thing happened all week.
The next time Frank came to
class he confronted
me.

“I know which
seeds germinate after it rains!”
I asked what he thought and he replied,
confidently,
that it was the little ones. Only the
smallest seeds get enough water to germinate after
little storms.  B
ig seeds soak up a little bit, but not enough
to germinate.  It takes more water because they’re bigger.
That lets big seeds dry up again until it rains enough
to let them soak up enough water.  The little
ones already germinated and died.

The little seeds die
and the big seeds live. 
I thought
that was wonderful,
and the first thing I did
was  congratulate him.  “
That’s a fantastic idea”,
I said, “but what makes you so sure it’s right
?”  “Well
it makes sense, doesn’t it?”  “Sure it makes sense, Frank.
It makes a lot of sense and maybe it’s right, b
ut making
sense doesn’t make it right.  B
esides, you haven’t told
me what makes you think small seeds get enough
water and big ones don’t. 
What’s
so special about size?”

Frank didn’t
appreciate my conservatism
but he kept working on his argument,
and presented more and more of it each
day.  Each day I acknowledged his progress,
then pointed out problems that still made
it difficult for me to fully accept his
story.  Or believe it.

Gradually,
day by day
and with
a great deal of frustration on
Frank’s part at my stubbornness but
nothing but delight on mine, Frank Spear
discovered for himself what he needed to include
for me to give in, cry uncle, and congratulate him
on a job well done and done.
It took a lot, and the key
was for him to realize that the relationship  between
the surface area and volume of anything, regardless
of shape, depends  on its size. Based on that insight,
Frank eventually produced a formal version
of his hypothesis that he could and did
test experimentally. 
It took
him a while.

As we went
along, I freely acknowledged
the elegance, the completeness, and the
generality of Frank’s argument and praised
him liberally for each of his accomplishments.
I was very proud of him and let him know it.
But as impressive as his argument became
I made sure he knew it didn’t convince
me and wouldn’t convince
me until it did.

Rather than
explaining differences between
deductive and inductive reasoning
and getting him to test his hypothesis
experimentally, I just worried aloud
about his argument and let him
figure it out.  Not surprisingly,
that frustrated Frank
even more. 

Each day
in class he either sat by
himself, apparently brooding, or
asked to go to the library. 
His knowledge
of
seeds, weather, geography, membranes,
germination, and soils expanded enormously
but Frank remained frustrated I wouldn’t admit
his formal argument solved the problem he had
started with. 
One day, Frank came to see me
before school started. “
What are you doing
during your prep period?'” “
I don’t know
yet, Frank, but I
think I’ll be doing
something with you.  What
do you need
?”

I want
you to take me to the
garden store to buy some pea seeds.
I need round peas too, not those wrinkled
ones
Mendel studied. If I use wrinkled seeds I
can’t estimate their surface area and you’ll say
my experiment doesn’t answer my question. 
To
see whether small seeds germinate faster than
big ones my seeds all have to be the same
shape, right? 
If I use all round seeds I
can calculate their surface area
from their diameter and
you won’t complain.

I met Frank
at my car and on the way
to the store Frank outlined his method.
I suggested a few things to make it easier,
we bought every round seed in the store and
Frank gradually refined his approach over the
next couple of weeks.  He planned to use a ruler
to measure diameters, for example, so I
t
old him about calipers, then got him
permission to weigh them into
size classes at a research
station next door.

Frank’s final
experimental protocol,
like the hypothesis it tested, was
born with pain
and frustration on
Frank’s part
because of my
stubbornness. It was
beautiful!

One especially
difficult issue for Frank
was what to record; how to tell
whether seeds had germinated or not.
After much reading about seeds and germi-
nation, he realized
that seeds swell as they absorb
water.  By some point they’ve swollen so much that
the membrane covering them ruptures.  Once that
happens, Frank reasoned, plants must either
grow or die and there’s no going back.
He
couldn’t find direct support for that
idea, but I was thrilled with his
reasoning and agreed with
his definition of
germination.

Frank planned
to record when each seed
germinated, using splitting seed coats
to indicate when it happened.  But I worried
that since Frank didn’t know how long it takes pea
seeds to germinate and he had many other things to
do including sleep, m
aybe there’s a way to estimate
germination time rather than measure it, so he would
not have to watch all day and night. 
Frank quickly
realized that if he held the seeds against the sides
of test tubes with tightly rolled paper towels,
he could observe at regular intervals
and record how many seed
coats had ruptured
by then. 

That
way, Frank convinced me,
it wouldn’t affect the outcome
of his experiment if some seed coats
ruptured on the side away from the glass,
as long as that error was the same for all
treatments.
He planned to observe tubes
each hour around the clock until the last
seed germinated. 
“The last seed?” I
worried.
“What if some of your
seeds are dead
?”

We compromised
on some arbitrary proportion and
he went ahead.  In each of a set of test
tubes
arranged randomly in test tube racks, Frank Spear
arranged 5 seeds from the same weight class in each
test tube, and he had enough seeds to replicate each
of ten weight classes several times over.  He filled
tubes with water at Time Zero then carried
them around with him and checked every
hour of the day and night for
germinated seeds.

Just as his
formal argument predicted
would happen, small seeds germinated
first. 
Frank and I were ecstatic.


I made the
original observation and
asked a question that got him started,
but Frank Spear went through the complete
cycle of scientific discovery in his work. 
He began
with an observation from a complex real world
situation, pondered it in simple terms, thought
of a testable way to explain it, tested the idea
experimentally, analyzed the results,
returned to the observation and
interpreted it in light
of that analysis.

That’s what
professional research
scientists do for a living. Depending
on their discipline, it might take years
for them to complete even one cycle
but
Frank Spear did it in one part of
one course in high school.
That’s incredible!

Along the way,
Frank learned a lot about
competition within and among
species, evolution of reproductive strate-
gies,
plant anatomy and physiology, weather
and climate, community ecology,
genetics, and
other things,
including a great deal about what
Frank Spear himself could accomplish in his life.
I taught Frank little of what he learned about
any of those things.
What I taught him, if I
taught him anything, was
how to think
like a scientist,
communicate with
scientists
, and tell the truth
about what he did and
didn’t know
.

Unless students
have at least some experience
of going through this cycle, on their own
or in collaboration with peers,
they might learn
a lot of informationand remember it for a while,
but without their own personal experience
of learning like that
they won’t learn
much about science
as a way
of learning things
.

What a pity for anyone to miss out
on that. I’m glad I didn’t.


It was no mere
coincidence that Frank Spear
and the Pea Seeds unfolded as it did.
A little over a year earlier, after an experience
I had in the same room during my interview for
the job, I promised myself to let students learn
for themselves as much as possible
instead of
teaching them. 
I wrote about that experi-
ence in
Secrets of Silence in the
Classroom
and told about it in
Stories about Stories.

You can find many
manifestations of this principle in
my stories in all categories.


Edited January 2019.

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