Below are common ideas children in grades K-6 have about this
topic, compiled from research on children's ideas about science
(see the Session 6 Children's Ideas Bibliography).
Consider what evidence might refute this idea, and why a child
would be
likely to believe this?
1. Change in environmental conditions directly causes evolution
in the affected individuals.
In order for this idea to be substantiated, you would expect
to observe entire populations changing during the same
generation in response to a change in the environment.
For example, if a
plant population were subjected to drought conditions,
someone holding this idea might predict that all of the
individuals in
the existing population would somehow change during their
lifetime to become more drought-tolerant. Children may
begin to understand evolution as a process
that helps living things respond to environmental change
so that they can survive. Children may reason that this
has to happen
during a lifetime — that something has to be changed immediately
in the affected individuals. Thinking about evolution in
this way may be challenged once children begin to understand
evolution
as a process that occurs at a population level over many
generations. Hide
Response
2. Evolution “just happens.”
For evolution to be something that “just happens” suggests
that there is no specific mechanism for evolution nor any
predictable outcomes. Natural selection is overwhelmingly
accepted by the
scientific community as the process that best accounts
for evolution. Evolution through natural selection predicts
that, over time,
populations will become better-suited to their environments.
Many children in elementary school are likely to be acquainted
with
the term “evolution” before it becomes a part
of their science learning. Some may understand it to be
a process whereby life forms change, but without knowing
how this occurs.
They may think that the environment causes evolution, or
that change “just happens.” Once children are introduced
to natural selection, their ideas will develop further.
Activities involving artificial selection may help children
better understand
natural selection. Examples of artificial selection are
highlighted in the video for Session 5. Hide
Response
3. Species evolve because of a “grand plan.”
This is an idea that cannot be tested using scientific methods.
There is no scientifically validated evidence of a “grand
plan” for evolution, just the evidence that indicates that
species do evolve. The idea that there is a “grand plan” for
evolution is more a matter of one’s world view than a matter
of science. Children may have religious or cultural backgrounds
where this belief is held. Hide
Response
4. Evolution is goal-oriented; species evolving later in evolutionary
time are “better.”
All species that exist on Earth today can be thought of as “success
stories.” Scientists do not consider evolution to produce
successively “better” species. Whether a species
is a bacterium with a lineage that goes back billions of
years or a human being whose lineage extends back only about
2 million
years, each has evolved to be suited to its own environment
at any given time. This “fit” is considered to be
a consequence of evolution, not a goal, and given further environmental
change, any species’ survival can be challenged. Children
may have a hard time believing that a process has no goal.
As they learn about evolution, the phrase “survival of
the fittest” may promote this way of thinking. This idea
may also be a product of modern culture, where human beings are
often
portrayed as the pinnacle of evolution. Hide
Response
5. Evolution happens over a few generations.
Historically, some of the best evidence for evolution (e.g.,
the fossil record) reveals that observable change in a
species occurs over thousands or even millions of years. Many
scientists
would agree, however, that because natural selection acts
during each generation, evolution is happening at some level
throughout
a species’ evolutionary history. There are also species
that may evolve much more rapidly, under certain conditions.
Nonetheless, scientists would agree that evolution takes
longer than just a few generations to occur. In thinking about
how long an event takes, it may be hard
for children to comprehend time scales that extend more
than a few generations — their own, their parents, and
their grandparents, for example. The fossil record may
be a good place
to start to help children understand that the best evidence
for evolution suggests that it takes a very long time — possibly
hundreds, thousands, or even millions of generations — before
change is observed. Hide
Response