1. Attendance
2. Tests: Shantese, Jamila, Lakota
3. I have storybooks from: Heather,
Julisa, Mawazo, Destiny, Calisa,
Shantese
4. I have Finch labs
from:Shantese,Trev, Iesha, Jamila,
Samiyah, Naima, Calisa, Lakota,
Julisa, Mawazo, Destiny
Genetic Engineering
 Genetic Engineers can alter
the DNA code of living
organisms.
 Selective Breeding
 Recombinant DNA
 PCR
 Gel Electrophoresis
 Transgenic Organisms
Selective Breeding
 Breed only those plants
or animals with desirable
traits
 People have been using
selective breeding for
1000’s of years with farm
crops and domesticated
animals.
Recombinant DNA
 The ability to combine
the DNA of one
organism with the DNA
of another organism.
 Recombinant DNA
technology was first used
in the 1970’s with
bacteria.
1.
Recombinant Bacteria
Remove bacterial DNA (plasmid).
2.
Cut the Bacterial DNA with
“restriction enzymes”.
3.
Cut the DNA from another
organism with “restriction
enzymes”.
4.
Combine the cut pieces of DNA
together with another enzyme
and insert them into bacteria.
5.
Reproduce the recombinant
bacteria.
6.
The foreign genes will be
expressed in the bacteria.
Benefits of Recombinant Bacteria
1.
Bacteria can make human insulin or human growth
hormone.
1.
Bacteria can be engineered to “eat” oil spills.
The DNA of plants and animals
can also be altered.
PLANTS
1.
disease-resistant and
insect-resistant crops
2. Hardier fruit
3. 70-75% of food in
supermarket is
genetically modified.
How to Create a Genetically
Modified Plant
1.Create recombinant
bacteria with desired
gene.
2. Allow the bacteria to
“infect" the plant cells.
3. Desired gene is inserted
into plant chromosomes.
What do you think about eating genetically
modified foods?
Genetically modified organisms are called
transgenic organisms.
TRANSGENIC ANIMALS
1.
Mice – used to study human
immune system
2.
Chickens – more resistant to
infections
3.
Cows – increase milk supply
and leaner meat
4. Goats, sheep and pigs –
produce human proteins in
their milk
Transgenic Goat
Human DNA in
a Goat Cell
.
This goat contains a human gene
that codes for a blood clotting
agent. The blood clotting agent
can be harvested in the goat’s
milk.
How to Create a
Transgenic Animal
Desired DNA is
added to an egg cell.
Ha Ha Ha!
Genetic Engineering and
Crime Scenes……
Gel Electrophoresis
 This technology allows
scientists to identify
someone’s DNA!
Steps Involved in Gel Electrophoresis
1. “Cut” DNA sample with
restriction enzymes.
2. Run the DNA fragments
through a gel.
3. Bands will form in the gel.
4. Everyone’s DNA bands are
unique and can be used to
identify a person.
5. DNA bands are like “genetic
fingerprints”.
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EVOLUTION
Chapter 15
Charles Darwin
Question for Thought
Earth has millions of other kinds of
organisms of every
imaginable shape, size, and habitat.
This variety of living things is called
biological
diversity. How did all these different
organisms arise?

How are they related?

In your own words, describe
what YOU think the theory of
evolution means…
Darwin’s Theory of Evolution

Evolution, or change over time, is the
process by which modern organisms have
descended from ancient organisms.

A scientific theory is a well-supported
testable explanation of phenomena that have
occurred in the natural world.
How do you think Darwin came
up with his theory?
Voyage of the Beagle
Voyage of Beagle
Dates: February 12th, 1831
 Captain: Charles Darwin
 Ship: H.M.S. Beagle
 Destination: Voyage around the world.
 Findings: evidence to propose a
revolutionary hypothesis about how life
changes over time

Patterns of Diversity

Darwin visited Argentina and Australia which had
similar grassland ecosystems.

those grasslands were inhabited by very different
animals.

neither Argentina nor Australia was home to the
sorts of animals that lived in European grasslands.
Patterns of Diversity

Darwin posed challenging questions.
 Why were there no rabbits in Australia, despite the
presence of habitats that seemed perfect for them?

Why were there no kangaroos in England?
Living Organisms and Fossils

Darwin collected the preserved remains of
ancient organisms, called fossils.

Some of those fossils resembled organisms that
were still alive today.
Living Organisms and Fossils

Others looked completely unlike any creature he had
ever seen.

As Darwin studied fossils, new questions arose.
 Why had so many of these species disappeared?

