Transcript PowerPoint - Scranton Prep Biology

CAMPBELL BIOLOGY IN FOCUS
Urry • Cain • Wasserman • Minorsky • Jackson • Reece
23
Broad Patterns
of Evolution
Lecture Presentations by
Kathleen Fitzpatrick and Nicole Tunbridge
© 2014 Pearson Education, Inc.
Overview: Lost Worlds
 Past organisms were very different from those now
alive
 The fossil record shows evidence of macroevolution,
broad changes above the species level; for example
 The emergence of terrestrial vertebrates
 The impact of mass extinctions
 The origin of flight in birds
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Figure 23.1
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Figure 23.UN01
Cryolophosaurus skull
© 2014 Pearson Education, Inc.
Concept 23.1: The fossil record documents life’s
history
 The fossil record reveals changes in the history of
life on Earth
Video: Grand Canyon
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Figure 23.2
1m
100
mya
0.5 m
Rhomaleosaurus
victor
175
200
Dimetrodon
270
300
Tiktaalik
4.5 cm
Coccosteus cuspidatus
375
400
1 cm
Hallucigenia
560
Stromatolites
2.5 cm
500
510
Dickinsonia
costata
600
1,500
3,500
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Tappania
Figure 23.2a
Stromatolite cross
section
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Figure 23.2b
Stromatolites
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Figure 23.2c
Tappania
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Figure 23.2d
2.5 cm
Dickinsonia costata
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Figure 23.2e
1 cm
Hallucigenia
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Figure 23.2f
4.5 cm
Coccosteus cuspidatus
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Figure 23.2g
Tiktaalik
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Figure 23.2h
0.5 m
Dimetrodon
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Figure 23.2i
1m
Rhomaleosaurus victor
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The Fossil Record
 Sedimentary rocks are deposited into layers called
strata and are the richest source of fossils
 The fossil record indicates that there have been
great changes in the kinds of organisms on Earth at
different points in time
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 Few individuals have fossilized, and even fewer
have been discovered
 The fossil record is biased in favor of species that
 Existed for a long time
 Were abundant and widespread
 Had hard parts
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How Rocks and Fossils Are Dated
 Sedimentary strata reveal the relative ages of fossils
 The absolute ages of fossils can be determined by
radiometric dating
 A “parent” isotope decays to a “daughter” isotope
at a constant rate
 Each isotope has a known half-life, the time
required for half the parent isotope to decay
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Fraction of parent
isotope remaining
Figure 23.3
½
Remaining
“parent”
isotope
1
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Accumulating
“daughter”
isotope
¼
⅛
2
3
Time (half-lives)
1
4
16
 Radiocarbon dating can be used to date fossils up
to 75,000 years old
 For older fossils, some isotopes can be used to date
volcanic rock layers above and below the fossil
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The Geologic Record
 The geologic record is a standard time scale
dividing Earth’s history into the Hadean, Archaean,
Proterozoic, and Phanerozoic eons
 The Phanerozoic encompasses most of the time
that animals have existed on Earth
 The Phanerozoic is divided into three eras: the
Paleozoic, Mesozoic, and Cenozoic
 Major boundaries between geological divisions
correspond to extinction events in the fossil record
Animation: The Geologic Record
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Table 23.1
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Table 23.1a
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Table 23.1b
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 The oldest known fossils are stromatolites, rocks
formed by the accumulation of sedimentary layers
on bacterial mats
 Stromatolites date back 3.5 billion years ago
 Prokaryotes were Earth’s sole inhabitants for more
than 1.5 billion years
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 Early prokaryotes released oxygen into the
atmosphere through the process of photosynthesis
 The increase in atmospheric oxygen that began 2.4
billion years ago led to the extinction of many
organisms
 The eukaryotes flourished in the oxygen-rich
atmosphere and gave rise to multicellular organisms
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The Origin of New Groups of Organisms
 Mammals belong to the group of animals called
tetrapods
 The evolution of unique mammalian features can be
traced through gradual changes over time
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Figure 23.4
†Dimetrodon
Key to skull bones
Articular
Dentary
Quadrate
Squamosal
Early cynodont (260 mya)
Cynodonts
Therapsids
Synapsids
OTHER
TETRAPODS
Reptiles
(including
dinosaurs and birds)
Synapsid (300 mya)
†Very late (non-
mammalian)
cynodonts
Mammals
Temporal
fenestra
(partial view)
Hinge
Later cynodont (220 mya)
Temporal
fenestra
Hinge
Original hinge
New hinge
Therapsid (280 mya)
Very late cynodont (195 mya)
Temporal
fenestra
Hinge
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Hinge
Figure 23.4a
Reptiles
(including
dinosaurs and birds)
†Dimetrodon
Cynodonts
Therapsids
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Synapsids
OTHER
TETRAPODS
†Very late (nonmammalian)
cynodonts
Mammals
