Transcript 51b019bbe4b05b167ed2afcd-nincompoop

LECTURE PRESENTATIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 22
Descent with Modification:
A Darwinian View of Life
Lectures by
Erin Barley
Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Assignments:
- Study Chapter 22
- Do the MasteringBiology exercises for Chapt
22
http://www.wellcometreeoflife.org/video/
Overview: Endless Forms Most Beautiful
• A new era of biology began in 1859 when
Charles Darwin published The Origin of
Species
• Darwin noted that current species are
descendants of ancestral species
• Evolution can be defined by Darwin’s
phrase descent with modification
• Evolution can be viewed as both a pattern
and a process
© 2011 Pearson Education, Inc.
1809
Lamarck publishes his
hypothesis of evolution.
1798
Malthus publishes
“Essay on the Principle
of Population.”
1812
Cuvier publishes his extensive
studies of vertebrate fossils and
Proposed catastrophism.
1795
Hutton proposes
his principle of
gradualism.
1830
Lyell publishes
Principles of Geology.
1858
While studying species in
the Malay Archipelago,
Wallace (shown in 1848)
sends Darwin his hypothesis
of natural selection.
1790
1870
1809
183136
Charles Darwin
is born.
Darwin travels around
the world on HMS
Beagle.
1859
On the Origin of
Species is published.
1844
Darwin writes his
essay on descent
with modification.
1707 - 1778
Linnaeus developed
binomial naming for
species
.
The Galápagos Islands
Paleontology
Sedimentary rock
layers (strata)
Younger stratum
with more recent
fossils
Older stratum
with older fossils
1809
Lamarck publishes his
hypothesis of evolution.
1798
Malthus publishes
“Essay on the Principle
of Population.”
1812
Cuvier publishes his extensive
studies of vertebrate fossils and
Proposed catastrophism.
1795
Hutton proposes
his principle of
gradualism.
1830
Lyell publishes
Principles of Geology.
1858
While studying species in
the Malay Archipelago,
Wallace (shown in 1848)
sends Darwin his hypothesis
of natural selection.
1790
1870
1809
183136
Charles Darwin
is born.
Darwin travels around
the world on HMS
Beagle.
1859
On the Origin of
Species is published.
1844
Darwin writes his
essay on descent
with modification.
1707 - 1778
Linnaeus developed
binomial naming for
species
.
The Galápagos Islands
© 2011 Pearson Education, Inc.
1809
Lamarck publishes his
hypothesis of evolution.
1798
Malthus publishes
“Essay on the Principle
of Population.”
1812
Cuvier publishes his extensive
studies of vertebrate fossils and
Proposed catastrophism.
1795
Hutton proposes
his principle of
gradualism.
1830
Lyell publishes
Principles of Geology.
1858
While studying species in
the Malay Archipelago,
Wallace (shown in 1848)
sends Darwin his hypothesis
of natural selection.
1790
1870
1809
183136
Charles Darwin
is born.
Darwin travels around
the world on HMS
Beagle.
1859
On the Origin of
Species is published.
1844
Darwin writes his
essay on descent
with modification.
1707 - 1778
Linnaeus developed
binomial naming for
species
.
The Galápagos Islands
Figure 22.5
Darwin in 1840,
after his return
from the
voyage
HMS Beagle in port
Great
Britain
EUROPE
NORTH
AMERICA
ATLANTIC
OCEAN
The
Galápagos
Islands
AFRICA
PACIFIC
OCEAN
Pinta
Genovesa
Santiago
Fernandina
Isabela
0
20
40
Kilometers
Daphne
Islands
Pinzón
Santa Santa
Cruz
Fe
Florenza
Equator
SOUTH
AMERICA
Equator
Chile
PACIFIC
OCEAN
San
Cristobal
Española
Andes Mtns.
Marchena
Brazil
Malay Archipelago
PACIFIC
OCEAN
AUSTRALIA
Cape of
Argentina Good Hope
Cape Horn
Tasmania
New
Zealand
Figure 22.6
(b) Insect-eater
(a) Cactus-eater
(c) Seed-eater
The Origin of Species
• Darwin explained three broad observations:
– The unity of life
– The diversity of life
– The match between organisms and their
environment
© 2011 Pearson Education, Inc.
Figure 22.8
Hyracoidea
(Hyraxes)
Sirenia
(Manatees
and relatives)
†Moeritherium
†Barytherium
†Deinotherium
†Mammut
†Platybelodon
†Stegodon
†Mammuthus
Elephas maximus
(Asia)
Loxodonta africana
(Africa)
Loxodonta cyclotis
(Africa)
60
34
24
Millions of years ago
5.5 2 104 0
Years ago
Artificial Selection
Cabbage
Selection for
apical (tip) bud
Brussels
sprouts Selection for
axillary (side)
buds
Broccoli
Selection
for flowers
and stems
Selection
for stems
Selection
for leaves
Kale
Wild mustard
Kohlrabi
• Observation #1: Members of a population often
vary in their inherited traits
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• Observation #2: All species can produce more
offspring than the environment can support, and
many of these offspring fail to survive and
reproduce
© 2011 Pearson Education, Inc.