How were they related to living species?
Fossils
The Galapagos Island

The smallest, lowest islands were hot,
dry, and nearly barren-Hood Island-sparse
vegetation

The higher islands had greater rainfall and
a different assortment of plants and
animals-Isabela- Island had rich
vegetation.
The Galapagos Island

Darwin was fascinated in particular by the land
tortoises and marine iguanas in the Galápagos.

Giant tortoises varied in predictable ways from
one island to another.

The shape of a tortoise's shell could be used to
identify which island a particular tortoise
inhabited.
Animals found in the Galapagos

Land Tortoises

Darwin Finches

Blue-Footed Booby

Marine Iguanas
Animals
The Journey Home
 Darwin
Observed that characteristics
of many plants and animals vary
greatly among the islands
 Hypothesis:
Separate species may
have arose from an original ancestor
Ideas that shaped Darwin’s
Thinking

James Hutton:

1795 Theory of
Geological change
 Forces change
earth’s surface
shape
 Changes are slow
 Earth much older
than thousands of
years
Ideas that Shaped Darwin’s
Thinking

Charles Lyell

Book: Principles of
Geography
Geographical features
can be built up or torn
down
Darwin thought if
earth changed over
time, what about life?


Lamarck
Lamarck’s Theory of Evolution

Tendency toward Perfection(Giraffe
necks)

Use and Disuse (bird’s using forearms)

Inheritance of Acquired Traits
Are you still paying Attention?

Population Growth


Thomas Malthus19th century English
economist
If population grew
(more Babies born
than die)
 Insufficient living
space
 Food runs out
 Darwin applied this
theory to animals
Publication of Orgin of Species

Russel Wallace wrote
an essay summarizing
evolutionary change
from his field work in
Malaysia

Gave Darwin the drive
to publish his findings
Natural Selection & Artificial
Selection

Natural variation--differences among
individuals of a species

Artificial selection- nature provides the
variation among different organisms, and
humans select those variations they find
useful.
Evolution by Natural Selection

The Struggle for Existence-members of
each species have to compete for food,
shelter, other life necessities

Survival of the Fittest-Some individuals
better suited for the environment
Struggle For Existence &
Survival of The Fittest
Natural Selection

Over time, natural
selection results in
changes in inherited
characteristics of a
population. These
changes increase a
species fitness in its
environment
Descent


Descent with Modification-Each living organism has
descended, with changes from other species over time
Common Descent- were derived from common ancestors
Evidence of Evolution

The Fossil Record

Geographic Distribution of Living Things

Homologous Body Structures

Similarities in Early Development
Evidence for Evolution




The Fossil RecordLayer show change
Geographic
Distribution of Living
Things
Homologous Body
Structures
Similarities in Early
Development
Evidence of Evolution




The Fossil Record
Geographic
Distribution of
Living Things-similar
environments have
similar types of
organisms
Homologous Body
Structures
Similarities in Early
Development
Homologous Structures
 Homologous
Structures-structures that
have different mature forms in different
organisms, but develop from the same
embryonic tissue
Evidence for Evolution
 Vestigial
organs-organs that serve
no useful function in an organism
 i.e.) appendix, miniature legs, arms
Similarities in Early
Development
Summary of Darwin’s Theory

Individuals in nature differ from one
another

Organisms in nature produce more offspring
than can survive, and many of those who do
not survive do not reproduce.
Summary of Darwin’s Theory

Because more organisms are produce than
can survive, each species must struggle for
resources

Each organism is unique, each has
advantages and disadvantages in the
struggle for existence
Summary (cont.)

Individuals best suited for the environment
survive and reproduce most successful

Species change over time
Summary (cont.)

Species alive today descended with modification
from species that lived in the past

All organisms on earth are united into a single
family tree of life by common descent
Darwin & Evolution
by
Natural Selection
Cactus
eater
Insect eaters
Seed eaters
Bud eater
Regents Biology
2006-2007
Charles Darwin
 Proposed a way how
evolution works
How did creatures
change over time?
 by natural selection

 Collected a lot of
evidence to support
his ideas
1809-1882
 British naturalist

Regents Biology
Voyage of the HMS Beagle
 Invited to travel around the world
1831-1836 (22 years old!)
 makes many observations of nature

 main mission of the Beagle was to chart
South American coastline
Robert Fitzroy
Regents Biology
Voyage of the HMS Beagle
 Stopped in Galapagos Islands

