Download Lamarck`s Theory of Evolution

Evolution
Diversity of Life
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Evolution
“Nothing in
biology makes
sense EXCEPT
in the light of
evolution.”
Theodosius
Dobzhansky
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Charles Darwin in later years
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History of
Evolutionary
Thought
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Early Ideas On Earth’s
Organisms

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
Linnaeus – 1st to
group similar
organisms and
assign them Latin
names
Two word name
(Genus species)
Known as Binomial
nomenclature
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Charles Lyell
Proposed theory of
Uniformintarianism
 Geological processes
at uniform rates
building & wearing
down Earth’s crust
 Proposed that the
Earth was millions of
years instead of a
few thousand years
old
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
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Principles of Geology
Published by Lyell Just Before The
Beagle Set Sail & read by Darwin
 Explained Geological Processes
That Shaped The Earth
 Helped Darwin Understand Sea
Shells In The Andes Mountains At
12,000+ Feet
– Expanded Earth’s Age

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Lamarck’s Theory of
Evolution

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Jean-Baptiste Lamarck,
1809
One Of First Scientists
To Understand That
Change Occurs Over Time
Stated that Changes Are
Adaptations To
Environment acquired in
an organism’s lifetime
Said acquired changes
were passed to offspring
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Lamarck’s Theory of
Evolution
Idea called Law
of Use and
Disuse
 If a body part
were used, it
got stronger
 If body part
NOT used, it
deteriorated

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Lamarck’s Theory of
Evolution

Inheritance of Acquired
Characteristics
Proposed That By Selective Use Or
Disuse Of Organs, Organisms
Acquired Or Lost Certain Traits
During Their Lifetime
 These Traits Could Then Be Passed
On To Their Offspring
 Over Time This Led To New
Species
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
Lamarck’s Theory of
Evolution

___________-
Organisms Could
Change The Size Or
Shape Of Organs By
Using Them Or Not
Using Them
_________(muscular
arms)
 ____________from
stretching)

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Lamarck’s Theory of
Evolution

__________________________
– Traits Acquired During Ones Lifetime
Would Be Passed To Offspring
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Clipped ears of dogs could be passed to offspring!
Lamarck’s Theory of
Evolution
_____________________
 Organisms Are Continually Changing
and Acquiring Features That Help
Them Live More Successfully In
Their Environment
 Example:
____________________________
____________________________

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Lamarck’s Mistakes
 Lamarck
Did NOT Know how
traits were
_______________________
 Genes Are NOT Changed By
Activities In Life
 Change Through
_________________________
_________________________
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Charles Darwin the
Naturalist
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Voyage of the Beagle
Charles Darwin

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
Born Feb. 12, 1809
Joined Crew of HMS
Beagle, 1831
Naturalist
5 Year Voyage around
world
Avid Collector of Flora
& Fauna
Astounded By Variety
of Life
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Darwin’s Voyage of Discovery
A reconstruction of the HMS Beagle sailing off Patagonia.
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The Galapagos Islands

Small Group of Islands 1000 km
West of South America
 Very
Different ________
 Animals On Islands Unique
»________
»________
»________
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The Galapagos Islands



___________off
the coast of South
America
________________
________________
________________
Each island had long
or short neck
tortoises
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The Galapagos Islands
Finches on the islands
____________________________
 ______________________where
the available food was different
(seeds, nuts, berries, insects…)
 Finches had
______________adapted to their
_________________________

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Darwin’s Observations
& Conclusions
The Struggle for
Existence
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Voyage of the Beagle
During His Travels, Darwin
Made Numerous Observations
And Collected Evidence That
Led Him To Propose A
___________________About
The Way Life Changes Over
Time
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Darwin’s Observations

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
Patterns of
Diversity were
shown
Unique _________
in organisms
Species Not Evenly
Distributed
» Australia,
Kangaroos, but
No Rabbits
» S. America,
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Llamas
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Darwin’s Observations
 Both
Living
Organisms &
Fossils collected
 Fossils included:
»__________
»____________
____________
____________
This species NO longer existed.
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What had
happened
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Evidence for Evolution – The Fossil Record
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Definition
• _________
is the slow ,
gradual
change in a
population of
organisms
over time
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Darwin’s Observations
Left unchecked, the
_____________________
________, generation to
generation
 In nature,
_________________in
size
 Environmental
____________________

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Darwin’s Conclusion
• Production of more
individuals than can be
supported by the
environment leads to a
_________________
_________________
• Only a fraction of
offspring survive each
generation
• _________________
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Darwin’s Observations
• Individuals of a
population vary
extensively in their
characteristics with
_______________
______________.
• Much of this
variation between
individuals is
______________.
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Darwin’s Conclusion
• Individuals who
inherit
characteristics
___________are
likely to leave more
offspring than less
fit individuals
• Called
_____________
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Darwin’s
Theory
of
Evolution
•The ______________________leads
to a gradual change in a population, with
favorable characteristics accumulating
over generations _________________
•New species evolve
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Ideas That Shaped
Darwin’s Thinking
Thomas Malthus
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Population Growth
 Thomas
Malthus, 1798
 Economist
 Observed
________________________
 Population size _________such
as the Food Supply
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The Struggle for Existence
 Malthus’
Influence:
– ______________________________
______________________________
 Each
Species Struggles For:
– Food
– Living Space
– Mates
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Population Growth


Malthus Reasoned That
If The Human
Population Continued To
Grow Unchecked,
Sooner or Later There
Would Be Insufficient
Living Space & Food For
Everyone
Death Rate Will
Increase To Balance
Population size & Food
Supply
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Population Growth


Darwin Realized
Malthus’s Principles
Were Visible In
Nature
Plants & Animals
__________________
__________________
__________________
– Most Die
– If They Didn’t – Earth
Would Be Overrun
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Darwin’s Theory of
Evolution
Organisms Change Over Time
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Common Descent with
Modification

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Darwin proposed
that organisms
descended from
______________
Idea that
organisms
________,
diverging from a
common form
Caused
___________ copyright cmassengale
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Natural Selection

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
________for evolution
During the struggle for
resources,
___________
Idea that at least
some of the
differences between
individuals, which
impact their survival
and fertility, are
___________
.
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