Download Natural Selection and the Evidence of Evolution

Natural Selection and the Evidence
of Evolution (15.1)
Evolution Foldable
1. Fold 4 pieces of paper, so you have 7
layered flaps
2. Write “Evolution” on the top flap as a
title
On each flap write:
1.
2.
3.
4.
5.
6.
7.
Modern Theory of Evolution
Origins of Evolution
Natural Selection & Types
Influences of Evolution
Patterns of Evolution & Speciation
Evidences of Evolution
Evidences continued…
1. Modern Theory of Evolution
(Inside) On Top Half of 1st Flap draw:
What is Evolution?
What is Natural Selection?
EVOLUTION
Why makes certain individuals
more able to survive?
How does Natural
Selection work?
What is evolution?
The change in populations over time.
Insights into why only
certain individuals survive…
• Traits vary among populations; these traits
are inherited
• Breeding with others that had desirable
traits produced offspring with these traits
What is natural selection?
• Mechanism of change in populations over
time
(Inside) On Bottom Half of 1st Flap:
Who is Darwin?
Who is Malthus?
Who is Charles Darwin?
• English scientist/naturalist
whose ideas provide
foundation for the theory of
evolution by natural selection
• Sailed on HMS Beagle for 5
years studying and collecting
biological and fossil
specimens
Major Ports of Call…
• Galapagos Islands
– Location: Near equator, 1000km off west
coast of S. America
– What he studied: many species of animals
and plants unique to the island, but are similar
elsewhere
– Major findings: Observations led to his
consideration that species change over time
Darwin’s book…
• 1859, The Origin of
Species
• Detailed account on
his ideas and
theories that
support evolution
Darwin’s Hypothesis…
• Artificial Selection- breeding organism with
specific traits in order to produce offspring
with identical traits
• There is force in nature that works like
artificial selection
Thomas Malthus
• Proposed idea that human populations
grow faster than Earth’s food supply
How Malthus affected Darwin’s
ideas…
• Realized organisms struggle to compete in
changing environments. Many types of
competition exist:
– Food and space
– Escaping predators
– Location of shelter
2. Origins of Evolution
(Inside) On Top Half of 2nd Flap draw:
BIOGENSIS
SPONTANEOUS
GENERATION
Spontaneous Generation
• Theory states that non-living matter
produces life
• Disproved by Redi’s Experiment
“Life does not just appear, it comes from other
living things”
Biogenesis
• Theory that living things come from other
living things
• Proven by Pasteur’s experiment
(Inside) On Bottom Half of 2nd Flap :
• Paste/Tape pictures
3. Natural Selection
(Inside) On Top Half of 3rd Flap draw:
What is Natural Selection?
How does it occur?
NATURAL SELECTION
What are the types of Natural
Selection?
Picture
Natural Selection
What is it?
• Change in an allele
over a period of time
How does it occur?
• Occurs in
populations! Evolution
can not occur in a
single individual
Types of Natural
Selection are:
• Stabilizing
• Directional
• Disruptive
Picture:
(Inside) On Bottom Half of 3rd Flap write:
Glue in the following picture & Label the following:
A) mode of natural selection in
which a single phenotype is
favored, causing the allele
frequency to continuously shift
in one direction
B) Mode of natural selection in
which genetic diversity
decreases as the population
stabilizes, selects against
extreme values of the
character and favors the
intermediate variants
C) extreme values for a trait are
favored; the variance of the
trait increases and the
population is divided into two
distinct groups
4. Influences of Evolution
(Inside) On Top Half of 4th Flap write:
Glue in the following picture & Label the following:
Genetic Equilibrium
• Defined as the frequency
of alleles that remains the
same over generations
• Evolution only occurs
when alleles are not in
equilibrium
• Label the picture that
shows “genetic
equilibrium”
Mutations
• Any change in DNA
• Causing individuals in a
population to express a
new phenotype
(Inside) On Bottom Half of 4th Flap write:
Glue in the following picture & Label the following:
Gene Flow
• also called migration
• addition of genes into
a population
• alters allelic
frequencies
Genetic Drift
• random events
remove genes from a
population
• gene frequencies in a
population change
5. Patterns of Evolution &
Speciation
(Inside) On Top Half of 5th Flap write:
Glue in the following picture & Label the following:
Divergent Evolution
Convergent Evolution
• Species that evolve to be
different even though
they come from a
common ancestor
• Species that evolve to be
similar to each other
• For example: they have
similar structures
(Inside) On Bottom Half of 5th Flap write:
Glue in the following picture & Label the following:
Speciation
• a lineage-splitting
event that produces
two or more separate
species
6. Evidences of Evolution
(Inside) On Top Half of 6th Flap write:
Evidences of Evolution
• Adaptations- structural and physiological
• Fossil Evidence
• Comparative anatomy
– Homologous, analogous, vestigial
• Embryology
• Geographical distribution of species
– biogeography
• Biochemistry
– DNA analysis
in a species over many generations
Continuation
Why?
– Variation that aids an organisms chances of survival
in its environment
– Develop
(Inside) On Bottom Half of 6th Flap write:
Structural Adaptations
Physiological Adaptations
• What are they?
– Changes in
– Protect against predators
organism’s
• Mimicry
metabolic processes
– Enables one species to • Example:
resemble another
– After years of
exposure to specific
• Camouflage
pesticides, insects
– Enables species to blend
and weeds have
with surroundings
become resistant
• Teeth and Claws
(Inside) On Top Half of 7th Flap write:
Fossil Evidence
• Indirect source
• Provide record of early
life
• As record becomes more
complete, the sequence
of evolution is clearer
Anatomical Evidence
1.
Homologous Structurescommon evolutionary origin
2. Analogous Structures- no
common origin, but similar in
function
(Inside) On Bottom Half of 7th Flap write:
Anatomical Evidence
•
Vestigial- body structure in
present day organism that no
longer serves original purpose
Embryological Evidence
• Similarities in development
before birth
Biochemical Evidence
• All organisms share DNA, ATP
and many enzymes among
their biochemical molecules