500 miles off coast of Ecuador
Regents Biology
Galapagos
Recently formed volcanic
islands. Most of animals on
the Galápagos live nowhere
else in world, but they look
like species living on South
American mainland.
Regents Biology
800 km west of Ecuador
Darwin found…many unique species
Many of Darwin’s observations made
him wonder… Why?
Darwin asked:
Why were these creatures found only
on the Galapagos Islands?
Regents Biology
Darwin found…clues in the fossils
Darwin found:
Evidence that creatures
have changed over time
present day Armadillos
Darwin asked:
ancient Armadillo
Regents Biology
Why should extinct
armadillos & modern
armadillos be found on
same continent?
Darwin found:
Different shells on tortoises on different islands
Darwin asked:
Is there a relationship
between the environment
& what an animal
looks like?
Regents Biology
Darwin found… birds
Darwin found:
Many different birds
on the Galapagos
Islands.
He thought he found Finch?
very different kinds…
Regents Biology
Sparrow?
QuickTime™ and a
Photo - JPEG decompressor
are needed to see this picture.
Woodpecker?
Warbler?
But Darwin found… a lot of finches
Darwin was amazed to
find out:
All 14 species of birds
were finches…
But there is only one
species of finch on the
mainland!
Large
ground
Small
ground
Finch?
Sparrow?
Finch?
Sparrow?
QuickTime™ and a
- JPEG decompressor
finch arePhoto
finch
needed to see this picture.
Darwin asked:
If the Galapagos
finches came from the
mainland, why are they
so different now?
Regents Biology
Warbler finch
Woodpecker?
Woodpecker?
Tree
finch
Warbler?
Warbler?
The finches cinched
it!
 different beaks are
Darwin found:
The differences
between species of
finches were
associated with the
different food they
ate.
Regents Biology
inherited variations
 serve as adaptations
that help
birds said:
compete
Darwin
for food
Ahaaaa!
 these birds survive &
Aeater
flock of South
Big
Large
seed
ground
Small
Small
seed
ground
eater
Finch?
Sparrow?
reproduce
finch
finch
American finches
 pass on the genes for
were stranded on the
those more fit beaks
Galapagos…
 over time nature selected
for different species with
different beaks
QuickTime™ and a
Photo - JPEG decompressor
are needed to see this picture.
Warbler
Insect eater
finch
Woodpecker?
Leaf
Tree
& bud
finch
eater
Warbler?
Relationship between species (beaks) & food
Regents Biology
Darwin’s finches
 Darwin’s conclusions

variations in beaks
 differences in beaks in the original flock
 adaptations to foods available on islands

natural selection for most fit
 over many generations, the finches were
selected for specific beaks & behaviors

offspring inherit successful traits
 accumulation of winning traits:
both beaks & behaviors
separate into different species

Regents Biology
From 1 species to 14 species…
Warbler finch
Cactus finch
Woodpecker finch
Sharp-beaked finch
Small
insectivorous
tree finch
Large
insectivorous
tree finch
Small
ground
finch
Cactus
eater
Insect eaters
Seed eaters
Vegetarian
tree finch
variation
Regents Biology
Bud eater
Medium
ground
finch
Large
ground
finch
natural selection for best
survival & reproduction
Earlier ideas on Evolution
 LaMarck

evolution by acquired
traits
 creatures developed
traits during their lifetime
 give those traits to their
offspring

example
 in reaching higher
leaves giraffes stretch
their necks & give the
acquired longer neck to
offspring

not accepted as valid
Regents Biology
Darwin’s view of Evolution
 Darwin
giraffes that already
have long necks
survive better
 leave more offspring
who inherit their long
necks
 variation
 selection &

