Class Expectations: The Warrior Creed
• Be Respectful
– Listen when the
teacher or others are talking
– Raise your hand when
you wish to contribute to class discussions
– No cross-room
conversations
Class Expectations: Warrior Creed
• Be Responsible
– Keep locker and
notebooks organized
– Avoid distraction
– Stay focused on task
completion
– Turn in homework
assignments on time
Class Expectations: The Warrior Creed
• Be Ready To Learn
– Attend class regularly
– Do your best
– Never give up
– Getting a strong education gets you closer to your hopes and dreams
BLUE SLIDES: COPY NOTES
• Notes should be neatly written
• Use indentations when appropriate
– Example of indent
• Skip a line between topics
• Make visuals clear and well drawn
Resistance
arm Effort arm
Darwin’s Journey
•HMS Beagle – set sail in
1831
•Darwin was ship’s naturalist •He observed plants and
animals he had never seen before.
•Darwin noticed the diversity
Four Parts of Darwin’s Theory
1. Organisms have changed over time
• Organisms living today are different from those that
lived in the past
• Many organisms that once lived are now extinct. • The world is not constant but changing (fossil
record)
• All organisms are derived from common ancestors
by a process of branching
– Populations split into different species, which are related
3. Change is a slow process over many
generations
• Punctuated evolution: sometimes change
speeds up
4. Mechanism of Evolutionary Change Was
Natural Selection
• Organisms best suited to their environment
Galapagos Organisms: Comparison to South
American Organisms
•Darwin found similarities
between Galapagos organisms and those in South America
•He noticed differences
between the island organisms and those in South America.
Galapagos Organisms: Comparison Among the Islands
•Darwin notices many
differences among the
organisms from one island to the next.
•Dome-shaped tortoise vs.
Galapagos Organisms: Adaptations
•Adaptation: trait that
helps an organism to survive and
reproduce.
•Beaks of finches help
them obtain food:
•Narrow beak:
eating insects
•Wide beak: eating
Galapagos Organisms: Adaptations
•Speciation: when one
species evolves into 2 separate species.
•It is considered a
new species when they can no longer interbreed and
Adaptive Radiation
• Adaptive Radiation: process by which a
species evolve so that they are adapted to their environment.
– Darwin’s finches
Evolution: Darwin’s Reasoning
•He reasoned that plants or animals that arrived on the
Galapagos Islands faced conditions that were different from those on the mainland.
•Evolution: gradual change in a species over time.
•Darwin concluded that organisms on the Galapagos Islands
Natural Selection
•Natural selection is the
process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.
•The variety of organisms on
Evolution: change of a population of
organisms from one generation to the next.
• Example of Evolution -The Samurai Crab.
• The Samurai Crab didn’t always look like a
samurai.
• The Samurai Crab didn’t always look like a
samurai.
– Every so often, one crab looked a little more like a
samurai.
• The Samurai is revered in Japan.
• The Samurai is revered in Japan.
– When fisherman caught a crab that looked like a
Samurai they believed it was the reincarnation of a samurai warrior.
• The Samurai is revered in Japan.
– When fisherman caught a crab that looked like a
Samurai they believed it was the reincarnation of a samurai warrior.
– They were thrown back into the sea.
• Over many generations, the crabs that looked
slightly more like a Samurai reproduced more often than those that did not.
• Over many generations, the crabs that looked
slightly more like a Samurai reproduced more often than those that did not.
– Their young looked like samurai.
• Overtime, the shell of these crabs began looking
more and more like a Samurai, because those that looked like a Samurai survived to reproduce.
– This is one example of how selection leads to changes.
• Overtime, the shell of these crabs began looking
more and more like a Samurai, because those that looked like a Samurai survived to reproduce.
– This is one example of how selection leads to changes.
“Don’t mess with
me, I’m a crab on
Factors that Affect Natural Selection
• Variations: any difference between individuals
• Yeah! Baby Animal Time.
• Competition: members of a species compete
• Selection: Environment has selected
• Environmental Change: a change in
• Genes and Natural Selection
• Only traits that are inherited by genes can be
• Overproduction: most species produce far
• So what is going to happen to most of these
tadpoles?
“Ahhhh!”
“Carnivorous
“Oh no!”
“Hey, I
made it to
“Anyone out
there.”
“We’re suppose to be
on the same team
“Bats!”
“Ouch!”
“That left
more than
“Frogs legs!”
