All These Sophisticated Attacks, Can We Really Detect Them - PDF
Evolution Produces Biodiversity
1.
2. “Evolve” Means to Change Over Time
The notion that life on Earth has changed
over time is quite old
To be considered science, this notion requires
a great deal of evidence
3. The Development of Evolutionary Theory
Naturalists have always wondered at the
diversity of living things………
Great varieties in shape, size, and ecological role
Estimated 3 million to 20 million different living
species
Much of the natural world’s biodiversity has vanished
through extinction
99% of all species that ever lived are now extinct
Permian-Triassic Mass Extinction
What Killed the Dinosaurs?
4.
5.
6.
7. Development of Evolutionary Theory
What could cause such great diversity, and
why have so many species died out?
Charles Darwin offered an explanation based on
careful observations
Who was Charles Darwin?
8.
9.
10.
11. Development of Evolutionary Theory
Darwin Concluded:
Physical traits and behaviors enable organisms
to survive and reproduce (called Fitness )
Fitness results from adaptations
Structural (body structures)
Behavioral (protection, predation, mating, etc.)
Functional (chemicals produced by the organism
that perform special functions)
12.
13. Development of Evolutionary Theory
Darwin reasoned that adaptations result from
natural selection and result in evolution
Evolution is the process by which living things
change and diversify over time
14. Development of Evolutionary Theory
These ideas were widely challenged
until a tremendous amount of evidence
was gathered to support evolution!
Now…The Theory of Evolution is the
Cornerstone of Biology
Explore the Evolution Revolution
16. Charles Darwin
Studied Medicine and Theology
Excelled in Geology and Biology
In 1831 Darwin joined the H.M.S.
Beagle on a trip around the world to
make maps
He was the ship’s naturalist
Darwin’s Diary
17. Darwin Pieces Together the Puzzle
Darwin traveled South America & Galapagos
Islands
Collecting fossils and other specimens
Making detailed observations of animal behavior
Making detailed drawings of the organisms he encountered
18. The Voyage of the Beagle: Ports of Call
Noted that populations of
organisms were slightly
different from place to
place
Each group was modified
to their specific
environment
25. Darwin Pieces Together the Puzzle
Author of “Principles of
Charles Lyell Geology”
This book helped Darwin realize
that the earth is old and changes
slowly over time.
26. Darwin Pieces Together the Puzzle
Thomas Malthus
Malthus wrote “Essay on
the Principles of Population”
Populations will always grow larger
than the food supply, creating hunger,
disease and struggle/competition.
Some people live, others die.
18th Century Economist
27. Darwin Pieces Together the Puzzle
Darwin coined the term Artificial Selection
- the process of modification of a species through
human actions which encourage the breeding of
certain traits over others.
http://www.esp.org/books/darwin/variation/facsimile/title3.html
28. Darwin Pieces Together the Puzzle
What Darwin Learned from Artificial Selection
When chosen organisms are mated, desired
characteristics are formed (Darwin didn’t know
about DNA)
Individuals in the wild who possess characteristics
that make it more likely for them to reproduce will
pass along these characteristics to their offspring.
“Desirable" characteristics, in the wild, would be
those which enhance survivability, NOT those which
specifically satisfy human needs. Nature does the
selecting.
29. Darwin Pieces Together the Puzzle
Lamarck’s View of Evolution
Stated that acquired characteristics
can be passed on to offspring.
30. Darwin Pieces Together the Puzzle
Darwin’s View of Evolution
Those giraffes with
longer necks got more
food and were better
able to survive to
reproduce, passing on
the long-neck genes to
their offspring. Over
time, giraffes evolved
longer necks.
31.
32. 4 Key Ideas of Natural Selection
“Of course, long before you
mature, most of you will be
eaten.”
33. Natural Selection
Evolution Through Natural Selection
Variation (genetic) is present in the
population and this variation is inherited
(genetically passed to offspring).
(Praying Mantis Camouflage)
Living things Overproduce
Competition for Limited Resources
Survival of the “Fittest”
Reluctantly published On the Origin of Species
in 1859
Video
34. Natural Selection
4 Main Points of Natural Selection
Variation (genetic) is present in the
population and this variation is inherited
(genetically passed to offspring).
