Download Evolution - Downtown Magnets High School

An Intro to the Theory
Biology Standard 7
What is Evolution?
• Change of an organism
over time.
• Modern orgs have
descended from past
orgs.
• Charles Darwin and
Alfred Wallace proposed
how evolution works.
Evolution in Action
Darwin Bio
• English!
• Great grandpa Erasmus
helped develop his theory.
• Journeyed on HMS Beagle
in 1831-1836…collected
animal/plant specimens.
• World was biodiverse:
many diff. types of species.
Galapagos Creatures
Species
•Considered
separate species if they
cannot interbreed
•Same species create viable offspring
NO Dog-Cat
Babies!
YES Panda
Babies!
Charles Darwin 1809-1882
Wallace vs. Darwin
• Both independently came up with the theory
of natural selection to describe how evolution
works.
• Published findings at Linnean Society of
London in 1858.
• B/c Darwin was from a rich background, we
only hear Darwin’s name.
Am I Hot or Not?
Alfred Wallace
Charles Darwin
On the Origin of Species
• Book published by
Darwin in 1859.
• Modern descent:
(orgs change in
response to
environment).
• No DNA Talk!
Also Talked About…
• Evolution =
SLOW!
• If an org. has
traits that allow
them to survive
and reproduce,
they are termed
fit (Darwinian
fitness).
So… Am I
Fit??
Not Fit…Extinct!
Dodo
Not Fit…Extinct!
Passenger
Pigeon
Not Fit…Extinct!
Stellar Sea
Cow
Adaptation
• Trait that allow organisms to be better
suited to their environment.
• Orgs cannot choose to adapt  naturally
through environmental pressures.
Adaptation Importance
• Org adapts to environment 
SURVIVES (passes on traits to offspring
(kids)).
• Org. cannot adapt DIES!!
• Darwin termed this natural selection.