Download Unit 3 - History of Life on Earth

8/6/2013
Unit 3: Ideas of How Life Changes
Over Time
History of Life on Earth
Mrs. Petrov
Empedocles
• Lived from ________________
• Sicily (Greek governance)
• 4 elements of the universe
____________________
____________________
____________________
____________________
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Empedocles Theories
• The first creatures had been disembodied
____________________________.
• These organs finally joined into whole
organisms, through the force of “Love”.
Empedocles Theories
• Some of these organisms, being monstrous
and unfit for life, had died out.
• Chance, not the Gods, played the major role
of organism selection.
• Conceived of his "natural selection" as a past
event, not as an ongoing process.
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___________________________
• Lived from 384 - 322 BC
• Greece
Aristotle’s Theories
• _____________________all matter.
• Living things want to be _________________
(most “perfect”).
• As organisms form they die off if not in the
most perfect form.
• Many species present since there are so
many “_________________” to be human.
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Fall of the Empires
• Greek and Roman empires collapsed and
Christianity became dominant.
• All ideas of “evolution” were thought of as
sacrilegious.
• Other religions played a role during this
time…
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Islamic Views
• Al-Jahiz (776-878 AD) speculated on the
influence of the _______________________
on animals and considered the effects of the
environment on the likelihood of an animal to
survive.
Islamic Views
• Ibn Khaldun (1332-1406 AD)
• Muqaddimah (first published in
1377)
• Humans developed from "the
world of the
___________________"
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Taoism Views
• Chuang Tzu
• Denied that species are “fixed” and proposed
that species had developed different
characteristics in response to differing
_________________________
Evaluation
• For each scientist/philosopher…
– Describe some good AND bad points of their
ideas
• Evaluate the role of religion/”Gods” in 3 of
the above ideas. Was it a positive influence or
a negative influence, and why do you think
that?
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The Physical Aspect
• Immense evidence from the
________________ _______________ has
provided insight into how life changes.
• Catastrophism
vs.
Gradualism
_________________________________
• Georges _____________________– 1800’s
• Idea that sudden, recurring catastrophes are
responsible for many features present on
Earth.
–
–
–
–
Mountains
Water in certain places but not others
“Banding” in rock layers
Loss of plant/animal species
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________________________________
• ____________________________________
– The Earth has been subjected to slow, gradual
forces over it’s history.
– The land we see today was not the same land
one would see thousands of years ago.
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Does life do this too?
• Scientists proposed numerous theories to
explain how life itself changes.
• Many more un-published records of possible
mechanisms than those actually published…
Three Major Ideas
• Life is unchanging
• Life changes according to a ‘Plan’
• Life changes in response to environmental
changes
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Unchanging?
• Changes in ________lead to changes in
_______________________________… just
within days sometimes!
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Intelligent Design
• Some “agent” designed all life and has a plan
for them.
• Imperfect organisms aren’t imperfect, we just
can’t see the perfection.
Intelligent Design?
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Environmental Influence
• Organisms change in response to changing
environments
• This has been the major route for scientific
studies on how life changes over time.
The Darwinian revolution challenged
traditional views of a young Earth
inhabited by unchanging species
• Darwin’s ideas had deep historical roots
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1809
Lamarck publishes his
hypothesis of evolution.
1798
Malthus publishes
“Essay on the Principle
of Population.”
1812
1858
Cuvier publishes his extensive
studies of vertebrate fossils.
1795
Hutton proposes
his principle of
gradualism.
1830
Lyell publishes
Principles of Geology.
While studying species in
the Malay Archipelago,
Wallace (shown in 1848)
sends Darwin his hypothesis
of natural selection.
1790
1809
183136
Charles Darwin
is born.
Darwin travels around
the world on HMS
Beagle.
1870
1859
On the Origin of
Species is published.
1844
Darwin writes his
essay on descent
with modification.
