class3-chapt 26 lecture-ortega-spring2016-origin of life-no-clickers.ppt

8/19/2019 Class3-chapt 26 lecture-ORTEGA-Spring2016-ORIGIN OF LIFE-no-clickers.ppt

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The Origin and Diversity of Life

Chapter 26


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Deep Time1) Geologic time is divided into four eons

– Hadean from Hades ! "ell)# $%&'' (* – $%''' (*

– Archean from Arkhē = Origin% ancient)# $%''' (* – 2%&'' (*

– Proterozoic from Proteros ! +arlier , Zoōs = Life)# 2%&'' (* – 6''

(*

– Phanerozoic -haneros ! .isi/le% evident , Zoōs = Life)# 6'' (* –

-resent

2) The +arth formed as a hot mass of molten roc0 a/out

4,500 (*) – *s it cooled% chemicallyrich oceans ere formed from ater

condensation

3) Life originated appro4imately 3,500 (* in the *rchean

2

(* ! (illion years ago


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3

Periods E o n s

E r a s

C e n o z o i c

M e s o z o i c

P h a n e r o z o i c

P a l e o z

o i c

P r o t

e r o z o i c

L a t e

M i d d l e

E a r l y

L a t e

M i d d l e

E a r l y A

r c h e a n

H

a d e a n

Quaternary

Tertiary

Cretaceous

Jurassic

Triassic

Permian

Caroni!erous

"e#onian

$ilurian

%rdo#ician

Camrian

Present

50 M'A

(00 M'A

(50 M'A

)00 M'A

)50 M'A

300 M'A

350 M'A

400 M'A

450 M'A

500 M'A

(000 M'A

(500 M'A

)000 M'A

)500 M'A

3000 M'A

3500 M'A

4000 M'A

4500 M'A

A**earance o! humans

+irst *rimate

ird radiation

Mammal radiation

Pollinatin- insects

"i#ersi!ication o! !lo.erin- *lants

+irst !lo.erin-*lants, irds,

marsu*ial

mammals

+irst dinosaurs

+irst -ymnos*erms

+irst re*tiles

+irst am*hiians

ony !ish, tetra*ods, seed *lants,

and insects a**ear

Early #ascular *lants di#ersi!y

/n#erterates dominate

+irst land *lantsCamrian e*losion1 increase in di#ersityA**earance o! animals and *lants

+irst multicellular or-anisms

%ldest de!inite !ossils o!

eu2aryotes

A**earance o! oy-en in atmos*hereCyanoacteria

%ldest !ossils o! *ro2aryotesMoltenhot sur!ace o! Earth ecomes some.hat cooler

%ldest roc2s

+ormation o! Earth

0

30


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5 Continents moved over geological time

– +arths crust formed rigid sla/s of roc0 called plates

5 7nder continents and oceans5 Three main su*ercontinents formed#

– 8odinia all continents – /eteen 191 /illion and

:&' million years ago) – -angea all continents – 3''%'''%''' years ago)

– Gondana all current ;outhern "emisphere

continents)#

5 +4isted /efore -angea – &''%'''%''' years ago

5


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&

Periods E o n s

E r a s

C e n o z o i c

M e s o z o i c

P h a n e r o z o i c

P a l e o z

o i c

P r o t e r o z o i c

L a t e

M i d d l e

E a r l y

L a t e

M i d d l e

E a r l y

A r c h e a n

H a d e a n

Quaternary

Tertiary

Cretaceous

Jurassic

Triassic

Permian

Caroni!erous

"e#onian

$ilurian

%rdo#ician

Camrian

Present

50 M'A

(00 M'A

(50 M'A

)00 M'A

)50 M'A

300 M'A

350 M'A

400 M'A

450 M'A

500 M'A

(000 M'A

(500 M'A

)000 M'A

)500 M'A

3000 M'A

3500 M'A

4000 M'A

4500 M'A

A**earance o! humans

+irst *rimate

ird radiation

Mammal radiation

Pollinatin- insects

"i#ersi!ication o! !lo.erin- *lants

+irst !lo.erin- *lants, irds,

marsu*ial mammals

+irst dinosaurs

+irst -ymnos*erms

+irst re*tiles

+irst am*hiians

ony !ish, tetra*ods, seed *lants,

and insects a**ear

Early #ascular *lants di#ersi!y

/n#erterates dominate

+irst land *lants

Camrian e*losion1 increase in di#ersity

A**earance o! animals and *lants

+irst multicellular or-anisms

%ldest de!inite !ossils o! eu2aryotes

A**earance o! oy-en in atmos*here

Cyanoacteria

%ldest !ossils o! *ro2aryotes

Moltenhot sur!ace o! Earth ecomes some.hat cooler

%ldest roc2s

+ormation o! Earth

orth and $outh

America 6oined

y land rid-e78*li!t o! the

$ierra e#ada7

9orld.ide -laciation7

:ond.ana e-insto rea2 a*art1

interior less arid7

Pan-ea intact7/nterior o! Pan-eaarid7 Climate

#ery .arm7

$u*ercontinent o!