 Synapsids (300 mya) had single-pointed teeth,
large temporal fenestra, and a jaw hinge between
the articular and quadrate bones
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 Therapsids (280 mya) had large dentary bones,
long faces, and specialized teeth, including large
canines
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Figure 23.4b
Synapsid (300 mya)
Key to skull bones
Temporal
fenestra
Articular
Quadrate
Dentary
Squamosal
Hinge
Therapsid (280 mya)
Temporal
fenestra
Hinge
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 Early cynodonts (260 mya) had large dentary
bones in the lower jaw, large temporal fenestra in
front of the jaw hinge, and teeth with several cusps
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 Later cynodonts (220 mya) had teeth with complex
cusp patterns and an additional jaw hinge between
the dentary and squamosal bones
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 Very late cynodonts (195 mya) lost the original
articular-quadrate jaw hinge
 The articular and quadrate bones formed inner ear
bones that functioned in transmitting sound
 In mammals, these bones became the hammer
(malleus) and anvil (incus) bones of the ear
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Figure 23.4c
Early cynodont (260 mya)
Temporal
fenestra
(partial view)
Hinge
Later cynodont (220 mya)
Original hinge
New hinge
Very late cynodont (195 mya)
Hinge
© 2014 Pearson Education, Inc.
Key to skull bones
Articular
Quadrate
Dentary
Squamosal
Concept 23.2: The rise and fall of groups of
organisms reflect differences in speciation and
extinction rates
 The history of life on Earth has seen the rise and fall
of many groups of organisms
 The rise and fall of groups depend on speciation
and extinction rates within the group
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Figure 23.5
†
Lineage A
†
†
†
†
Lineage B
Common
ancestor of
lineages A
and B
4
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†
3
2
1
Millions of years ago
0
Plate Tectonics
 At three points in time, the landmasses of Earth
have formed a supercontinent: 1.1 billion, 600
million, and 250 million years ago
 According to the theory of plate tectonics, Earth’s
crust is composed of plates floating on Earth’s
mantle
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Figure 23.6
Crust
Mantle
Outer
core
Inner
core
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 Tectonic plates move slowly through the process of
continental drift
 Oceanic and continental plates can separate, slide
past each other, or collide
 Interactions between plates cause the formation of
mountains and islands and earthquakes
Video: Lava Flow
Video: Volcanic Eruption
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Figure 23.7
Juan
de Fuca
Plate
North
American
Plate
Caribbean
Plate
Cocos Plate
Pacific
Plate
Nazca
Plate
South
American
Plate
Scotia
Plate
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Eurasian Plate
Philippine
Plate
Arabian
Plate
Indian
Plate
African
Plate
Antarctic
Plate
Australian
Plate
Consequences of Continental Drift
 Formation of the supercontinent Pangaea about
250 million years ago had many effects
 A deepening of ocean basins
 A reduction in shallow water habitat
 A colder and drier climate inland
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Figure 23.8
Present
Collision of
India with
Eurasia
Cenozoic
45 mya
Eurasia
Africa
65.5 mya
South
America
India
Present-day
continents
Madagascar
Antarctica
251 mya
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Paleozoic
135 mya
Mesozoic
Laurasia
Laurasia and
Gondwana
landmasses
The supercontinent
Pangaea
Figure 23.8a
251 mya
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Paleozoic
135 mya
Mesozoic
Laurasia
Laurasia and
Gondwana
landmasses
The supercontinent
Pangaea
Figure 23.8b
Present
Collision of
India with
Eurasia
Cenozoic
45 mya
65.5 mya
Eurasia
Africa
South
America
India
Madagascar
Antarctica
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Present-day
continents
 Continental drift can cause a continent’s climate to
change as it moves north or south
 Separation of landmasses can lead to allopatric
speciation
 For example, frog species in the subfamilies
Mantellinae and Rhacophorinae began to diverge
when Madagascar separated from India
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Figure 23.9
Mantellinae
(Madagascar only):
100 species
Rhacophorinae
(India/southeast
Asia): 310 species
80
1
60
20
40
0
2 Millions of years ago (mya)
2
1
India
Madagascar
88 mya
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56 mya
 The distribution of fossils and living groups reflects
the historic movement of continents
 For example, the similarity of fossils in parts of South
America and Africa is consistent with the idea that
these continents were formerly attached
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Mass Extinctions
 The fossil record shows that most species that have
ever lived are now extinct
 Extinction can be caused by changes to a species’
environment
 At times, the rate of extinction has increased
dramatically and caused a mass extinction
 Mass extinction is the result of disruptive global
environmental changes
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The “Big Five” Mass Extinction Events
 In each of the five mass extinction events, more
than 50% of Earth’s species became extinct
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Figure 23.10
1,100
1,000
900
800
20
700
600
15
500
400
10
300
200
5
100
0
Era
Period
Mesozoic
Paleozoic
E
542
O
S
488 444 416
D
C
359
P
299 251
Tr
J
200
Time (mya)
© 2014 Pearson Education, Inc.
