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AIM
What is
Evolution?
Evolutionary Theory
• Process of change
in species over a
long time
• They are
distinctly
different from
earlier forms
Proof of Evolution
• Fossils
provide clues
to the history
of earth’s
organisms
Proof of Evolution
• DNA Analysis
(Gel
Electrophoresis)
What did organisms evolve from?
Multi-cellular
Unicellular
How do organisms acquire new traits so
evolution can occur over many years?
• Crossing-over
during meiosis
when gametes
are formed
• Mutations in
gametes
(Sperm or egg)
Recombination in Gametes
• Crossover
(Sorting) during
meiosis
(Meiosis- special
cell division
when gametes
are formed)
Mutation in Gametes
• Base pair
sequence
change
• Change
passed on to
offspring
Leads to Variety
•Sexual Reproduction
(Crossover during meiosis)
•Mutations
Variation in Dogs
Variation in Ladybugs
Variation in Frogs
Variation in Finches
Passed to Offspring
• Mutations
passed to
offspring when
they occur in
gametes(sperm
or egg)
1.Which phrase best defines evolution?
1.an adaptation of an organism to its
environment
2.a sudden replacement of one community
by another
3.a geographic or reproductive isolation of
organisms
4.a process of change in organisms over a
period of time
2.Which two factors provide the genetic
basis for variation within a species?
1.asexual reproduction and geographic
isolation
2.mutations and sexual reproduction
3.competition and protein synthesis
4.constant gene frequency and
reproductive isolation
3.As a result of sexual reproduction,
an organism can pass a gene mutation
to its offspring if the mutation occurs in
1.a body cell
2.a gamete
3.liver tissue
4.white blood cells
Aim
How does evolution
occur?
Struggle for Existence
• Members of each
species compete
for food, living
space and the
necessities of life
• A finite supply of
resources
Fitness
• The member
that is better
fit will survive.
• Fitness-The
ability to
survive
Adaptation
• An inherited
characteristic
that increases
an organism’s
chance for
survival
Quills
Example-Adaptation
• Long tongue
lizard is better
adapted than a
lizard with a
short tongue.
Survival of the Fittest
• Individuals that
are better suited
to their
environment survive and
reproduce more
successfully
Natural Selection
• Survival of the
fittest is also
referred to as
Natural Selection
• Environment
changes first,
those best
adapted survive
Adaptations
• Beneficial traits
will be passed on
to offspring
(More frequency)
• Unfavorable
traits will be less
common
Favorable Traits
• Those best adapted
pass on favorable
adaptations to their
offspring
• Higher frequency of
favorable traits are
passed along to
offspring increasing
chances for survival of
the species
Camouflage
1.In most populations, the
individuals that produce the
greatest number of offspring are
1.always the strongest
2.usually the best adapted
3.those that have only recessive
traits
4.those that are the most intelligent
2.According to modern evolutionary theory,
genes responsible for new traits that help a
species survive in a particular environment
will usually
1.not change in frequency
2.decrease gradually in frequency
3.decrease rapidly in frequency
4.increase in frequency
3.Even though the environment changes, a
population that occupies a given geographic area
will most likely continue to be found in this area
if the
1.variations in the population decrease over time
2.members of the population decrease in
number
3.members of the population exceed the carrying
capacity
4.population passes on those genes that result in
favorable adaptations
Aim
What conditions are
important to evolution?
Force behind Evolution
• The interaction
between
individual
organisms and
the environment
Conditions Important to Evolution
Variation
(Differences)
• Overproduction
• Finite supply of
resources (limited)
• Natural Selection
•
Variation
• New traits that
can lead to
evolution come
from normal
variation within
species
Overproduction
• Population of a
species remains
stable
• Turtle eggs
Struggle for Survival
• Finite Resources
(not enough)
• Competition among
individuals of a
species mean only
the most adapted to
the environment will
survive
Natural Selection
• Evolution is
controlled by
nature not people
• Organism that are
best adapted to an
environment will
survive
Selection by Environment
• The proportion of
individuals with
advantageous
traits will increase
• This change over
time is evolution
AIM
What are the changes
organisms undergo from
Genetic Variation?
Sources of Variation
• Sexual
Reproduction
(Crossover
during Meiosis)
• Mutations
Results of Variation
1.Structural
Change
2.Functional
Change
3.Behavioral
Change
Structural Change
• Homologous
structures Have different
mature forms but
developed from the
same ancestors
(embryonic tissues)
The bones in the forelimbs of three mammals are shown
below.
For these mammals, the number, position, and shape of the
bones most likely indicates that they may have
1.developed in a common environment
2.developed from the same earlier species
3.identical genetic makeup
4.identical methods of obtaining food
Functional Change
• HumansElectrical
Impulses to
move muscles
• Eels -Electrical
impulses to
shock and kill
its prey
Behavioral Change
• Rate of light
blinking helps
organisms
recognize
same species
for mating
Some behaviors such as mating and caring
for young are genetically determined in
certain species of birds. The presence of these
behaviors is most likely due to the fact that
1.birds do not have the ability to learn
2.individual birds need to learn to survive and
reproduce
3.these behaviors helped birds to survive in the
past
4.within their lifetimes, birds developed these
behaviors
Evidence of Common Ancestors
• If Amino acid
sequence in
proteins they
synthesize are
similar
• Suggests DNA is
also similar
(Controls Synthesis)
Things to Remember
• Individuals that
produce the most
offspring are the
best adapted to
the environment
The kit fox and red fox species are closely related. The kit fox lives in the desert, while
the red fox inhabits forests. Ear size and fur color are two differences that can be
observed between the species. An illustration of these two species is shown below.