Laurentia to the

north and:ond.ana to the

south7 Climate mild7

$u*ercontinent o! :ond.ana !orms7%ceans co#er much o! orth America7

Climate not .ell 2no.n7

Most o! Earth is co#ered

in ocean and ice7

0

:ond.ana:ond.ana

Pan-eaPan-eaPan-ea

LaurentiaLaurentia

;odinia;odinia

0

0

0

0

30

0

30

$outh Pole$outh Pole<






:ond.ana:ond.ana

:ond.ana:ond.ana

:ond.ana


=rom this point onard

geological evidenceimproves to understand

the dynamics of plate

tectonics


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Conditions on +arly +arth5 ;eems li0ely that +arths first organisms 39> – 29&


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Organic molecules may have

originated on early +arth5 8educing atmosphere

– 8ich in#

5 Car/on dio4ide CO2)

5 ?itrogen gas ?2)5 @ater vapor "2O)

5 "ydrogen gas "2)

5 Other sulfur% nitrogen% and car/on compounds – Lac0 of

5 O4ygen gas O2)

:


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5 An 1B&3% (iller and 7rey did an e4perimentthat reproduced early atmosphere

– *ssem/led reducin- atmos*here rich

in hydro-en ith no o4ygen gas –8educing atmosphere placed over liuid

ater

–Temperature /elo /ut near 1''C –;imulate lightning ith spar0s

>

Miller and 8rey e*eriment


9/31B

(any of the o/tained molecules

are 0ey molecules of life


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5 =ound ithin a ee0 that methane gas C"$)

converted into other simple car/on

compounds – Compounds com/ined to form simple

molecules and then more comple4

molecules

5 Later e4periments produced more than 3'

car/on compounds including amino acids

– *denine also produced purine that is part

of the D?* molecule)

1'


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The =irst Cells5 (icrofossils are fossiliEed forms of

microscopic life

– Oldest are 39& /illion years old

5 Tiny structures 1 2 Fm in diameter)

5 ;pectroscopic analyses shos that they

contain comple4 car/on molecules

5 ;eem to resem/le presentday pro0aryotes

– 392 /illion year old microfossils from mats

of shallo marine environment

5 3'' Fm in diameter

5 ;urrounding /y car/onaceous all

structures

11

(00 =m


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5 Living things are selective in the car/onisotopes used

– Living things preferentially incorporate

C12 sta/le isotope car/on) – C12 of organisms is higher than in the

atmosphere

– Asotopic analysis of C12 in fossilssuggests that car/on fi4ation as active

as much as 39>


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+arths Changing ;ystem

5 Climate temperature and ater availa/ility)

and atmos*here com*osition among

many factors that affect species survival

5 Dramatic shifts in all these factors led to

mass etinctions influencing the course ofevolution

– +arth has /een cooling since its formation

– +4treme drops in temperature resulted in

glacial ice covering +arth pole to pole) at

least four times since the *rchaean 13


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1$

Three glo/al glaciation events occurred during the -roteroEoic

Copyright The (cGra"ill Companies% Anc9 -ermission reuired for reproduction or display9

Phanerozoic

$olar $ystem %ri-in

;e-ional

-laciation$no.all

Earth

0

500

(000

(500

)000

)500

3000

3500

4000

4500

Proterozoic

T i m e

> M ' A ?

Archaean

Hadean

Origin of

Cyano/acteria

=irst

pro0aryotes


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5 O4ygenic photosynthesis produced atmospheric O2

5 O2 is an atmospheric gas of organic origin 21H)9

;econd most important gas

5 O2 as not present in early atmosphere

5 One /ig mystery is the 2''millionyear lag /eteenthe origins of photosynthesis and su/stantial levels of

O29 +4planation#

– O2 reacted ith iron to form iron o4ide in the oceans

5 O2 in the atmosphere interacted ith ultraviolet 7.)

radiation from the ;un and formed O3 oEone)

– Critical to have life in the planet as it reduces the mutation

rate caused 7. light1&


16/31

16

*tmospheric O2 levels over time


0(70

Time >'A?

)70370

40

30

)0

(0

A t m o

s * h e r i c o 0 y -

e n

l e # e l > @ ?

%ri-in o!