C
145
0
N Q
0
Cenozoic
P
65.5
Number of families:
Total extinction rate
(families per million years):
25
 The Permian extinction defines the boundary
between the Paleozoic and Mesozoic eras 251
million years ago
 This mass extinction occurred in less than 500,000
years and caused the extinction of about 96% of
marine animal species
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 A number of factors might have contributed to these
extinctions
 Intense volcanism in what is now Siberia
 Global warming resulting from the emission of large
amounts of CO2 from the volcanoes
 Reduced temperature gradient from equator to poles
 Oceanic anoxia from reduced mixing of ocean waters
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 The Cretaceous mass extinction 65.5 million years
ago separates the Mesozoic from the Cenozoic
 Organisms that went extinct include about half of all
marine species and many terrestrial plants and
animals, including most dinosaurs
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 The presence of iridium in sedimentary rocks
suggests a meteorite impact about 65 million
years ago
 Dust clouds caused by the impact would have
blocked sunlight and disturbed global climate
 The Chicxulub crater off the coast of Mexico is
evidence of a meteorite collision that dates to the
same time
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Figure 23.11
NORTH
AMERICA
Yucatán
Peninsula
Chicxulub
crater
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Is a Sixth Mass Extinction Under Way?
 Scientists estimate that the current rate of extinction
is 100 to 1,000 times the typical background rate
 Extinction rates tend to increase when global
temperatures increase
 Data suggest that a sixth, human-caused mass
extinction is likely to occur unless dramatic action
is taken
© 2014 Pearson Education, Inc.
Figure 23.12
Mass extinctions
Relative extinction rate of
marine animal genera
3
2
1
0
−1
−2
−3
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−2
−1
0
1
Cooler
Warmer
Relative temperature
2
3
4
Consequences of Mass Extinctions
 Mass extinction can alter ecological communities and
the niches available to organisms
 It can take 5–100 million years for diversity to recover
following a mass extinction
 The type of organisms residing in a community can
change with mass extinction
 For example, the percentage of marine predators
increased after the Permian and Cretaceous mass
extinctions
 Mass extinction can pave the way for adaptive
radiations
© 2014 Pearson Education, Inc.
Figure 23.13
Cretaceous
mass extinction
Predator genera (%)
50
Permian mass
extinction
40
30
20
10
0
Era
Period
Paleozoic
E
542
O
S
488 444 416
D
Mesozoic
C
359
P
299
Tr
251
Time (mya)
© 2014 Pearson Education, Inc.
J
200
Cenozoic
C
145
P
65.5
N
Q 0
Adaptive Radiations
 Adaptive radiation is the evolution of many
diversely adapted species from a common ancestor
 Adaptive radiations may follow
 Mass extinctions
 The evolution of novel characteristics
 The colonization of new regions
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Worldwide Adaptive Radiations
 Mammals underwent an adaptive radiation after the
extinction of terrestrial dinosaurs
 The disappearance of dinosaurs (except birds)
allowed for the expansion of mammals in diversity
and size
 Other notable radiations include photosynthetic
prokaryotes, large predators in the Cambrian, land
plants, insects, and tetrapods
© 2014 Pearson Education, Inc.
Figure 23.14
Ancestral
mammal
Monotremes
(5 species)
Marsupials
(324
species)
ANCESTRAL
CYNODONT
Eutherians
(5,010
species)
250
200
150
100
50
Time (millions of years ago)
© 2014 Pearson Education, Inc.