The Galápagos Islands
Ideas About Change over Time
• The study of _________________ helped to
lay the groundwork for Darwin’s ideas
• Fossils are remains or traces of organisms
from the past, usually found in sedimentary
rock, which appears in layers or ___________
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Figure 22.3
Sedimentary rock
layers (strata)
Younger stratum
with more recent
fossils
Older stratum
with older fossils
• Paleontology, the study of fossils, was largely
developed by French scientist Georges Cuvier
• Cuvier advocated catastrophism, speculating
that each boundary between strata represents
a catastrophe
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• Geologists James Hutton and Charles Lyell
perceived that changes in Earth’s surface can
result from slow continuous actions still
operating today
• Lyell’s principle of
__________________________________
states that the mechanisms of change are
constant over time
• This view strongly influenced Darwin’s thinking
Lamarck’s Hypothesis of Evolution
• Lamarck hypothesized that species evolve
through ___________________________ of
body parts and the inheritance of
__________________________ characteristics
• The mechanisms he proposed are unsupported
by evidence
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• Carolus Linnaeus interpreted organismal
adaptations as evidence that the Creator had
designed each species for a specific purpose
• Linnaeus was the founder of
________________________ , the branch of
biology concerned with classifying organisms
• He developed the binomial format for naming
species (for example, Homo sapiens)
Descent with modification by natural
selection explains the adaptations of
organisms and the unity and diversity of life
• Some doubt about the permanence of species
preceded Darwin’s ideas
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The Voyage of the Beagle
• During his travels on the Beagle, Darwin collected
specimens of South American plants and animals
• He observed that fossils resembled living species
from the same region, and living species
resembled other species from nearby regions
• He experienced an earthquake in Chile and
observed the uplift of rocks
• Darwin was influenced by Lyell’s Principles of
Geology and thought that the earth was more than
6000 years old
• His interest in geographic distribution of species
was kindled by a stop at the Galápagos Islands
west of South America
• He hypothesized that _____________________
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
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Figure 22.5a
Great
Britain
EUROPE
NORTH
AMERICA
ATLANTIC
OCEAN
The
Galápagos
Islands
AFRICA
Equator
Chile
PACIFIC
OCEAN
Andes Mtns.
SOUTH
AMERICA
Malay Archipelago
PACIFIC
OCEAN
Brazil
AUSTRALIA
Cape of
Argentina Good Hope
Tasmania
New
Zealand
Cape Horn
Figure 22.5c
The
Galápagos
Islands
PACIFIC
OCEAN
Pinta
Genovesa
Marchena
Santiago
Fernandina
Isabela
0
20
40
Kilometers
Equator
Daphne
Islands
Pinzón
Santa Santa
Cruz
Fe
Florenza
San
Cristobal
Española
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Darwin’s Focus on Adaptation
• In reassessing his observations, Darwin
perceived ___________________________ to
the environment and the origin of new species
as closely related processes
• From studies made years after Darwin’s
voyage, biologists have concluded that this is
what happened to the Galápagos finches
Figure 22.6a
(a) Cactus-eater
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Figure 22.6b
(b) Insect-eater
Figure 22.6c
(c) Seed-eater
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• In 1844, Darwin wrote an essay on
__________________ _____________________
as the mechanism of descent with modification,
but did not introduce his theory publicly
• Natural selection is a process in which individuals
with favorable inherited traits are more likely to
survive and reproduce
• In June 1858, Darwin received a manuscript from
Alfred Russell Wallace, who had developed a
theory of natural selection similar to Darwin’s
• Darwin quickly finished The Origin of Species and
published it the next year
The Origin of Species
• Darwin explained three broad observations:
– ________________________________________
– ________________________________________
– ________________________________________
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Descent with Modification
• Darwin never used the word
________________________ in the first
edition of The Origin of Species
• The phrase ___________________________
___________________________________
summarized Darwin’s perception of the unity
of life
• The phrase refers to the view that all
organisms are related through descent from
an ancestor that lived in the remote past
• In the Darwinian view, the history of life is
like a tree with branches representing life’s
diversity
• Darwin’s theory meshed well with the
hierarchy of Linnaeus
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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, Natural Selection, and
Adaptation
• Darwin noted that humans have
____________________ other species by
selecting and breeding individuals with
desired traits, a process called
______________________ selection
• Darwin drew two inferences from two
observations
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Figure 22.9
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: ___________________________
________________________________________
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• Observation #2: All species can produce _______
________________________________________
________________________________________
________________________________________
________________________________________
________________________________________
• Inference #1: Individuals whose inherited traits
give them a higher probability of
______________________and
________________________ in a given
environment tend to
______________________________________
______________________________________
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• Inference #2: This _________________