Living things Overproduce
Competition for Limited Resources
Survival of the “Fittest” Video
35.
36. The Fittest Survive
Fitness Defined
Organisms who better survive to produce
larger numbers of offspring are considered
more fit than others who do not.
37. Darwin Today…
Natural Selection in action…
causes a
frequency
of certain
alleles in a
population
to increase
or decrease
over time!
38.
39.
40. Click the Link Below to Access the Cartoon
http://evolution.berkeley.edu/evolibrary/artic
Read the cartoon carefully and answer
the discussion questions on a separate
sheet of paper.
42. Speciation
Natural Selection modifies populations.
Some evolutionary changes are so great
that some organisms can no longer
interbreed with the original population
A new species results
Species
An interbreeding population of organisms
that can produce healthy, fertile offspring
43. Reproductive Barriers and Speciation
Prezygotic: gametes never meet and fuse
Geographic isolation (allopatric speciation)
Ecological isolation
Behavioral isolation (lacewing songs)
Mechanical isolation
Seasonal isolation
Postzygotic: genetic differences manifest
Hybrid inviability
Hybrid sterility (tigons and ligers)
49. Mechanical Isolation
Mating/Pollination is often impossible
between different animal/plant species
because of the incompatible shape and
size of the reproductive structures.
Size Does Matter!
Example – Black and White Sage Plants
50.
51. Black sage and white sage plants
invite different pollinators
White sage flowers have large landing platforms for large pollinators causing the
large pollinators to brush against the stamens, but the small ones usually don’t.
Black sage flowers have small landing platform for small pollinators. Therefore,
the small pollinators cannot spread pollen to the white sage flowers therefore
cross pollination is no longer possible.
52. Ecological Isolation
Two populations live
in different habitats
and mating occurs in
those habitats, thus
their own gene pool.
Land Iguana
Marine Iguana
53. After Mating Genetic Differences Occur
Hybrid sterility (tigons and ligers)
(Horse and a donkey = mule – sterile)
54. Patterns in Evolution
Adaptive Radiation (Divergence)
Development of numerous new species from a
common ancestor in diverse environments
Darwin’s Finches (Origin of Species Activity)
56. Pages to turn in:
63
107-109 #1-31
131
137
139
These assignments will calculate towards the 4th quarter
grade.
Once these are turned in you may work on the EC assignment
65. Taxonomy
Classification and naming of organisms
7 Taxonomic Groupings from most inclusive to most
specific:
• Kingdom “Kings play chess on fine green silk”
• Phylum
• Class
• Order
• Family
• Genus
• Species
66. Linnean Taxonomy
Carolus Linnaeus (1707-1778)
Binomial nomenclature (2 name naming)
Genus and species to make the scientific
name
Provides a common name that can be
used by all biologists regardless of their
native language.
67. Linnean Taxonomy
Example: human vs. chimpanzee
• Kingdom animalia animalia
• Phylum chordata chordata
• Class mammalia mammalia
• Order primata primata
• Family hominidae hominidae
• Genus homo pan
• Species sapiens troglodytes
• Homo sapiens and Pan troglodytes
• Classification activity
68.
69. Scientists from many disciplines including
biology, chemistry, physics, geology, and
paleontology have contributed to the case
for evolution!
The Origin of Life
Geology
The Fossil Record
Comparative Embryology
Comparative Biochemistry
Comparative Anatomy
Isn’t Evolution Just a Theory?
