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 Penguins
are adorable. They look very
cute when walking with faltering steps.
But, do you know they are one of the few kinds of birds that can’t
fly? They do have wings, but they can’t actually fly. Why is that?
Long ago, the ancestors of penguins could
in fact once fly. However, as they began to eat a diet consisting
almost entirely of seafood, they
found that their wings were difficult to use underwater. Therefore, they
evolved to stop flying in the air, and to start “flying” through the
ocean to find their food.
In order to adapt to a life in water,
their wings changed over time to what we call flippers.
 In addition,
interestingly, a penguin’s weight is closely related
to its flippers. According to a recent study
by the University of Texas, the density of penguin bone has
been growing over the last 35 million years. This is because
they wanted to keep their weight high to swim better. The dense bones help them to
sink and give a sturdier
flipper than a wing would. While becoming heavier, they ended their
flying days. It looks like although they
cannot fly in the air, they can fly in the water! |
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