Page 22 - The Dinosaur Book and Other Wonders of the Prehistoric World (DK-Smithsonian)

Evolution and

Introduction extinction

Fossils reveal how life has changed over time. This
was not fully understood until the 19th century, when
fossils became important evidence supporting the
theory of evolution by natural selection. Developed
primarily by English scientist Charles Darwin, this

theory showed that the individuals in a species vary
in their ability to cope with the hardships of life—
some survive and breed, while others do not. As a
result, species gradually change over time as they
adapt to the changing world. New species evolve, and
older ones may die out completely, becoming extinct.

Fossil evidence Bony tail ❯ At first sight, this
When the first fossil of Archaeopteryx 150-million-year-old fossil of an
showing wing feathers was discovered Archaeopteryx looks very like a living
in 1861, it was seen as powerful bird, with broad, feathered wings. But it
evidence in favor of the theory had a long, bony tail like an extinct
that living things evolve over time.
dinosaur. This combination of features
does not exist in any modern animal.

Natural selection
Every animal is different
from its parents. This
natural variation produces
individuals with different
strengths and weaknesses,
so some are more likely
to survive. An insect with
more effective camouflage
than its cousins will be
more likely to evade hungry
birds, breed, and pass on
its advantages to its young,
Meanwhile, its less well
camouflaged relatives
may die out.

The jagged edges and
pattern of lines add to the leaf
insect’s superb camouflage.
20 Leaf insect Archaeopteryx

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