Transcript Aim #75: How does evolution occur by natural

Date: April 19, 2016
Aim #75: How does evolution occur by natural selection?
Do Now: Warm-Up Notebook
Date
Title of Activity
4/19
Evolution Practice Questions
HW:
1)Darwin vs. Lamarck Article Review
2)Unit 7d due Friday, April 22nd
– Do not forget Castle Learning!!
Page #
116
Happy
Birthday
Cole!!!!
Aim #75: How does evolution
occur by natural selection?
1) How Does Evolution Occur?
• EVOLUTION is a slow change in a
species over time.
• Evolution occurs by a process called
NATURAL SELECTION.
Read this cartoon, what do you think NATURAL SELECTION is?
Lamarck’s theory of Evolution
Lamarck believed that by the selective USE or
DISUSE of characteristics, organisms lost or
acquired certain traits that would be passed
on to the offspring.
2) Charles Darwin
• Considered the “father” of evolution.
• Charles Darwin traveled to the Galapagos island, an uninhabited
environment, where he studied evolution (Darwin’s Finches)
3) Natural Selection
• NATURAL SELECTION is
the KEY to Darwin’s
theory.
• According to this theory,
evolution is controlled by
NATURE. Only the
organisms that are able to
SURVIVE and
REPRODUCE will pass on
their genes.
4) Natural Selection vs.
Artificial Selection
People select the desirable
traits that will appear in the
Offspring.
Environment selects
the desirable traits
that will appear in
the offspring.
5) Conditions that are vital to Evolution:
• Overproduction
• Variation
• Struggle For Survival
• Best Adapted To Survive
• Darwin did NOT have knowledge of the
genetic basis of inheritance
a) Overproduction
• More offspring are produced than can survive (most die
young).
Overproduction leads to
• Organisms suchCOMPETITION!!
as bacteria, fish, insects, and rabbits
have high reproductive rates because the chance that
their young will survive is minimal.
b) Variation
• Variation: Individuals have differences in their
appearance, structure, or genes.
• Source of variation:
+
=
– Sexual Reproduction (sperm + egg)
– Meiosis (Independent Assortment & Crossing Over)
– Mutation (Change in DNA)
• Mutations change the base
sequence of DNA.
• Many mutations are HARMFUL,
but some can help the organism
SURVIVE.
c) Best Adapted To Survive
• The ENVIRONMENT
chooses which traits
have adaptive value.
• An individual that has
traits favorable in a
certain environment will
live to reproduce and
pass on those traits,
others will die out.
Adaptive Value
• Adaptive Value: a change that produces a trait that
helps an organism survive.
-Example: Camouflage
• If all the members of a species were the same then an
environmental change would wipe out the entire
species. VARIATION increases the chance that some
members of a species will survive.
d) Struggle For Survival
• “Survival of the fittest”
• Only those BEST suited will survive because of
competition for finite (limited) resources (oxygen,
water, food, and shelter)
6) Conditions that lead to Evolution:
Activity:
• You are a naturalist who traveled to the
Galapagos Islands. The following are excerpts
from field notes. Choose a proper heading for
each of the notes
• Use these choices: overproduction, survival of
the fittest, competition, variation.
Overproduction
• Female finches found on the Galapagos Islands lay
enormous numbers of eggs
Competition
• These finches fight for a particular species of insect that
inhabits the small holes found in the tree bark
Survival of the fittest
• The finches with the long beaks survive and produce
greater numbers of offspring with long beaks
Variation
• Some finches’ beaks are long, some are
short. The finches with long beaks are
better adapted to remove the insects from
the bark.
Date: April 22, 2016
Aim #75: How does evolution occur by natural selection?
Do Now: Warm-Up Notebook
Date
Title of Activity
No Warm-Up Today 
HW:
1)Natural Selection Comic Worksheet
2)Unit 7e due Friday, May 13th
– Do not forget Castle Learning!!
Page #
Happy
Birthday
Tommy and
Michelle!!
3) Evolution Test Monday 5/9 and Tuesday 5/10
Date: May 2, 2016
Aim #75: How does evolution occur by natural selection?
Do Now: Warm-Up Notebook
Date
Title of Activity
Page #
HW:
1)Natural Selection Comic Worksheet
2)Unit 7e due Friday, May 13th
– Do not forget Castle Learning!!
3) Evolution Test Monday 5/9 and Tuesday 5/10
7) Patterns Of Change
Species with SHORT reproductive cycles that produce MANY
offspring tend to evolve more quickly than species with LONG life
spans and FEW offspring.
Types:
1) Gradualism – evolution occurs steadily through time (Slow &
Continuous) .
2) Punctuated Equilibrium- species stay the same for long
periods of time and then change rapidly.
Gradualism
Punctuated
Equilibrium
8) Examples of Natural Selection
• Industrial Melanism
• Antibiotic / Pesticide Resistance
Antibiotic Resistance
Ex: Punctuated Equlibrium
• When bacteria are exposed to an antibiotic there is a
chance that a few will have a gene that makes them
resistant.
• The bacteria WITHOUT the resistance will be killed, while
those that are RESISTANT will survive and pass on their
genes for antibiotic resistance.
The antibiotic is the selecting agent
Resistant
Bacteria
Antibiotic X
9) Why should we be concerned about antibiotic
overuse?
Why does evolution matter now?
http://www.pbs.org/wgbh/evolution/educators/teachstuds/svideos.html
https://www.youtube.com/watch?v=pc_Tx1h3qGc
Pesticide Resistance
Insect A- Has resistance to A
Insect B- Has resistance to B
Insect C- Has resistance to C
• What would happen to the
population if insecticide A were
sprayed on the field?
The pesticide selected
only those flies that
were resistant to
pesticide A to survive.
In other words, some
insects had a
MUTATION that
allowed them to
survive the presence of
the insecticide. These
insects were then able
to reproduce and pass
their mutation into the
next generation.
Extinction
• The disappearance of an entire species (ex. Dinosaurs)
• It can be caused by temperature changes, pollution, or
landscape changes.
Practice
Question
a. Identify one
concept being
represented in
the cartoon.
b. Briefly explain the
concept you
identified
Time Permitting
Supplemental Information
Examples of Organisms that are
Best Adapted to Survive
A cryptic frog - This species has developed a
coloring, texture and form that are similar to the
leaves found in its environment
Disruptive Coloration
• Stripes and spots
• Helps break up an
animal's outline
• Doesn't hide
animals presencemisrepresents it
Counter Shading-Top and Bottom
Desert
horned
lizard
on a
sandy
river bed
San Diego
Katydids
Plant or Animal?... Leafy Sea Dragon
• Chamaeleo pardalis,
a chameleon
species found in the
forests of
Madagascar
• Chameleons can
produce a wide
range of colors and
patterns on their
skin
A Von Höhnel’s chameleon turns
bark-like in Kenya.
•As the seasons change, the Arctic fox changes the
color of its coat.
•In the spring and summer, it has a dark coat, to
match the brown dirt in its environment.
•In the fall and winter, it turns white, to match the
surrounding snow.
Mimicry: monarch and
viceroy
Milk snake and coral snake
Aggressive Mimicry
• evolved devices with which
they mimic the prey (or
potential mate) of other
(usually smaller) predators.
• They use these devices as
lures
• The angler fish (Antennarius)
displays a lure resembling a
small fish
Warning Coloration: warns others that they may be
“unpleasant to eat” (poisonous)
Poison
Dart
Frogs