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Scientific Theory
A well-tested concept that
explains a wide variety of
observations
Variations
Differences between
individuals of the same
species occur because of
the shuffling of genes during
meiosis and/or because of
genetic mutations.
Competition
Since food, shelter and other
resources are limited, offspring
compete with each other to
survive. Species that go after the
same resources also compete to
survive.
Species
A group of similar
organisms that can
mate and produce
fertile offspring.
Natural Selection
Individuals that are better
adapted to their
environment are more likely
to survive and reproduce
than other members not so
well adapted
Adaptations
Any traits that help an
organism survive and
reproduce. (Beak shape
in a bird for example)
Similarities & Differences
Members of closely related
species will show many
similarities but also unique
differences, for example,
tortoises of different
Galapagos Islands.
Overproduction
Most animals and
plants produce more
offspring than can
survive.
Evolution
Species can gradually
change over many
generations to adjust to
new conditions. Natural
selection leads to
evolution.