72. Early Earth
Evolution Starts Up: Chemical Evolution
Heterotroph Hypothesis: Molecules of life arose from inorganic building
blocks
73. The Miller-Urey Experiment
Studied Molecules Present at Time of
Early Earth
Methane, Ammonia, Carbon Dioxide,
Water Vapor
Mixed Molecules in Reaction Chamber
Sparked with Electricity to Simulate
Lightning
Exposed Mixture to UV Radiation to
Simulate Cosmic Rays
Produced Basic Amino Acids and Organic
Molecules
76. Biological Evolution
RNA as a information molecule and catalyst
Endosymbiotic Theory
Mitochondria and chloroplasts were
originally free living prokaryotic cells
Both have own DNA and ribosomes
Joined together to cooperate
77. Geology
The Study of the Earth and Rocks
Early Ideas About Earth:
People believed Earth was only a few thousand years old
People believed that rocks and geological features were
shaped by catastrophic events and rarely changed
79. Geology
In the 18th and 19th Century Scientists Studied
Geology in Great Detail
Old Earth, Ancient Life: Georges-Louis Leclerc,
Comte de Buffon (1749)
81. Charles Lyell: The Principles of Geology
Earth is Changed by
Weather and Natural
Processes like Volcanoes and
Erosion
Takes a Very Long Time!
Gradualism and
Uniformitarrianism
82.
83.
84. Continental Drift
• Over millions of
years 1 original
continent Pangea
drifted apart to
make our
modern
continents
• Continental drift
is gradual
“gradualism”
89. Geology
These ideas refute the idea that the Earth is
only a few thousand years old
Provides long time necessary for evolution
Backed up by radiometric dating
The Earth is approximately 4.6 Billion Years Old
4,600,000,000 years is a long time!
92. The Fossil Record
Fossils are the preserved remains of
ancient organisms
Provide information about past
organisms
Shows that many diverse organisms
lived at different times in Earth’s
History
94. The Fossil
Record
Provide a record of past species
Important source of information for
determining ancestry and patterns of evolution
Fossil
Archaeopteryx
95. What does the fossil
record tell us?
•What past life looked like
•What past habitats were like
and changes that have occurred
•That diverse organisms
lived on earth at different times
•New species evolved
•Some species became extinct
•Earliest life forms were aquatic
•Earliest life forms were simple
in structure
http://www.pbs.org/wgbh/evolution/library/04/3/quicktime/l_043_01.html
97. The Fossil Record
Taphonomy: The Formation of Fossils
Fossils form in sedimentary rock
Dead organisms covered by sand and silt
Sediments are passed into bone by
pressure from above (fossils form in
sedimentary rock)
Video
98.
99. Determining the Age of Fossils
Relative Dating: Technique used by
scientists to determine the age of fossils
relative to fossils in other layers of rock
Different layers represent different geologic
periods
Older fossils found in lower layers, newer
fossils found in upper layers
Cannot determine the actual age of the
fossil!
100.
101.
102. Determining the Age of Fossils
Radioactive Dating: Process by which traces of
radioactive elements are analyzed to calculate the
actual age of a fossil
Many radioactive elements can be used as geologic
clocks. Each radioactive element decays at its own
nearly constant rate. Once this rate is known,
geologists can estimate the length of time over
which decay has been occurring by measuring the
amount of radioactive parent element and the
amount of stable daughter elements
Video
103. Radioactive/Radiometric Dating
How it Works:
- radioactive elements (uranium,
Carbon14) break down/decay a
specific rates = half life
- these rates are nearly constant
- the amount of radioactive decay that
has taken place in a rock/fossil determines
its age
104. Scientist Measure the Age of the Earth
Radiometric Dating: way of estimating the age of the
Earth!
http://www.pbs.org/wgbh/evolution/library/03/3/quicktime/l_033_01.html
105. 5,700 year is
C14 half-life
Carbon-14 Dating
- Determines the age of
fossils of a biological
origin up to approx.
50,000 years old.
- used in dating things
such as bone, cloth,
wood, plant fibers, etc.
