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8/9/2019 Change Over Time -Lesson 1
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Chapter 11
Lesson 1 – Evidence of Evolution
• What is evolution?
•
Evolution is change over time. – The scientic theory of evolution
explains ho living things descend fromearlier organisms.
– !t helps us understand the history of lifeon Earth.
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• What evidence supports evolution?
–"ossils
–#imilarities on $%& and proteinstructure
–#imilarities of 'ody structure
–#imilarities in Early $evelopment
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"ossils
– "ossils helped scientist inferred a'outthe shape and function of ancientorganisms( 'ody structures.
– They support the theory that livingorganisms evolved from earlier simplerorganisms.
– The "ossil )ecord*the millions of fossils
collected 'y scientists and organi+ed 'ydate, gives clues of ho and hen ane species evolved and ho organismsmay 'e related
#pecies – a group of similar organismsthat can mate ith each other andreproduce fertile o-spring.
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#imilarities in $%& and
protein #tructure
• #cientists infer that species inherited
many of the same genes from acommon ancestor.
• The more similar the $%& seuence
the more closely related the speciesare.
• The order of amino acids in proteins
can also sho ho closely relatedto species may 'e.
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#imilarities in /ody
#tructures• 0rganisms that share the same
'asic 'ody plan are assumed to have
come from a common ancestor. – erte'rates have a 'ac2'one.
– !nverte'rates do not have a 'ac2'one.
3omologous structures – structuresshared 'y species are attri'uted to acommon ancestor.
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#imilarities in early
$evelopment• #cientist also
infer evolutionaryrelationships 'ycomparing earlydevelopment of
organisms. – 0rganisms ith
common ancestry
loo2 similar duringthe early stages ofdevelopment.
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$arin %atural #election
• &n environmental change favors anexisting trait in an species givingthose mem'ers of the species anadvantage to survive and toreproduce4 passing on the favored
trait to their o-spring.
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Lesson 5 – $arin6s Theory
• http7889orida.p'slearningmedia.org8resource85:;a
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What is %atural #election?
• %atural selection is the )0CE## 'yhich individuals that have a variationthat matches the environment aremore li2ely to survive and reproducethan other mem'ers of the samespecies.
• ariations – di-erences 'eteenindividuals of the same species.
• &daptation – the variation that gives
organisms the advantage to surviveand reproduce.
• 0verproduction4 ariation4 Competition
and #election.
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• Environmental change4 Denes and%atural #election.
• The case of the oth during theindustrial revolution.
• The case of anti'iotic resistant'acteria and super 'ugs.
• White Li+ard
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Lesson : – /iodiversity and
Extinction• 3o do ne species form?& ne species can form hen a
group of individuals remain isolatedfrom the rest of its species longenough to evolved di-erent traits thatprevent reproduction.
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Why do species go extinct?
• Extinction – hen all mem'ers of aspecies disappear for Earth.
• rocess of extinction – Threaten species = in danger to 'ecome
endangered.
– Endangered species – in danger to'ecome extinct.
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Extinction and 3uman
&ctivities• Extinction is a natural process that
usually happens gradually.
• Extinction rates have increased do tohuman activities – ollution
– Contamination
– $estruction of ha'itats
– !nvasive species
– 3unting