Transcript Evolution - Cinnaminson School

1. Cut and glue a picture of something alive
onto the paper.
2. Identify its name and kingdom.
3. Identify the following: uni or multicellular,
pro or eukarytotic
4. Describe its phenotype (think internally
too- does it have a brain, digestive
system, blood, exoskeleton or internal
skeleton, does it belong to a groupinsects, fish, reptiles, birds, mammals?)
Evolution
Changes in inherited
characteristics over time.
1. Look at the picture of the living organism.
2. It has been labeled with its name and
kingdom.
3. It has been identified as unicellular or
multicellular, prokaryotic or eukaryotic.
4. Its phenotype has been described,
including internal structures and any
group it is part of.
5. Look at your organisms, what things do
they have in common? Are some more
similar than others?
6. How would you group them?
Ideas about Evolution to discuss
• Look at the statement your group was
given.
• Can you help explain it and give examples
to the rest of the class?
• Write down your ideas, we will share them
in a few minutes.
Ideas about Evolution to discuss
• In the game of evolution, you don’t have to
be the best, you just have to be better than
your competitors.
Ideas about Evolution to discuss
• Is evolution about climbing a ladder toward
perfection?
Ideas about Evolution to discuss
• Many species are similar to one another.
Ideas about Evolution to discuss
• Do more genes and chromosomes make
you “better”?
Ideas about Evolution to discuss
• Are humans an example of “the perfect
species”?
Ideas about Evolution to discuss
• Our closest living
relative is the
chimpanzee.
Ideas about Evolution to discuss
Ideas about Evolution to discuss
• In the game of evolution, you don’t have to
be the best, you just have to be better than
your competitors.
Ideas about Evolution to discuss
• Is evolution about climbing a ladder toward
perfection?
Blind Cave Fish
Ideas about Evolution to discuss
• Many species are similar to one another.
• Species as diverse as plants, bacteria,
and humans share about 500 of the same
genes.
Ideas about Evolution to discuss
• Do more genes and chromosomes make
you “better”?
• A salamander’s DNA genome is about 25
times longer than ours. Some amoebas
have hundreds of chromosomes, humans
have only 46.
Ideas about Evolution to discuss
• Are humans an example of “the perfect
species”?
• Humans are less complex than other
organisms in many ways.
Ideas about Evolution to discuss
• Our closest living
relative is the
chimpanzee
• But, we did NOT
evolve from it,
rather we both
evolved from a
common ancestor.
Ideas about Evolution to discuss
http://www.youtube.com/wat
ch?v=zGqae7vuUWo&feature=
PlayList&p=60D07D9950E069
A4&playnext_from=PL&playne
xt=1&index=16
Evolution
• Change in inherited characteristics over
time. (Descent with modification)
Before the 1800’s few thought
much about evolution
1. Most people thought the earth was only
6,000 years old (not 4.6 billion years old)
2. Few traveled to see similarities in species
3. Many people (of European descent)
understood only the biblical story of
creation.
http://mythicjourneys.org/bigmyth/
In the 1800’s scientists started to
change people’s minds….
Lamarck
• A French scientist who proposed that traits
developed during a parent’s life would be
passed onto their kids.
Example: giraffes
stretch their neck
to reach tall leaves,
this results in a
long neck. This
trait is then
inherited by the
kids.
Lamarck didn’t realize not all things
are passed onto the offspring
=
Plastic Surgery does NOT get
passed onto your offspring!
Before surgery
After surgery
Genetics wasn’t described until the
1860’s by Mendel
Charles Darwin
• A British scientist who studied nature and
noticed similarities among animals.
• He concluded
that living things
must be related
and somehow
they changed, or
evolved, over
time due to
natural selection.
Natural Selection
• An organism with the best traits for their
environment is more likely to survive and
reproduce
Which mouse
is better suited
for this
environment?
Survival of the Fittest
• Which moth has
the best traits for
this
environment?
• What will
happen to the
“unfit” moth?
Today and Tomorrow
• Today: Complete the natural selection
scenarios worksheet.
• Tomorrow: You will be playing the role of a
bird and you will “inherit” a type of beak.
You will compete against other beaks to
see which is the best trait for the
environment and which one will “win” and
survive.