0
Regional Adaptive Radiations
 Adaptive radiations can occur when organisms
colonize new environments with little competition
 The Hawaiian Islands are one of the world’s great
showcases of adaptive radiation
Animation: Allometric Growth
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Figure 23.15
Close North American
relative, the tarweed
Carlquistia muirii
Dubautia laxa
KAUAI
5.1
million
years
MOLOKAI 1.3
million
OAHU
years
3.7
MAUI
million LANAI
years
N
Argyroxiphium
sandwicense
HAWAII
0.4
million
years
Dubautia waialealae
Dubautia scabra
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Dubautia linearis
Figure 23.15a
KAUAI
5.1
million
years
N
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MOLOKAI
1.3 million
OAHU
years
3.7
MAUI
million LANAI
years
HAWAII
0.4
million
years
Figure 23.15b
Close North American
relative, the tarweed
Carlquistia muirii
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Figure 23.15c
Dubautia waialealae
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Figure 23.15d
Dubautia laxa
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Figure 23.15e
Dubautia scabra
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Figure 23.15f
Argyroxiphium
sandwicense
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Figure 23.15g
Dubautia linearis
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Concept 23.3: Major changes in body form can
result from changes in the sequences and
regulation of developmental genes
 Studying genetic mechanisms of change can
provide insight into large-scale evolutionary change
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Effects of Development Genes
 Genes that program development influence the
rate, timing, and spatial pattern of changes in an
organism’s form as it develops into an adult
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Changes in Rate and Timing
 Heterochrony is an evolutionary change in the rate
or timing of developmental events
 It can have a significant impact on body shape
 The contrasting shapes of human and chimpanzee
skulls are the result of small changes in relative
growth rates
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Figure 23.16
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Chimpanzee infant
Chimpanzee adult
Chimpanzee fetus
Chimpanzee adult
Human fetus
Human adult
Figure 23.16a
Chimpanzee infant
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Chimpanzee adult
 Another example of heterochrony can be seen in
the skeletal structure of bat wings, which resulted
from increased growth rates of the finger bones
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Figure 23.17
Hand and
finger bones
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 Heterochrony can alter the timing of reproductive
development relative to the development of
nonreproductive organs
 In paedomorphosis, the rate of reproductive
development accelerates compared with somatic
development
 The sexually mature species may retain body
features that were juvenile structures in an ancestral
species
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Figure 23.18
Gills
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Changes in Spatial Pattern
 Substantial evolutionary change can also result from
alterations in genes that control the placement and
organization of body parts
 Homeotic genes determine such basic features as
where wings and legs will develop on a bird or how a
flower’s parts are arranged
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 Hox genes are a class of homeotic genes that
provide positional information during animal
development
 If Hox genes are expressed in the wrong location,
body parts can be produced in the wrong location
 For example, in crustaceans, a swimming
appendage can be produced instead of a feeding
appendage
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The Evolution of Development
 Adaptive evolution of both new and existing genes
may have played a key role in shaping the diversity
of life
 Developmental genes may have been particularly
important in this process
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Changes in Gene Sequence
 New morphological forms likely come from gene
duplication events that produce new developmental
genes
 A possible mechanism for the evolution of six-legged
insects from a many-legged crustacean ancestor
has been demonstrated in lab experiments
 Specific changes in the Ubx gene have been
identified that can “turn off” leg development
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Figure 23.19
Hox gene 6
Hox gene 7
Hox gene 8
Ubx
About 400 mya
Drosophila
© 2014 Pearson Education, Inc.
Artemia
Changes in Gene Regulation
 Changes in morphology likely result from changes
in the regulation of developmental genes rather than
changes in the sequence of developmental genes
 For example, threespine sticklebacks in lakes have
fewer spines than their marine relatives
 The gene sequence remains the same, but the
regulation of gene expression is different in the two
groups of fish
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Figure 23.UN03
Ventral spines
Threespine stickleback
(Gasterosteus aculeatus)
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Figure 23.20
Results
Hypothesis A: Differences in
sequence
Hypothesis B: Differences in
expression
Marine stickleback embryo:
expression in ventral spine and
mouth regions
Result: No
The 283 amino acids of the Pitx1
protein are identical.
Result: Yes
Lake stickleback embryo:
expression only in mouth
regions
Red arrows indicate regions of Pitx1
expression.
© 2014 Pearson Education, Inc.
Figure 23.20a
Marine stickleback embryo:
expression in ventral spine and
mouth regions
Red arrows indicate regions of Pitx1
expression.
© 2014 Pearson Education, Inc.