109. Radiometric Dating
Radioactive Stable
Half life
Parent Daughter
1.25 billion
Potassium 40 Argon 40
yrs
Strontium 48.8 billion
Rubidium 87
87 yrs
14 billion
Thorium 232 Lead 208
years
704 million
Uranium 235 Lead 207
years
4.47 billion
Uranium 238 Lead 206
years
Carbon 14 Nitrogen 14 5730 years
110. The Geologic Time Scale
Based on fossil and geologic evidence
A record of the Earth’s past
Divided into Era, Period, and Epoch
Shows that life on Earth followed geologic
change on Earth
Deep Time Activity
Interactive Time Scale
113. Comparative Embryology
All vertebrate embryos,
including humans, share
features
Eye spot
• (Evolution of the Human Eye)
Gill pouches
Notochord
Shows similar genetic
ancestry
Video
114. Comparative Biochemistry
All life is based on organic chemistry
Carbon based compounds
All life uses same molecule as blueprint
DNA
Similar chemical processes
Bacteria, algae, and plants all do photosynthesis
Similar organisms have similar genetic code
Humans and chimpanzees share nearly identical
genes (98.4% identical gene sequences) Video
115. Anatomy and Comparative Anatomy
Vestigial Organs
Organs inherited but not used by modern
organisms
Present but greatly reduced in modern
organisms
Hip bone in python
Appendix in human
Tail bone (cocyx) in human
116. Anatomy: Homologous Structures
Similar parts of different organisms,
often quite dissimilar in purpose, that
developed from the same ancestral
body parts (Video)
Divergent evolution
117. Anatomy: Analogous Structures
Similar in purpose, but not inherited
from a recent common ancestor
Environment selected for trait
Wings of birds and insects
Convergent evolution
118. Summary
There is overwhelming evidence to
support the Theory of Evolution
Evidence comes from disciplines as
varied as biology, geology, chemistry,
physics, astronomy, and paleontology
Evolution has produced the great
beauty and diversity of life on Earth
over the last 4 billion years
120. Explore Human Evolution
View the Becoming Human broadband
documentary
As you view each segment, visit the related
exhibits to further explore this topic
Go to the Learning Center and select the
“Calculating Cousins” activity
Go to the Learning Center and select the
“Chromosome Connection” activity
Go to the Learning Center and select the
“Building Bodies” activity
121. The Order Primate
Characteristics of Primates
Strong hands and opposable thumbs
Free-moving shoulder joint
Forward facing eyes and stereoscopic vision
Intelligence/larger brain
Social complexity
122. What Characteristics do Humans Have?
All of those of primates, plus
Upright posture and bipedal
Use of tools and technology
Advanced intelligence
Complex communication and speech
123. The Steps to Human Evolution
Terrestrialization
Bipedal (Walking on all two’s)
Increased Brain Size
Civilization
Take a look at the Human family tree
124. The Hominid Family
Each year new fossils are found to add
to the Hominid family tree
Most fossils of early humans are found
in Africa and lower Asia
Most well understood members include
genus Australopithecus (extinct) and
genus Homo
Solve the Riddle of the Bones
125. Genus Australopithecus
First human ancestor to live on the
ground and walk on two legs
As evidenced by the Laetoli footprints
Ape-like jaw
Small brain
Short stature
Found only in South and East Africa
126. The Australopithecines
A. anamesis 4 MYA
A. afarensis 3.2 MYA (Finding “Lucy”)
A. africanus 2.5 MYA
A. robustus 2 MYA
A. boisei 2 MYA
127. Genus Homo
More modern hominids that exhibited major
evolutionary steps
Increased brain size
Use of tools
Use of fire
Use of shelter
Religion
Language and civilization
128. Homo habilis “The Tool Man”
Approx. 2.5 MYA
Brain ½ size of
modern human
First to make and use
stone tools and
weapons
129. Homo erectus “The Upright Man”
Direct ancestor of
modern humans
Widespread in Africa
and Asia by 1 MYA
Evidence of use of
shelter and fire
130. Homo sapiens “The Wise Man”
Most likely evolved from H. erectus as early
as 400,000 years ago
Greatly increased brain size
Consisted of 2 groups
Neanderthal
Cro-Magnon/modern H. sapiens
131. Neanderthals
Found in Neander Valley in Germany
Fossils found throughout Europe, Middle
East, and Asia from 150,000-30,000
years ago
Large bodies and brains
Evidenced painting, religion, complex
social structure
“Cave man”
132. Cro Magnons and Fully Modern Humans
First early modern H. sapiens appear about
130,000 years ago
Thinner bones, smaller jaws, higher skull
with little or no brow ridge, and larger brains
Cave art shows complex religion and culture
Lived alongside Neanderthal for several
thousand years, but eventually out-competed
them