“I’m ending up
• Maybe two of those 20,000 eggs in a good
1. Fossil Record
• Changes in plants and
animals over millions of years.
• By examining fossils,
scientists infer the structures of ancient organisms.
• Fossils show that
2. Similarities in Embryonic Development
• Comparative Embryology
• similarities in organisms when we compare embryos. • Embryos of different species are often similar even
3. Similarities in Body Structure
• Comparative Anatomy
• Homologous
Structures – similar structures that
related species have inherited from a
common ancestor
• supported by fossil
5. Genetics
• Shows how organisms have evolved and are related
on a genetic level
• Scientists looks at genes in a DNA molecule.
• The hypotheticus is a normal animal, it eats
leaves and tubers (roots).
• The hypotheticus is a normal animal, it eats
leaves and tubers (roots). A male hypotheticus meets a female.
• More babies are born than can possibly
survive.
• Each Hypotheticus is slightly different than the
other.
• Predators such the Fanged Tooth
Scienceteachericus kept populations of the Hypotheticus in check.
• One of the offspring has more hair than most.
The hairy Hypotheticus.
• One of the offspring has a slightly larger neck.
The long neck Hypotheticus.
• Climate in hypotheticus land became
drastically dry for the next several years.
Many of the shrubs are eaten or start to die.
• Natural Resources are limited for the normal
Hyptheticus.
• The normal Hypotheticus can’t reach the
leaves, and there aren’t enough shrubs to
survive. Normal hypotheticus have a difficult time surviving. Tuber roots just below the
surface are eaten quickly.
• Over thousands of years, the normal type
hypotheticus slowly have trouble surviving to reproduce.
• The long necked Hypotheticus tend to survive
more often because they can reach leaves on trees.
• With more long necked Hypotheticus
surviving, long necked Hypotheticus tend to mate with long necked Hypotheticus over millions of years.
• Overtime, nature favors long necked
Hypotheticus, and gradually, those offspring with longer necks survive more often to
reproduce and their offspring have long necks.
• Overtime, nature favors long necked
Hypotheticus, and gradually, those offspring with longer necks survive more often to
reproduce and their offspring have long necks.
1. Similarities in DNA (biochemistry)
•Scientists infer that
species have inherited many of the same genes from a common ancestor.
•Compare genes to see
how closely related certain organisms are
•compare the
sequence of nitrogen bases.
•compare the order of
2. Comparing Evidence
•Evidence from DNA and
protein structure confirms most conclusions based on fossils, embryos, and body structure.
•Branching Trees (phylogentic
Sometimes scientists change their hypothesis about species relationships.
• Giant Pandas and Lesser Pandas (red pandas): Lesser pandas
How Do New Species Form
•When a group of
individuals remains isolated from the rest of its species long enough to evolve
different traits.
•Separated by river, volcano, mountain range
•Isolated on an island
•Geographic Isolation: separation of populations within a species that results in 2 distinct species.
The Fossils Record: How Do Fossils Form
•Most fossils form when
organisms that die become buried in sediments.
•Petrified fossil: remains that are
buried in sediment change into rock.
•Molds: hollow space in
sediment in the shape of the an organism or part of an organism.
•Cast: copy of the shape of the
organism that made the mold.
•Preserved Remains: organisms
Determining a Fossil’s Age
•Relative Dating
•Used to determine
which fossil is older when rock layers have been preserved in
their original sequence.
•Does not tell a fossil’s
Determining a Fossil’s Age
•Radioactive Dating
•Determines actual age of fossils.
What Do Fossils Reveal
•Fossil Record: millions of
fossils that scientists have collected.
•Extinct Organisms
•Extinct: no members
of a species are still alive
•Almost all of the
What Do Fossils Reveal
•The Geologic Time Scale •Fossil record provided
clues about how and when new groups of organisms evolved
•Calendar of Earth’s history
is called the Geologic Time Scale
•Precambrium: largest
span of geologic time
Unanswered Questions
•Causes of Mass
extinctions?
•When many types of
Unanswered Questions
•There have been several
mass extinctions.
•Dinosaurs went extinct 65
mya during the Cretaceous.
•Major climate changes
may have cause the Cretaceous mass extinction.
•Created by an
asteroid that hit Earth.
•Dust clouds would
have blocked the
Rates of Evolution
•Gradualism:
evolution occurs slowly but steadily
•Punctuated