survival
 reproduction &
inheritance of
Regents Biologymore fit traits
Asking Questions
is a good adaptation!
Regents Biology
2006-2007
Darwin found… more fossils
Darwin found:
Evidence that creatures
have changed over time
present day Sloth
(extinct) Giant ground sloth
Darwin asked:
Regents Biology
Why should
extinct sloths &
modern sloths be
found on the same
continent?
Chapter 17
The History
of Life
Fossil imprint
The Fossil Record
• Provides evidence
about the history of
life on Earth.
• It also shows how
different groups of
organisms, including
species, have
changed over time.
Relative vs. Absolute Dating
Comparing Relative and Absolute Dating of Fossils
Can determine
Is performed by
Drawbacks
Relative Dating
Absolute Dating
Age of fossil with respect to
another rock or fossil (that is,
older or younger)
Age of a fossil in years
Comparing depth of a fossil’s
source stratum to the position
of a reference fossil or rock
Determining the relative
amounts of a radioactive
isotope and nonradioactive
isotope in a specimen
Imprecision and limitations of
age data
Difficulty of radioassay
laboratory methods
Principle of Superposition
• In an undisturbed sequence of
sedimentary rocks, the oldest rocks are on
the bottom with the most recent on top.
How fossils are formed
Water carries small rock
particles to lakes and seas.
Dead organisms are buried
by layers of sediment, which
forms new rock.
The preserved remains
may later be discovered
and studied.
Geological Time Scale
• After the Precambrian Time, the time scale
is divided into eras, which are subdivided
into periods.
Era
Period
(millions of
Time years ago)
Quaternary
1.8–present
Tertiary
65–1.8
Cretaceous
145–65
Jurassic
208–145
Triassic
245–208
Era
(millions of
Period
Time years ago)
Permian
290 – 245
Carboniferous
360–290
Devonian
410–360
Silurian
440–410
Ordovician
505–440
Cambrian
544–505
Era
(millions of
Period
Time years ago)
Vendian
650–544
Geological Time Scale
• The major eras are Paleozoic, Mesozoic,
and Cenozoic.
Era
Period
(millions of
Time years ago)
Quaternary
1.8–present
Tertiary
65–1.8
Cretaceous
145–65
Jurassic
208–145
Triassic
245–208
Era
(millions of
Period
Time years ago)
Permian
290 – 245
Carboniferous
360–290
Devonian
410–360
Silurian
440–410
Ordovician
505–440
Cambrian
544–505
Era
(millions of
Period
Time years ago)
Vendian
650–544
Geologic Time Scale
• Each period hosts significant evolutionary
changes to species diversity and
extinction.
Era
Period
(millions of
Time years ago)
Quaternary
1.8–present
Tertiary
65–1.8
Cretaceous
145–65
Jurassic
208–145
Triassic
245–208
Era
(millions of
Period
Time years ago)
Permian
290 – 245
Carboniferous
360–290
Devonian
410–360
Silurian
440–410
Ordovician
505–440
Cambrian
544–505
Era
(millions of
Period
Time years ago)
Vendian
650–544
Summary of major events
(pg. 429-34)
Era
Cenozoic
Mesozoic
Paleozoic
Precambrian
Time
Period
Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Time
(millions of
years ago)
1.8–present
65–1.8
145–65
208–145
245–208
290–245
363–290
410–363
440–410
505–440
544–505
650–544
Key Events
Glaciations; mammals increased; humans
Mammals diversified; grasses
Aquatic reptiles diversified; flowering plants; mass extinction
Dinosaurs diversified; birds
Dinosaurs; small mammals; cone-bearing plants
Reptiles diversified; seed plants; mass extinction
Reptiles; winged insects diversified; coal swamps
Fishes diversified; land vertebrates (primitive amphibians)
Land plants; land animals (arthropods)
Aquatic arthropods; mollusks; vertebrates (jawless fishes)
Marine invertebrates diversified; most animal phyla evolved
Anaerobic, then photosynthetic prokaryotes; eukaryotes,
then multicellular life
Hypothesis of early Earth
• Very hot surface from
colliding meteorites
• Very hot planet core
from radioactive
materials
• Volcanoes spewing
lava and gases that
helped to form the
early atmosphere
Hypothesis of early Earth
• About 4.4 billion years ago, Earth might
have cooled enough for the water in its
atmosphere to condense.
• This might have led to millions of years of
rainstorms with lightning, enough rain to fill
depressions that became Earth’s oceans.
• The oldest rocks dated are 3.9 million
years old.
Fossils: evidence of an organism that
lived long ago that is preserved in
Earth’s rocks
• Paleontologists
estimate that
about 95%
species are
extinct from
life’s origins.
• Climate and
ancient
geography can
be determined
from fossils.
Types of Fossils
Formation
Fossils Types
A trace fossil
is any
indirect
A trace
fossil
is anyevidence
indirect evidence
Trace fossils
left by an animal and may include a
footprint, a trail, or a burrow.
When minerals in rocks fill a space
left by a decayed organism, they make