Each beak shape influences food
choice
Which beak will each type of food?
Natural Selection
• An organism with the best traits for their
environment is more likely to survive and
reproduce
• Scenario 1: A garden. Two different
types of flowers grow here, one is a red
rose with thorny stems and one is a red
rose with smooth stems. A rabbit moves
into the garden and wants to eat flowers.
Which flower will survive?
• How is this an example of natural
selection?
• Scenario 2: A tree. Two different species
of bugs live on the tree. A stick bug, which
resembles a dead twig and a fuzzy
caterpillar. A bird moves into the area and
wants to eat bugs. Which bug will survive?
• How is this an example of natural
selection?
• Scenario 3: A hot desert. Two different
lizards are dropped here. One lizard (A) is
diurnal, or active during the daytime. One
lizard (B) is nocturnal, or active during the
nighttime. Hawks which eat lizards are
diurnal. Which lizard will survive
• How is this an example of natural
selection?
• Scenario 4: A high
school. Two different
students transfer into the
school halfway through
the year. One student, a
boy, is well behaved,
talented in chorus, and is
nice to others. The
second student, a girl, is
unkind and does not talk
to other students. Which
student has a better
chance at finding a date
for the senior prom?
• Explain how this is an
example of natural
selection.
How does beak shape affect
survival?
Bird Beak Adaptations
• Beaks: Spoon, tongs, tweezers, scissors
• Food: Toothpicks, string, beans, pennies
Conclusion
1. The ______ beak was best adapted to
eat _____ because______. (tongs,
tweezers, scissors, best overall)
2. Was your hypothesis supported?
3. How does the shape of a bird’s beak
affect how it survives?
How Natural Selection Works
• How does the “fittest” organism happen?
How do we get organisms with the
best traits?
1. Lots of offspring
2. Differences or variations occur in those
offspring (due to sexual reproduction or
mutations)
3. Some variations are helpful, this results
in a better chance of survival,
reproduction, and passing on of those
good variations.
4. Over time, individuals with new variations
may become a new species. This is
evolution.
Giraffes with long necks exist
because…
1.
2.
3.
4.
Mom and Dad giraffe had lots of
offspring
Those offspring were each
different.
Some had helpful variations
(longer necks) which meant
better survival (more food) and
more likely to reproduce.
Long neck genes get passed on
to future offspring, eventually a
new species of giraffe occurs.
•
•
•
•
Mom and Dad bug had
lots of offspring
Those offspring were
each different.
Some had helpful
variations (grey) which
meant better survival
(not eaten) and more
likely to reproduce.
Grey genes get
passed on to future
offspring, eventually a
new species of bug
occurs.
http://www.nysci.org/explore/ontour/charlieandkiwi/Charlie
s-and-Kiwis-Evolutionary-Adventure-Video
Adaptations are variations that
make an organism better suited for
its environment.
• Adaptations can be physical (on their
body) or behavioral.
Adaptations can help an
organism….
Attract a mate
Warn predators
Hide from predators (camouflage)
http://www.youtube.com/watch?v=k8RlGbpuhgc
Imitate a more
dangerous
animal (mimicry)
mimicry
Geographic
Isolation can allow
some variations to
appear in a
species that might
have been
otherwise stayed
hidden
Geographic Isolation
Geographically Isolated Animal
Examples
Flightless birds and mouse lemurs
Speed of Evolution
• Gradualism- a continuous series of
mutations and variations over time will
result in a new species.
• Punctuated Equilibrium- rapid evolution
that occurs when the mutation of a few
genes results in the appearance of a new
species over a relatively short time.
+
The 0.1% of bacteria
that survives,
reproduces and now is
resistant to the spray
http://www.youtube.com/watch?v=BwuL4J_jEyc&feature=related
How many germs will survive?
20,000 single celled organisms, which are
genetically different from the dead, will still
survive and continue to reproduce.
So what? Why does
evolution matter?
http://www.youtube.com/watch?v=6jBD8xfbf4Y
The End of Evolution….or is it?
http://www.youtube.com/watch?v=z
Gqae7vuUWo&feature=PlayList&p=60
D07D9950E069A4&playnext_from=PL
&playnext=1&index=16