Which statement best explains how the differences between these two species came
about?
1.Different adaptations developed because the kit fox preferred hotter environments
than the red fox.
2.As the foxes adapted to different environments, differences in appearance evolved.
3.The foxes evolved differently to prevent overpopulation of the forest habitat.
4.The foxes evolved differently because their ancestors were trying to avoid
competition.
Aim
What affects the rate
of evolution among
organism?
Affects Rate of Evolution
• Environmental
Change
- More Environmental
change equals more
Evolution
- Less Environmental
change equals less
Evolution
Horseshoe crab
Affects Rate of Evolution
• Offspring
Produced
- The more you
produce the
quicker organism
evolves over time
Affects Rate of Evolution
• Time of Lifespan
Lifespan for
bacteria and
insects are short
so they evolve
quicker compared
to humans
• More life cycles
Affect on Bacteria
• Increase in
evolutionary rate
causes more
mutations and
produces
antibiotic resistant bacteria
Antibiotic Resistant Bacteria
• Caused by a
Mutated
Bacteria
• The Doctor has
to change the
antibiotic to kill
mutated form
Common Names
Names of Bacteria
Names of Antibiotic
• Streptococcus
• Staphylococcus
• S. Aureus
• Meningitis
• Penicillin
• Erythromycin
• Tetracyline
• Keflex
Summary
Red bacteria is
mutated
• Antibiotic kills
normal
bacteria(blue)
• Mutated bacteria is
resistant to antibiotic
and multiplies (Red)
• Doctor has to change
to another antibiotic
that can kill resistant
bacteria
AIM
What patterns does
evolution follow which
are supported by fossil
records?
#1-Pattern of Change
• Changes in
species is often
related to
environmental
change
#2 Pattern of Change
• Species with quicker
reproductive cycles
and shorter life
spans will
evolve quicker
Examples- Bacteria,
insects and
mosquitoes
#3-Pattern of Change
• The failure to
adapt to a
changing
environment may
result in death of
the species.
This is called
extinction
Things to Remember
• Species with very little
variation face possible
extinction if the
environment changes
• More variation; better
chance to survive a
changing environment
• Organisms with the
quicker reproductive
cycles evolve faster
Evolution Diagram
• Species that don’t
reach the top are
extinct.
• Species that are
similar split from
the same lines.
• Which to species
are extinct?
J and E
The diagram shows an interpretation of relationships based on
evolutionary theory. The letters represent different species.
Which species are least likely to be vital parts of a present-day
ecosystem?
1.species A and E
2.species C and D
3.species E and J
4.species B and F
The diagram shows an interpretation of relationships based
on evolutionary theory. The letters represent different species.
Which species are least likely to be vital parts of a present-day
ecosystem?
1.species A and E
2.species C and D
3.species E and J
4. species B and F
Aim
How did Charles Darwin’s
study of finches lead to
modern evolutionary
theory?
Why do these Finches have different
beak sizes?
Charles Darwin
• Darwin was
the father of
modern
evolution
Studied Finches
• Darwin studied
finches on the
Galapagos islands
off the coast of
South America
• Environments
were different
Finches are Birds
The Finches’ Beaks
• Beaks of each
finch were
different
• Natural selection
determined the
shape and size
of each beak
Environmental Factors
Which beak the
bird developed
depended on the
finches niche.
• Niche- what an
organism eats
(seeds)
•
Common Ancestor
• All the Finches
descended from
A common
ancestor
1.Darwin’s studies of finches on the Galapagos
Islands suggest that the finches’ differences in
beak structure were most directly due to
1.acquired characteristics in the parent finches
2.the size of the island where the finches live
3.mating behaviors of the different finch species
4.adaptations of the finches to different
environments
According to Darwin’s theory of
evolution, differences between
species may be the result of
1.the disuse of body structures
2.the transmission of acquired
characteristics
3.natural selection
4.mutagenic agents
Class Activity: Animal Cell
Organelle
Cell Membrane
Nucleus
Cytoplasm
Vacuole
Ribosome
Mitochondria
Number
Function
Substance
Aim
Review of Evolution
Definition of Evolution
• The change
of a species
over a long
time
Proof of Evolution
•Fossils
•DNA
Analysis
Electrophoresis
• Process used to
analyze DNA in
Fossils and
match to DNA in
current species
• Band position
matches
Genetic Variety for Evolution
• Sexual
Reproduction
• Mutations
• Crossover during
Meiosis-gamete
formation
Conditions Important to Evolution
Variation
(Differences)
• Overproduction
• Finite supply of
resources (limited)
• Natural Selection
•
Changes from Evolution
1.Structural
Change
2.Functional
Change
3.Behavioral
Change
Structural Change
• Homologous
structures Have different
mature forms but
developed from the
same ancestors
(embryonic tissues)
Adaptation
• An inherited
characteristic
that increases
an organism’s
chance for
survival
Patterns of Change
• Changes in species are
related to
environmental change
• Short reproductive
cycles and many
offspring leads to more
change
• Failure to adapt leads to
extinction
Facts on Charles Darwin
• Studied the
Finches on
Galapagos islands
• Finches developed
different beaks
based on their
habitats
(environments)