Figure 24-9-Table 24-1

Figure 24-4a

Living species “succeed” fossil species

Fossil sloth from SouthAmerica

Present-day sloth fromSouth America

Figure 24-4b Transitional forms during the evolution of whales

Pakicetus, about 50 myo

Ambulocetus, about 49 myo

Rhodocetus, about 47 myo

Basilosaurus, about 38 myo

Figure 24-5a

The human tailbone is a vestigial trait.

Humancoccyx

Capuchinmonkey tail

(used for balance, locomotion)

Figure 24-6

Four mockingbird species on the Galápagos islands

Westernislands

Nesomimus parvulus

Darwin reasoned that they share a common ancestor.

Southernislands

Centralislands

Easternislands

Galápagosislands

Nesomimus melanotis

Nesomimus macdonaldiNesomimus trifasciatus

Mockingbirds from….

Southernislands

Easternislands

Westernislands

Centralislands

An ancestral populationcolonized the islands

Over time, thepopulationdiversified into several distinct species on different island groups

Figure 27-2 Homoplasy: Traits are similar but were not inherited from a common ancestor.

Homology: Similarities are inherited from a common ancestor.

Ichthyosaur

Synap

sids

Monotremes

Marsupial

sElep

hants

Primate

s

Rodents

Whales a

nd

dolphinsPter

osaurs

Dinosaurs

Birds

Ichthyo

saurs

Lizard

s

Common dolphin

Flatworm

s

The dolphin and ichthyosaurlineages are far apart on theevolutionary tree, suggestingthat they are not closelyrelated

The members of lineagesbetween the dolphins andichthyosaurs do not haveadaptations such as:– streamlined bodies– long jaws filled with teeth– fins and flippers

Fruit-fly Hox complex

Human Hox complex

The genes in the Hoxcomplexes of fruit fliesand humans have similarsequences and are in thesame order on theirchromosomes

Infer that commonancestor had 8Hox genes

Annelids, mollusks, andechinoderms also haveHox genes

(inse

cts, s

piders,

Arthro

podscru

stace

ans)

leech

es)

(earth

worms,

Annelids

squid)

(snail

s, cla

ms,

Mollusk

s

Echinoderm

s

(sea s

tars,

sand dolla

rs)

Chordate

s(ve

rtebrat

es)

Figure 24-7

Aniridia (Human)

eyeless (Fruit fly)

Only six of the 60 amino acids in these sequences are different. The two sequences are 90% identical.

Amino acid sequence (single-letter abbreviations):Gene:

Figure 24-8

Chick Human House cat

TailTailTail

Gill pouch Gill pouch Gill pouch

Figure 24-9

Turtle Human

Humerus

Radius and ulna

CarpalsMetacarpalsPhalanges

Horse Bird Bat Seal

Figure 24-13b-setup

Figure 24-13c-results

Figure 24-14

Overall body size has decreased

No net change in beak size over this interval

Beaks have become more pointed

Figure 27-8a

The Precambrian (Hadean, Archaean, and Proterozoic Eons) included the origin of life, photosynthesis, and the oxygenatmosphere.

Form

ation

of solar

syste

m

Moon f

orms

Earth fo

rmati

on co

mplete

Liquid w

ater o

n Earth

First

ocean

s; hea

vy bom

bardmen

t

fro

m spac

e ends

Origin of li

fe

First

eviden

ce of p

hotosy

nthetic

ce

lls

First

evide

nce of o

xygen

ic

ph

otosynthes

isFir

st ro

cks c

ontaining ox

ygen

(in

atmosp

here an

d ocean

)

First

euka

ryotic

foss

ils

First

photosy

nthetic e

ukaryo

tes

First

red al

gae; fi

rst ev

idence

of

sexu

al str

uctures

First

lichen

-like o

rgan

ism

First

spong

es; fi

rst bi

latera

lly

sy

mmetric

anim

als; o

cean

complet

ely oxy

genate

d

Proterozoic Eon

Multicellularorganisms beginto diversify slowly

Most of Earth is coveredin ocean and ice.

All life is unicellular

Position of the continents unknown

Archaean EonHadean Eon

Millions of years ago (mya)

Figure 27-8b

Phanerozoic Eon: The Paleozoic Era included the origin early diversification of animals, land plants, and fungi.