ability of individuals to survive and reproduce
will lead to ___________________________
____________________________________
____________________________________
____________________________________
• Darwin was influenced by Thomas Malthus,
who noted the potential for human population
to increase faster than food supplies and
other resources
• If some heritable traits are
_________________________________,
these will accumulate in a population over
time, and this will increase the frequency of
individuals with these traits
• This process explains the match between
organisms and their environment
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• Note that _________________________ do
not evolve; _____________________ evolve
over time
• Natural selection can only increase or
decrease heritable traits that vary in a
population
• Adaptations vary with different environments
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
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Figure 22.UN02
Observations
Inferences
and
Figure 22.12a
(a) A flower mantid in Malaysia
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Figure 22.12b
(b) A leaf mantid in Borneo
Evolution is supported by an overwhelming
amount of scientific evidence
• New discoveries continue to fill the gaps
identified by Darwin in The Origin of Species
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Direct Observations of Evolutionary Change
• Two examples provide evidence for natural
selection: natural selection in response to
introduced plant species, and the evolution
of drug-resistant bacteria
Natural Selection in Response to Introduced
Plant Species
• Soapberry bugs use their “beak” to feed on
seeds within fruits
• In southern Florida soapberry bugs feed on
balloon vine with larger fruit; they have longer
beaks
• In central Florida they feed on goldenrain tree
with smaller fruit; they have shorter beaks
• Correlation between fruit size and beak size has
also been observed in Louisiana, Oklahoma, and
Australia
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• In all cases, beak size has evolved in
populations that feed on introduced plants
with fruits that are smaller or larger than the
native fruits
• These cases are examples of evolution by
natural selection
• In Florida this evolution in beak size occurred
in less than 35 years
Figure 22.13a
Soapberry bug with beak
inserted in balloon vine fruit
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Figure 22.13b
RESULTS
Beak
10
On native species,
southern Florida
8
Number of individuals
6
4
2
0
Museum-specimen average
10
On introduced species,
central Florida
8
6
4
2
0
6
7
8
9
Beak length (mm)
10
11
The Evolution of Drug-Resistant Bacteria
• The bacterium Staphylococcus aureus is
commonly found on people
• One strain, methicillin-resistant S. aureus
(MRSA) is a dangerous pathogen
• S. aureus became resistant to penicillin in
1945, two years after it was first widely used
• S. aureus became resistant to methicillin in
1961, two years after it was first widely used
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• Methicillin works by inhibiting a protein used by
bacteria in their cell walls
• MRSA bacteria use a different protein in their
cell walls
• When exposed to methicillin, MRSA strains are
more likely to survive and reproduce than
nonresistant S. aureus strains
• MRSA strains are now resistant to many
antibiotics
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
1,000,000
1,750,000
1,500,000
1,250,000
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• Natural selection does not ______________ new
traits, but _______________________ for traits
_________________________________ in the
population
• The local environment determines which traits will
be selected for or selected against in any specific
population
Other Evidence of Evolution
• ____________________________
• ____________________________
• ____________________________
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Anatomical and Molecular Homologies
• ___________________________ is similarity
resulting from common ancestry
• Homologous structures are anatomical
resemblances that represent
________________________ on a structural
theme present in a common ancestor
• Comparative embryology reveals anatomical
homologies not visible in adult organisms
• Examples of homologies at the molecular level are
genes shared among organisms inherited from a
common ancestor
Figure 22.15
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanges
Human
Cat
Whale
Bat
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Figure 22.16
Pharyngeal
pouches
Post-anal
tail
Chick embryo (LM)
Human embryo
Homologies and “Tree Thinking”
• Evolutionary trees are hypotheses about the
relationships among different groups
• Evolutionary trees can be made using different
types of data, for example,
_____________________________________
_____________________________________
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Figure 22.17
Branch point
Lungfishes
Amniotes
2
Digitbearing
limbs
Amnion
Mammals
Lizards
and snakes
3
4
Homologous
characteristic
Tetrapods
Amphibians
1
Crocodiles
Ostriches
6
Feathers
Birds
5
Hawks and
other birds
A Different Cause of Resemblance:
Convergent Evolution
• Convergent evolution is the evolution of
similar, or ______________________,
features in distantly related groups
• Analogous traits arise when groups
____________________________ adapt to
_________________________ environments
in similar ways
• Convergent evolution does not provide
information about _____________________
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Figure 22.18
NORTH
AMERICA
Sugar
glider
AUSTRALIA
Flying
squirrel
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
– For example,
____________________________________
____________________________________
____________________________________
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Figure 22.20
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
39