Change Over Time -Lesson 1

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

Change Over Time -Lesson 1

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