INTRODUCTION
Organisms display variation in traits such as
body size, color, speed, and aggressiveness. Variation
is found between species and within a species. Many
traits of organisms are adaptations to their
environment. In birds, for example, there is
variability in the size and shape of the beak, or bill,
which is utilized for finding and capturing food.
Some birds have wide, thick bills used for crushing
seeds; some have short, thin bills for picking up small
prey; while others have long tubular bills for drinking
nectar from flowers.
The adaptations that we see in organisms are a
result of evolution by natural selection. Before
conducting this activity, I introduce the concepts of
adaptation, natural selection and evolution. In class,
we discuss variation in bill shape and size in
Darwin’s finches, and how this variability arose.
Then, after discussing evolution by natural selection,
the students conduct this inquiry-based activity
allowing them to simulate evolution.