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Evolution
Chapter 16.1-16.2
I. Introduction
A. Evolution – any change in a population
over time.
1. Micro – small changes within a species.
2. Macro – change into a new species.
I. Introduction (cont.)
B. Evolution is a THEORY based on
scientific evidence. The basic ideas are:
Differences exist within the genes of a
population.
In an environment, some individuals are better
suited to survive and have more offspring.
Helpful traits are passed on.
Fossil evidence
II. Adaptation
A. Adaptation – the accumulation of
characteristics that improve an organisms
ability to survive and reproduce.
B. Animals adapt to the demands of their
environment.
C. Structural Adaptations – bodily
characteristics that best suit an organism for
survival
II. Adaptation (cont.)
D. Behavioral Adaptations: organisms
behave in a certain way in order to survive
in their environment. (example: birds fly
south for the winter).
III. Natural Selection
A. Natural Selection– an attempt to
provide an explanation for observations.
B. The organisms best suited for the
environment will survive and pass on their
traits to their offspring. Organisms NOT
suited will eventually die off and become
extinct.