chapter 26: the tree of life an introduction to biological diversity

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

Chapter 26:The Tree of Life

An Introduction to Biological Diversity


Figure 26.1 An artist’s conception of Earth 3 billion years ago


Figure 26.2 Can organic molecules form in a reducing atmosphere?

RESULTS As material circulated through the apparatus, Miller and Urey periodically collected samples for analysis. They identified a variety of organic molecules, including amino acids such as alanine and glutamic acid that are common in the proteins of organisms. They also found many other amino acids and complex,oily hydrocarbons.

EXPERIMENT Miller and Urey set up a closed system in their laboratory to simulate conditions thought to have existed on early Earth. A warmed flask of water simulated the primeval sea. The strongly reducing “atmosphere” in the system consisted of H2, methane (CH4), ammonia (NH3), and water vapor. Sparks were discharged in the synthetic atmosphere to mimic lightning. A condenser cooled the atmosphere, raining water and any dissolved compounds into the miniature sea.

Electrode

Condenser

Cooled watercontainingorganic molecules

H2O

Sample forchemical analysis

Coldwater

Water vaporCH4

H2NH

3

CONCLUSION Organic molecules, a first step in the origin of life, can form in a strongly reducing atmosphere.


26.3 Hydro Thermal Vent


Figure 26.4 Laboratory versions of protobionts

20 m

(a) Simple reproduction. This lipo-some is “giving birth” to smallerliposomes (LM).

(b) Simple metabolism. If enzymes—in this case, phosphorylase and amylase—are included in the solution from which the droplets self-assemble, some liposomes can carry out simple metabolic reactions and export the products.

Glucose-phosphate

Glucose-phosphate

Phosphorylase

Starch

Amylase

Maltose

Maltose

Phosphate


Figure 26.7 Radiometric dating

1 2 3 4

Accumulating “daughter”

isotope

Rat

io o

f pa

rent

isot

ope

to d

augh

ter

isot

ope

Remaining “parent” isotope

1

1

11

Time (half-lives)

2

4

816


Figure 26.8 Diversity of life and periods of mass extinction

Ca

mb

rian

Pro

tero

zoic

eo

n

Ord

ovi

cia

n

Silu

rian

De

von

ian

Ca

rbo

nife

rou

s

Pe

rmia

n

Tria

ssic

Jura

ssic

Cre

tace

ou

s

Pa

leo

ge

ne

Neo

gene

Num

ber of fam

ilies ( )

Number oftaxonomic

familiesExtinction rate

Cretaceous mass extinction

Permian mass extinction

Millions of years agoE

xtin

ctio

n ra

te (

)

Paleozoic Mesozoic

0

20

60

40

80

100600 500 400 300 200 100 0

2,500

1,500

1,000

500

0

2,000

Ceno-zoic


Table 26.1 The Geologic Record


Figure 26.10 Clock analogy for some key events in Earth’s history

Land plants

Animals

Multicellulareukaryotes

Single-celledeukaryotes

Atmosphericoxygen

Prokaryotes

Origin of solarsystem andEarth

Humans

Ceno-zoicMeso-

zoic

Paleozoic

ArchaeanEon

Billions of years ago

ProterozoicEon

1

2 3

4


Figure 26.13 A model of the origin of eukaryotes through serial endosymbiosis

Cytoplasm DNAPlasmamembrane

Ancestralprokaryote

Infolding ofplasma membrane

Endoplasmicreticulum

Nuclear envelope

Nucleus

Engulfingof aerobic

heterotrophicprokaryote

Cell with nucleusand endomembranesystem

Mitochondrion

Ancestralheterotrophiceukaryote Plastid

Mitochondrion

Engulfing ofphotosyntheticprokaryote insome cells

Ancestral Photosyntheticeukaryote


Figure 26.18 Earth’s major crustal plates

NorthAmericanPlate

CaribbeanPlate

Juan de FucaPlate

Cocos Plate

PacificPlate

NazcaPlate

SouthAmericanPlate

AfricanPlate

Scotia Plate AntarcticPlate

ArabianPlate

Eurasian Plate

PhilippinePlate

IndianPlate

AustralianPlate


Figure 26.19 Events at plate boundaries

Volcanoes andvolcanic islands

TrenchOceanic ridge

Oceanic crust

Seafloor spreading

Subduction zone


26.19 Lava Flow


26.19 Volcanic Eruption


Figure 26.20 The history of continental drift during the Phanerozoic

India collided with Eurasia just 10 millionyears ago, forming theHimalayas, the tallestand youngest of Earth’smajor mountainranges. The continentscontinue to drift.

By the end of theMesozoic, Laurasiaand Gondwanaseparated into thepresent-day continents.

By the mid-Mesozoic,Pangaea split intonorthern (Laurasia)and southern(Gondwana)landmasses.

Cen

ozo

ic

North AmericaEurasia

AfricaSouth

AmericaIndia

Madagascar

Antarctica Australia

Laurasia

Mes

ozo

ic Gondwana

At the end of thePaleozoic, all ofEarth’s landmasseswere joined in thesupercontinentPangaea.

Pangaea

Pal

eozo

ic

251

135

65.5

0

Mill

ions

of y

ears

ago


Figure 26.22 One current view of biological diversity

Pro

teob

acte

ria

Chl

amyd

ias

Spi

roch

etes

Cya

noba

cter

ia

Gra

m-p

ositi

ve b

acte

ria

Kor

arch

aeot

es

Eur

yarc

haeo

tes,

cre

narc

haeo

tes,

nan

oarc

haeo

tes

Dip

lom

onad

s, p

arab

asal

ids

Eug

leno

zoan

s

Alv

eola

tes

(din

ofla

gella

tes,

api

com

plex

ans,

cili

ates

)

Str

amen

opile

s (w

ater

mol

ds,

diat

oms,

gol

den

alga

e, b

row

n al

gae)

Cer

cozo

ans,

rad

iola

rians

Red

alg

ae

Chl

orop

hyte

s

Cha

roph

ycea

ns

Domain Archaea Domain Eukarya

Universal ancestor

Domain Bacteria

Chapter 27 Chapter 28


Bry

ophy

tes

(mos

ses,

live

rwor

ts,

horn

wor

ts)

Plants

Fungi

Animals

See

dles

s va

scul

ar p

lant

s (f

erns

)

Gym

nosp

erm

s

Ang

iosp

erm

s

Am

oebo

zoan

s (a

moe

bas,

slim

e m

olds

)

Chy

trid

s

Zyg

ote

fung

i

Arb

uscu

lar

myc

orrh

izal

fun

gi

Sac

fun

gi

Clu

b fu

ngi

Cho

anof

lage

llate

s

Spo

nges

Cni

daria

ns (

jelli

es,

cora

l)

Bila

tera

lly s

ymm

etric

al a

nim

als

(ann

elis

, ar

thro

pods

, m

ollu

scs,

ech

inod

erm

s, v

erte

brat

e)

Chapter 29 Chapter 30 Chapter 28 Chapter 31 Chapter 32 Chapters 33, 34

chapter 26: the tree of life an introduction to biological diversity

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