The definition of the word EVOLUTION is
“to change over time”.
• Individual organisms DO NOT evolve.
• Populations of organisms do.
• Population – a group of individuals belonging to the
same species, occupying the same given area
• They exhibit variation among the individual members,
but they also hold certain morphological, physiological,
and behavioral traits in common.
Evolution
How can a species change over time?
What happens to make a change occur?
(Talk this over with your neighbor- I want to hear
several ideas you have on how changes can occur)
• Biologists have observed two different types
of evolution.
DIVERSITY
• Divergent evolution is when species that are similar
and closely related become increasingly different from
each other. THEY DIVERGE
This is also called Adaptive Radiation….because it has to do with ADAPTING to
different environments and RADIATING out into different species.
DIVERSITY
• When distantly-related organisms evolve to become
more similar, it is called convergent evolution.
• Convergent evolution occurs when unrelated
species occupy similar environments in different
parts of the world.
A pattern of evolution in which distantly related
organisms evolve similar traits is called
convergent evolution.
This occurs when species that do not have a recent common ancestor occupy
similar environments in different parts of the world.
They evolve to look similarly, but they may be
genetically unrelated.
Many times convergent evolution is the reason for
analogous structures too.