Download File

Diversity and
Evolution
SC.912.L.151
SC.912.L.15.10
SC.912.N.1.3
SC.912.N.2.1
SC.912.L.15.8
Darwin’s Theory of Evolution
by Natural Selection
Ideas that shaped Darwin
– Before Darwin, people believed Earth was 6,000 years old and
also relatively unchanged
1. Comte de Buffon
– Studied the fossil record
– showed that the Earth might be much older (4.3 and 4.5
billion years old)
2. James Hutton
– Layers of rock are moved by forces beneath Earth’s surface
– Most geological processes operate extremely slowly.
3. Charles Lyell
– geologic process that shaped the Earth in the past still
continue today
Ideas that shaped Darwin
Before Darwin people believed that species were
fixed….meaning plants and animals had always been the
way they are today
4. George Cuvier
• based fossils from different rock layers gave evidence
that organisms from the past differed greatly from
living species
5. Thomas Malthus
– suggested that if the human population continued to grow
unchecked, eventually there wouldn’t be enough food and living
space for everyone
– Famine, disease, and war
Ideas that shaped Darwin
6. Jean Baptiste de Lamarck’s
* 1809 published his theory of
evolution
* “More complex organisms
evolved from prior, less complex
organisms”
Larmarck
1. Use and Disuse
• Body parts develop with increased usage
• Unused body parts weaken
• CORRECT
2. Inheritance of Acquired characteristics
• Body parts acquired during lifetime of organism
can be passed on to offspring
• INCORRECT (only changes to genetic material in
gametes can be passed down)
3. Natural transformation of species
• Organisms produced offspring with changes,
transforming each subsequent generation into
a slightly different form, toward a higher order
of complexity
• Species never became extinct
• Species never split off into two new species
• INCORRECT
Evolution Assessment
• Pick up a piece of white paper from up front. You are creating a
POSTCARD that Charles Darwin is writing to Jean Baptiste Lamarck about
what his observed on his expedition to the Galapagos island.
– FRONT OF PAPER-
• TYPE Two WELL SUPPORTED paragraphs CREATIVELY describing what Darwin has
witnessed in the Galapagos Islands and his theories and ideas.
• Include and UNDERLINE vocabulary words and make sure to make your explanation
understandable to anyone
• FIRST PERSON (as Charles Darwin) to your friend Lamarck
• Address Lamrack’s views on evolution and explain how your evidence does not
support his findings
– BACK OF PAPER- Using your colored pencils, create a PICTURE(s) of what
Darwin observed on his expedition…remember, sometime postcards have a
few different pictures with one phrase on the front…be CREATIVE
• Your picture should support your paragraph on the back
100 point assessment AND project
Category
Maximum Points
Neatness
10
Creativity (overall postcard. Language,
presentation, etc)
20
Followed Directions
10
Relevant illustrations
10
Grammar, spelling, structure (complete
sentences)
10
Two paragraphs (5-7 sentences each)
20
Includes ALL Ideas of Darwin’s theory
8
Includes ALL Ideas of Lamarck’s theory
6
Colored
6
Voyage of the Beagle
• Darwin made a voyage around the word collecting
thousands of plant and animal specimens.
• His observations and collected evidence led him to
propose hypothesis that living things change over time
• Theory of Evolution through natural selection.
Voyage of
the Beagle
• Darwin noticed that plants
and animals on the
Galapagos islands of the
coast of Ecuador were
different from those on the
mainland and also from
island to island
Neck-size vs. Vegetation height
Galapagos’ Finches
Galapagos’ Finches
Darwin’s Theory
• 1859
• “On the Origin of Species”
•
proposed a mechanism for evolution called…
Natural Selection
NATURAL SELECTION
The ability of an organism to survive and
reproduce in its specific environment is
called fitness.
•
•
•
Individuals with characteristics that are not
well suited to their environment either die or
leave few offspring
Individuals that are better suited to their
environment survive and reproduce most
successfully.
Darwin called this process Survival of the
Fittest, or Natural Selection.
FITNESS
• describes how good a particular genotype is at
leaving offspring in the next generation relative
to how good other genotypes are at it
• Depends on ENVIRONMENT organism lives in
• A genotype's fitness includes:
• ability to survive
• Ability find a mate
• Ability to produce offspring — and ultimately leave its genes
in the next generation.
• if brown beetles consistently
leave more offspring than green
beetles because of their color,
brown beetles had a higher
fitness.
•
•
Fitness
Caring for your offspring and
producing thousands of young
(many of whom won't survive) and
sporting fancy feathers that attract
females are a burden to the health
and survival of the parent
• Strategies DO increase fitness
– help the parents get more of their
offspring into the next generation
Adaptations
• Superior inherited
traits to help an
organism survive
better in its
environment
• Adaptations increase
an individuals fitness
4 Principles of Natural Selection
•
•
•
•
Variation
Competition
Excess offspring
Survival of the Fittest
4 Main Principles of Natural
Selection
1. Variation exists within a
population
2. Organisms compete for
limited resources
3. Organisms produce more
offspring than can actually
survive
4. Individuals with variations
suitable for their habitat are
the ones that SURVIVE and
REPRODUCE
• Three species of lizard.
• B- The ones at the bottom live in the shrubland, and are colored to blend in.
•The top pictures show the
same species of lizard, but the
variety that lives in the White
Sands
•They all evolved to become
white (camouflage)
•The DNA on the bottom shows
the location of the mutation
that gives the white color
1. Inherited Variation
Individual organisms within the population differ. Most of this
variation is determined by genetic inheritance (recombination), but
sometimes it is the result of genetic mutations.
2. Struggle for Existence
Because so many offspring are produced, many will die due to a
lack of resources, predation, disease, or other unfavorable
conditions.
3. Overproduction of Offspring
Organisms produce more offspring than can survive.
Many of the offspring do not survive to reproductive age.
4. Differential Reproduction
Individuals best suited to their environment survive and reproduce
most successfully. Therefore these organisms pass their
advantageous traits to their offspring while offspring with
disadvantageous traits die or produce fewer offspring.
Descent with Modification
• Natural selection
causes species to
change over time.
• Species alive today
descended with
modification from
ancestral species.