Figure 23.20b
Lake stickleback embryo:
expression only in mouth
regions
Red arrows indicate regions of Pitx1
expression.
© 2014 Pearson Education, Inc.
Concept 23.4: Evolution is not goal oriented
 Evolution is like tinkering—it is a process in which
new forms arise by the slight modification of
existing forms
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Evolutionary Novelties
 Most novel biological structures evolve in many
stages from previously existing structures
 Complex eyes have evolved from simple
photosensitive cells independently many times
 Exaptations are structures that evolve in one context
but become co-opted for a different function
 Natural selection can only improve a structure in the
context of its current utility
© 2014 Pearson Education, Inc.
Figure 23.21
(a) Patch of pigmented cells
Pigmented cells
(photoreceptors)
Epithelium
Nerve
fibers
(b) Eyecup
Pigmented
cells
Nerve fibers
Example: Patella, a limpet
Example: Pleurotomaria, a
slit shell mollusc
(c) Pinhole camera-type eye
(d) Eye with primitive lens
Epithelium
Fluid-filled
cavity
Cellular
mass
(lens)
Cornea
(e) Complex camera lenstype eye
Cornea
Lens
Optic
nerve
Pigmented
layer (retina)
Example: Nautilus
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Retina
Optic nerve
Example: Murex, a marine
snail
Optic
nerve
Example: Loligo, a squid
Figure 23.21a
(a) Patch of pigmented cells
Pigmented cells
(photoreceptors)
Epithelium
Nerve
fibers
Example: Patella, a limpet
© 2014 Pearson Education, Inc.
Figure 23.21b
(b) Eyecup
Pigmented
cells
Nerve fibers
Example: Pleurotomaria, a
slit shell mollusc
© 2014 Pearson Education, Inc.
Figure 23.21c
(c) Pinhole camera-type eye
Epithelium
Fluid-filled
cavity
Optic
nerve
Pigmented
layer (retina)
Example: Nautilus
© 2014 Pearson Education, Inc.
Figure 23.21d
(d) Eye with primitive lens
Cellular
mass
(lens)
Cornea
Optic nerve
Example: Murex, a marine
snail
© 2014 Pearson Education, Inc.
Figure 23.21e
(e) Complex camera lenstype eye
Cornea
Lens
Retina
Optic
nerve
Example: Loligo, a squid
© 2014 Pearson Education, Inc.
Evolutionary Trends
 Extracting a single evolutionary progression from
the fossil record can be misleading
 Apparent trends should be examined in a broader
context
 The species selection model suggests that
differential speciation success may determine
evolutionary trends
 Evolutionary trends do not imply an intrinsic drive
toward a particular phenotype
© 2014 Pearson Education, Inc.
35
40
45
55
© 2014 Pearson Education, Inc.
50
Hyracotherium
relatives
Archaeohippus
Hypohippus
Pliohippus
Mesohippus
Hyracotherium
Pliocene
5
Equus
Hippidion and
close relatives
Callippus
Nannippus
Neohipparion
Hipparion
Holocene
0
Pleistocene
Parahippus
20
Epihippus
Miohippus
Sinohippus
Megahippus
Anchitherium
Orohippus
Haplohippus
Palaeotherium
Pachynolophus
30
Propalaeotherium
25
Miocene
15
Oligocene
10
Eocene
Millions of years ago
Figure 23.22
Merychippus
Key
Grazers
Browsers
Figure 23.22a
55
© 2014 Pearson Education, Inc.
Miohippus
Haplohippus
Hyracotherium
relatives
Epihippus
Palaeotherium
50
Grazers
Browsers
Mesohippus
Orohippus
45
Pachynolophus
40
Propalaeotherium
35
Eocene
Millions of years ago
30
Oligocene
25
Hyracotherium
Figure 23.22b
Grazers
Browsers
Holocene
0
Pleistocene
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Merychippus
Hipparion
Pliohippus
Parahippus
Archaeohippus
Mio- Hypohippus
hippus
20
Anchitherium
Megahippus
15
Sinohippus
10
Miocene
Millions of years ago
Pliocene
5
Neohipparion
Equus
Figure 23.UN02
Species with
planktonic larvae
Species with
nonplanktonic
larvae
Paleocene
65
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60
Eocene
55
50
45
Millions of years ago (mya)
40
35
Figure 23.UN04
Flies and
fleas
Caddisflies
Herbivory
© 2014 Pearson Education, Inc.
Moths and
butterflies