Figure 22.UN02
Observations
Individuals in a population
vary in their heritable
characteristics.
Organisms produce more
offspring than the
environment can support.
Inferences
Individuals that are well suited
to their environment tend to leave
more offspring than other individuals.
and
Over time, favorable traits
accumulate in the population.
Natural Selection: A Summary
• Individuals with certain heritable characteristics survive and
reproduce at a higher rate than other individuals
• Natural selection increases the adaptation of organisms to their
environment over time
• If an environment changes over time, natural selection may result in
adaptation to these new conditions and may give rise to new
species
Evolution is supported by an overwhelming
amount of scientific evidence
-Direct Observations of Evolutionary Change
-Homology
-Fossil records
-biogeography
© 2011 Pearson Education, Inc.
Direct Observations of Evolutionary Change
FIELD STUDY
Soapberry bug with beak
inserted in balloon vine fruit
Figure 22.13b
RESULTS
Beak
10
On native species,
southern Florida
8
Number of individuals
6
4
2
0
Ballon vine fruit
Museum-specimen average
10
On introduced species,
central Florida
8
6
4
2
0
6
7
8
9
Beak length (mm)
10
11
Goldenrain tree fruit
Figure 22.14
2,750,000
1
250,000 base pairs
2,500,000
Chromosome map
of S. aureus clone USA300
500,000
Key to adaptations
2,250,000
Methicillin resistance
Ability to colonize hosts
750,000
Increased disease severity
2,000,000
Increased gene exchange
(within species) and
toxin production
1,750,000
1,500,000
1,250,000
1,000,000
• CONCLUSION:
• Natural selection does not create new traits, but
edits or selects for traits already present in the
population
• The local environment determines which traits will
be selected for or selected against in any specific
population
© 2011 Pearson Education, Inc.
Homology
• Homology is similarity resulting from common
ancestry
• Homologous structures are anatomical
resemblances that represent variations on a
structural theme present in a common ancestor
• Examples of homologies at the molecular level are
genes shared among organisms inherited from a
common ancestor
© 2011 Pearson Education, Inc.
Mammalian forelimbs: homologous structures
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanges
Human
Cat
Whale
Bat
• Comparative embryology reveals anatomical
homologies not visible in adult organisms
Pharyngeal
pouches
Post-anal
tail
Chick embryo (LM)
Human embryo
• Vestigial structures are remnants of features
that served important functions in the
organism’s ancestors
Homologies and “Tree Thinking”
• Evolutionary trees are hypotheses about the
relationships among different groups
• Homologies form nested patterns in
evolutionary trees
• Evolutionary trees can be made using different
types of data, for example, anatomical and
DNA sequence data
© 2011 Pearson Education, Inc.
Figure 22.17
Branch point
Lungfishes
Amniotes
2
Digitbearing
limbs
Amnion
Mammals
Lizards
and snakes
3
4
Homologous
characteristic
Crocodiles
Ostriches
6
Feathers
Hawks and
other birds
Birds
5
Tetrapods
Amphibians
1
A Different Cause of Resemblance:
Convergent Evolution
• Convergent evolution is the evolution of similar, or analogous,
features in distantly related groups
• Analogous traits arise when groups independently adapt to
similar environments in similar ways
• Convergent evolution does not provide information about
ancestry
The Fossil Record
• The fossil record provides evidence of the
extinction of species, the origin of new groups,
and changes within groups over time
• Fossils can document important transitions
© 2011 Pearson Education, Inc.
Transition from land to sea in the ancestors of cetaceans
Other
even-toed
ungulates
Hippopotamuses
†Pakicetus
†Rodhocetus
Common
ancestor
of cetaceans
†Dorudon
Living
cetaceans
70
60
50
40
30
20
Millions of years ago
10
0
Key
Pelvis
Femur
Tibia
Foot
Eurasia
Africa
65.5
South
America
India
Madagascar
Antarctica
135
Mesozoic
Laurasia
251
Paleozoic
Millions of years ago
• Biogeography, the geographic distribution of
species, provides evidence of evolution
• Earth’s continents were formerly united in a
single large continent called Pangaea, but
have since separated by continental drift
Cenozoic
Present
Biogeography
What Is Theoretical About Darwin’s View
of Life?
• In science, a theory accounts for many
observations and data and attempts to explain and
integrate a great variety of phenomena
• Darwin’s theory of evolution by natural selection
integrates diverse areas of biological study and
stimulates many new research questions
• Ongoing research adds to our understanding of
evolution
© 2011 Pearson Education, Inc.