First

comb j

ellies

, arth

ropod

s,

ve

rtebrat

es, o

ther phyla

Cambrian

Algae abundant,marineinvertebratesdiversify

Arthro

pods dive

rsify;

fir

st ec

hinoderm

First

bryozo

ans (

newes

t

an

imal

phylum)

First

land pl

ants

First

mycorrh

izal fu

ngi (Glomale

s)

First

carti

laginous f

ish

First

bony fis

hFir

st inse

cts

First

fish w

ith ja

ws

First

ferns,

vasc

ular p

lants,

as

comyc

ete fu

ngi, lic

hens o

n land

First

tree-s

ized plan

ts

First

winged

inse

cts

First

tetrap

ods (a

mphibian

s)

First

seed

plants

First

plants

with le

aves

First

reptile

s

First

mammal-

like r

eptile

s

First

basidiomyc

ete fu

ngi

First

vess

els

in plan

ts

Ordovician Silurian Devonian Carboniferous PermianMississippian Pennsylvanian M

ass

extin

ctio

n

Mas

sex

tinct

ion

Mas

sex

tinct

ion

Echinoderms(sea stars, seaurchins) diversify

Coralreefsexpand

First upland plantcommunities(evergreen forests),diversification of fish,emergence ofamphibians

Insects diversify,coal-forming swampsabundant, sharksabundant, radiationof amphibians

Coal-forming swampsdiminish; parts ofAntarctica forested

Supercontinent Pangeaassembles. Building ofAppalachian Mountains ends.Climate warm; little variation.

Supercontinent of Laurentiato the north and Gondwanato the south. Climate mild.

Climate cold;extensive icein Gondwana.

Supercontinent of Gondwanaforms. Oceans cover much ofNorth America. Climate notwell known.

Laurentia

Gondwana

Pangea

GondwanaGondwana

Figure 27-8c

Phanerozoic Eon: The Mesozoic Era is sometimes called the Age of Reptiles.Fir

st nec

tar-drin

king in

sects

Triasssic

Gymnosperms become dominantland plants; extensive deserts

Mas

sex

tinct

ion

First

dinosaurs

First

mammals

First

tyran

nosau

rid dino

saur

First

angios

perm (fl

owering p

lant)

First

bird (A

rchae

opteryx

)Fir

st ce

ntric

diatom

s

First

water li

lies

First

magno

lia-fa

mily plan

ts

First

bee; fi

rst an

t

First

placen

tal m

ammals

Mas

sex

tinct

ion

Jurassic Mas

sex

tinct

ion

Cretaceous

Gymnosperms continueto dominate land

Dinosaurs diversify Flowering plants diversify

Pangea intact. Interiorof Pangea arid. Climatevery warm.

Pangea begins to break apart;interior of continent still arid.

Gondwana begins to breakapart; interior less arid.

India separated from Madagascar,moves north; Rocky Mountainsform. Climate mild, temperate.

Pangea

Pangea Gondwana

Figure 27-8d

Phanerozoic Eon: The Cenozoic Era is nicknamed the Age of Mammals.

First

horses

Paleogene

Continents continue to drift apart.Collision of India with Eurasia begins.Australia moves north from Antarctica.Palms in Greenland and Patagonia.

First

primate

s

First

fully aq

uatic w

hales

First

apes

Oldest p

ollen fr

om

da

isy-fa

mily pl

ants

Earlies

t hom

inins

Homo

sapien

s

Paleocene Eocene OligoceneNeogene

Miocene Pliocene Pleistocene

Diversification of grazing mammalsDiversification of angiospermsand pollinating insects

Diversification ofmammalian orders

Strong drying trend inAfrica and other continents;grasslands form. Alps andHimalayas begin to rise.

Continents close to presentposition. Beginning ofAntarctic ice cap. Openingof Red Sea.

North and South Americajoined by land bridge.Uplift of the Sierra Nevada.Worldwide glaciation.

http://vathena.arc.nasa.gov/curric/land/global/climchng.html

These two figures show former temperatures with major periods of glaciation labeled. The dashed lines are the present global average temperature of about 15° C (59° F). Thus the solid curves show small changes from this average; note that the temperature drops only about 5° C during a glaciation. This has occurred about every 100,000 years, with smaller wiggles in between. That is, there has been a 100,000 year glaciation cycle for the past million years or so, and there may be shorter cycles as well.

http://www.public.iastate.edu/~alloquep/eco/geoHist.html

http://www.public.iastate.edu/~alloquep/eco/geoHist.html