a replica, or cast, of the organism.
Casts
Molds
A mold forms
when
an organism
is
A mold
forms
when an organism
is
Petrified/
Permineralized
fossils
AmberPreserved or
frozen fossils
buried in sediment and then decays,
leaving an empty space.
Petrified-minerals sometimes penetrate
and replace the hard parts of an
organism. Permineralized-void spaces
in original organism infilled by
minerals.
At times, an entire organism was
quickly trapped in ice or tree sap that
hardened into amber.
What has been learned from
fossils
• several episodes of mass extinction that
fall between time divisions
– mass extinction: an event that occurs when
many organisms disappear from the fossil
record almost at once
• The geologic time scale begins with the
formation of Earth about 4.6 billion years
ago.
Precambrian – 87% of history
• Oldest fossils about 3.4 billion years old
resembling cyanobacteria stromatolites.
• Stromatolites still form today in Australia
from mats of cyanobacteria.
• The stromatolites are evidence of the
existence of photosynthetic organisms on
Earth during the Precambrian.
• Only prokaryotic life found in fossil record
End of Precambrian – 543 MYA
• multicellular eukaryotes,
such as sponges and
jelly-fishes, diversified
and filled the oceans
Paleozoic and Cambrian Period
• Paleozoic Era: more animals and plants
– Early: fishes, aquatic vertebrates, ferns
– Middle: amphibians
– Late: reptiles and mass extinction
– Cambrian Period: oceans teemed with many
types of animals, including worms, sea stars,
and unusual arthropods
Mesozoic - 248 MYA
• Triassic Period: mammals and dinosaurs
• Jurassic Period: dinosaurs and birds
• Cretaceous Period: more mammals,
flowering plants, but mass extinction of
dinosaurs 65 MYA
Continental drift
• Earth’s continents have moved during
Earth’s history and are still moving today
at a rate of about six centimeters per year.
• The theory for how the continents move is
called plate tectonics.
Geologic Time Scale video
Click on image to play video.
Miller-Urey experiment showed one possible
way for inorganic molecules to form organic
molecules.
Mixture of gases
simulating
atmospheres of
early Earth
Spark simulating
lightning storms
Condensation
chamber
Water
vapor
Cold
water
cools
chamber,
causing
droplets
to form
Liquid containing
amino acids and
other organic
compounds
How eukaryotic cells evolved
• Lynn Margulis proposed the endosymbiotic
theory.
Chloroplast
Aerobic
bacteria
Ancient Prokaryotes
Nuclear
envelope
evolving
Plants and
plantlike
protists
Photosynthetic
bacteria
Mitochondrion
Primitive Photosynthetic
Eukaryote
Ancient Anaerobic
Prokaryote
Primitive Aerobic
Eukaryote
Animals, fungi, and
non-plantlike protists
Endosymbiotic theory
• Heterotrophic bacteria have plasmids
(DNA loop) & simple ribosomes in their
cytoplasm
• Mitochondria have circular DNA &
bacteria-like ribosomes
• So…Eukaryotic cells may have engulfed
prokaryotic cells & by mutualism created
the “first mitochondria.”
• Autotrophic bacteria are Cyanobacteria
with chlorophyll
• So, Eukaryotic cells may have engulfed
prokaryotic cyanobacteria & by mutualism
created the “first chloroplast.”
• Heterotrophic symbiosis = symbiont
produces ATP, host uses ATP, host
protects symbiont
• Autotrophic symbiosis = symbiont
produces sugar, host uses sugar,
host protects symbiont
• Relationships may allow host to live longer
& reproduce more, thus over time creating
more complex eukaryotic cells
Evolution of life video
Click on image to play video.
Macroevolution
 Large-scale evolutionary patterns and
processes that occur over long periods of time.
 Includes 6 topics:
Extinction
Adaptive radiation
Convergent evolution
Divergent evolution
Punctuated equilibrium
Changes in developmental genes
Patterns of evolution
• Darwin believed that
organisms evolved
gradually.
• Niles Eldredge and
Stephen Jay Gould
believed punctuated
equilibrium is how
organisms evolved,
periods of rapid
evolution followed by
periods of stasis.
Adaptive Radiation
• Single species or small groups of species
evolved into diverse forms living in different
ways.
Convergent Evolution
• Adaptive radiation can produce unrelated
organisms that look similar due to similar
environments.
Coevolution
The process by which
two species evolve in
response to changes in
each, other over time.
http://ecology.botany.ufl.edu/ ecologyf02
• Example: “This butterfly
acquires a cardiac
glycoside from members
of the genus Asclepias.
Because of their milky
sap, these are commonly
referred to as milkweed
plants. The plants
produce this toxin as a
defense against
herbivory, but the
Monarch has the ability to
sequester the toxin in
fatty tissues so that it
makes the butterfly
unpalatable while not
poisoning the butterfly.”