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EVOLUTION
Chapter 15
Florida State Standards
Associated With Evolution
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SC.912.L.15.1- Explain how the scientific theory of
evolution is supported by the fossil record,
comparative anatomy, embryology, biogeography,
molecular biology, and observed evolutionary
change (Assessed on Biology EOC)
SC.912.L.15.10- Identify basic trends in hominid
evolution from early ancestors six million years ago to
modern humans, including brain size, jaw size,
language, and manufacture of tools (Assessed on
15.1)
SC.912.L.15.13- Describe the conditions required for
natural selection, including: overproduction of
offspring, inherited variation, and the struggle to
survive, which result in differential reproductive
success (Assessed on Biology EOC).
SC.912.L.15.14- Discuss mechanisms of evolutionary
change other than natural selection such as genetic
drift and gene flow (Assessed on 15.13).
Chapter 15- Section : Darwin’s
Theory of Evolution by Natural
Selection (p.418-p.422)
Interesting Facts about
Charles Robert Darwin
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He was born in 1809 in England.
He was one of 6 children.
He went to medical school and didn’t like it
so he did poorly.
During the time he was spending not doing
medical school things, he was gaining interest
in taxidermy, natural history, etc.
His dad sent him to become a parson (like a
priest) instead.
There he focused on providing arguments for
the existence of God through reason and
ordinary experience in nature.
Darwin’s Voyage on the HMS
Beagle
 Darwin
was invited to be
a companion and
collector for a trip on the
HMS Beagle.
 His father didn’t want him to go because
he thought it was a waste of time.
 For 5 years Darwin was on the voyage
investigating geology and making natural
history collections (rocks, fossils, plants,
animals).
The Galapagos Islands
 Galapagos
Islands are off the
Coast of South America
 Collected mockingbirds, finches
and other animals. Noticed
each island seemed to have their
own slightly different varieties of
animals.
Tortoises on different islands
Finches on different islands
The Galapagos Islands
 Darwin
suspected populations from the
mainland (South America) began to
change after reaching the Galapagos.
 Darwin hypothesized that new species
could appear gradually through small
changes in ancestral species.
 He tried to figure this out by observing
artificial selection (or selective breeding;
dogs, pigeons, etc)
Natural Selection
 Thought
about the struggle for existence
and how some individuals would be
better equipped to survive than others.
Those less equipped would die. This is the
process of natural selection.
The Four Principles of Natural
Selection
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Individuals in a population show variations (or
differences) (VARIATION- ex. Students in classroom
look different)
Variations can be inherited (passed down from
parent to offspring) (HERITABILITY-ex. You look similar
to your biological parents)
Organisms have more offspring than can survive on
available resources. (OVERPRODUCTION- ex.
Average cardinal lays 9 eggs- more than can survive)
Variations that increase reproductive success have a
greater chance of being passed on than those that
do not (REPRODUCTIVE ADVANTAGE- moth gray
color helps it blend in to tree branch)
Peppered Moth Example
Peppered moths - the peppered moths of northern
England. Originally they were light colored and
blended in with the light bark of trees. However, due to
the Industrial Revolution soot and particulate matter
covered trees making them darker, and so the light
colored moths stood out like sore thumbs. They
became easy pickings for predators. Darker colored
moths were able to avoid predation and so passed on
their genes to subsequent generations because they
were able to hang around long enough to breed. Dark
colored moths therefore survived. The whole process
was completely reversed when cleaner air returned,
allowing the trees to revert back to their pale color; the
lighter moths thrived once more.
Natural Selection
 Given
enough time, natural selection
could modify a population enough to
produce a new species.
Assignment
 Answer
Questions 1-5 from page 445.
Answers
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1. Natural selection is a mechanism for evolution.
2. Artificial selection was used to produce purebred
Chihuahuas and cocker spaniels.
3. Natural selection is a mechanism for a theory developed
by Charles Darwin.
4. Which best describes the prevailing view about the age
of the Earth and evolution before Darwin’s voyage on the
HMS Beagle?
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A. Earth and life are recent and have remained unchanged.
5. Which statement about the tortoise above would be part
of an explanation for tortoise evolution based on natural
selection?
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B. Tortoises with domed shells have more young than tortoises
with flat shells.