Cyanoacteria

1:


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1:


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5 Did plants contri/ute to glaciationsI

5 Groing evidence that plants contri/uted to to glaciations9To e4planation cases#

1) ColoniEation of land /y plants J$B' (*% no #ascular*lants) folloed /y gradual cooling and a/rupt glaciation$>> to $$$ (*

5 They released organic acids

5 Organic acids increased roc0 eathering and released

-hosphorous

5 -hosphorous reached the oceans and increased algalphotosynthesis

5 Greenhouse gas CO2 as removed from the atmosphere

to form algal tissue5 8educed levels of atmospheric greenhouse gas CO2

alga , terrestrial plants) resulted in a glo/al temperaturedecrease and it triggered glaciation

1>


19/31

5 Did plants contri/ute to glaciationsI

5 Groing evidence that plants contri/uted toto glaciations9 To e4planation cases#

)? ascular *lants diversificationconcurrent ith another maKor

glaciation $'' to 36' (*)5 +4tensive root systems increased

eathering of roc0s and released

essential nutrients that furthertriggered algal gro in the oceans

5 Decrease of greenhouse gas CO2

1B


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+verChanging Life on +arth

5 Life evolved into three monophyleticdomains or clades

(? Euacteria

)? Archaea

3? Eu2aryotes

5 ;i4 supergroups identified ithin the

eu0aryotes

2'


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21

;i4 supergroups have /een identified ithin the

+u0aryote domain% one of three domains of life on +arth

A r c h a e a

C h r o m a l # e o l a t e s

; h i z a r i a

A r c h a e * l a s t i d a

E 0 c a # a t a

A m o e o z o a

% * i s t h o 2 o n

t a

E u a c t e r i a

Eu2aryotes


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5 +ndosym/iosis and the origin of eu0aryotes

– (itochondria and chloroplasts entered early

eu0aryotic cells /y endosym/iosis

5 * type of sym/iosis in hich one organism lives inside

the other% the to typically /ehaving as a single organism

5 (itochondria are the descendants of relatives of a

hy/ridM microrganism#

– Pur*le sul!ur acteria do not use ater /ut "ydrogen

sulfide as electron donor in photosynthesis% they release

sulfur instead of CO2)

– *nd the *arasite acteria Rickettsia origin of mitochondria

as a cell compartment)5 Chloroplasts are derived from cyano/acteria

22


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+ndosym/iosis#

*lgae acuired chloroplasts tice#

1)8ed algae and Green algae common ancestor# an+u0aryotic cell that engulfed a cyano/acteria

2)


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(ulticellularity leads to cell

specialiEation

5 7nicellular /ody plan still tremendouslysuccessfulNNNNN

– 7nicellular pro0aryotes and eu0aryotes

constituting a/out half of the /iomass on +arth

– ;ingle cell has limits ith cell specialiEation

specialiEed tas0s)

5 (ulticellularity alloed organisms to deal ith

environment in novel ays through differentiation9Truly multicellularity only in eu0aryots

2$

8 id di ifi ti d2&


25/31

8apid diversification occurred

during the Cam/rian5 +volutionary innovations occurred hile life as

primarily auatic

– -eriod of e4tremely rapid e4pansion of life

–+sta/lished the foundations for tremendous diversity

– Cam/rian radiation &$' (*) as confined to

ocean

– *ncestors of almost every group of animals evolved

– The Cam/rian radiation too0 place after the first trulymulticellular animals appeared J>'' (*)

2&

( K i ti ll d


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(aKor innovations alloed

for the move onto land

5 -lants and then animals coloniEed terrestrialenvironments after Cam/rian radiation

– +volution of photosynthesis protected

organisms on land#5 O2 rich atmosphere

5 OEone layer protected from 7. light

–At reuired innovations to preventdesiccation to effective gas e4changes

26

2:


27/31

Classi!ication o! %r-anisms

5 (ore than 2''' years ago% *ristotle divided livingthings into animals and plants

5 Later% Gree0s and 8omans descri/ed /asic units

ere called genera singular genus)

– Felis cats) and Equus horses)

5 An the 1:&'s% Carolus Linnaeus instituted the use of

topart names% or /inomials

– Apis mellifera the +uropean honey/ee

– Genus and species names capitaliEed% all in italics

2:

The -enus Felis


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2>

The -enus Felis

Felis chaus9 =rom southern China

in the east through ;outheast and

Central *sia to the ?ile .alley

Felis margarita9 Deserts of

northern *frica and

southest and central *sia

Felis nigripes9 ;outh

*frica% ?ami/ia% and


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5 Ta4onomy is the science of classifying living things

– * classification level is called a ta4on plural ta4a)

– There is a category hierarchy ith several levels9 +ach level

has uniue traits synapomorphiesNNN An red /elo) todifferentiate them

5 Class9 (ammalia At has 26 orders)9 (ammary glands and

hairs

5 Order9 Carnivora At has > families)9 -resence of ascarnassial teeth

5 =amily9 =elidae At has 13 genera)9 ;0ull ith short rostrum

and facial area and short inflated /raincase

5 Genus9 Felis At has si4 species)9 ;mall felines% cannot roar

/ecause uniue structure of the throat

5 ;pecies9 margarita Large ear pinnae and reduced eight

and siEe

2B


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3'

"ierarchical system used in classifying the eastern gray suirrel

"omain

Eu2arya

Bin-dom

Animalia

Phylum

Chordata

$u*hylum

erterata



31/31

31

Class

Mammalia

%rder

;odentia

+amily

$ciuridae

:enus

Sciurus

$*ecies

Sciurus

carolinensis

Sciurus

carolinensis


class3-chapt 26 lecture-ortega-spring2016-origin of life-no-clickers.ppt

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