The Evolution of Spontaneous Generation: A Scientific Journey
Spontaneous Generation
•
Before the 17
th
century the belief of where life came
from was
Spontaneous Generation:
•
Living things come from non-living things
•
Ex. Throwing waste into the street creates rats and flies
•
3 scientists tested this hypothesis:
•
Redi
•
Spallanzani
•
Pasteur
“Slow Death of Spontaneous Generation”
On the back of the article, there is a chart to show how the three
scientists experimented with Spontaneous Generation.
Copy the chart in your science notebook and fill in the chart (in your
notebook) as you read the article.
Tuesday 1/27/2015
Agenda
: Evolution
Notes: Spontaneous Generation
Notes: Biogenesis
Activity: Human Hand Adaptation
GRADE CHECKS TODAY! (1
st
Hour Only)
Homework/Class Work:
No Homework Tonight!
Maggots
developed from
eggs of flies
2 jars with
meat: one
covered with
cheese cloth &
other open
The
uncovered jar
had maggots
& the covered
one didn’t
Spontaneous
generation
does
not
occur
Spontaneous
generation
does
not
occur.
Microorganisms
are produced by
other
microorgansisms
Boiled chicken
broth in flask &
curved neck
into sideways
“S” shape.
No
microorganisms
grew
Spontaneous
generation
does not
occur.
Microorganisms
are produced by
other
microorgansisms
Sealed flask of
chicken broth
took out air &
boiled it
No
microorganisms
grew
Spontaneous Generation: Venn diagram
Redi’s Experiment
•
4 jars of meat
•
Two open jars vs. two closed jars
•
Result: Maggots and flies were only found in the
open jars
What do
these results
tell us?
Spallanzani’s Experiment
•
Boiled meat broth in 2 flasks
•
Open
flask
vs
.
sealed
flask
•
Result: After three days,
the
broth in the open
flask was cloudy = microorganism growth
What do
these results
tell us?
Pasteur’s Experiment
•
He
redid Spallanzani’s experiment
•
Used a curved neck flask
•
Left it open for one year
•
Result: remained clear
•
Broke the neck
•
Left it for one day (it was cloudy)
What do
these results
tell us?
•
Conclusion to all 3 experiments:
spontaneous generation
has been
disproved!
•
The
New hypothesis:
Biogenesis:
all living things come
from other living things.
Species & populations!
•
SPECIES
:
•
A group that is reproductively isolated (
organisms that can
breed & produce fertile offspring
)
QUESTION:
Can two
different
species mate
& produce an
offspring?
THIS IS A LIGER
THIS IS A MULE
The Liger…
•
Male lion and
female tiger
•
Like most hybrids
they are sterile
•
However an
occasional female
has been found
which can
reproduce. No
fertile males have
been found.
POPULATION:
a
group of individuals of the same species
that are
not
prevented from breeding & producing offspring
.
QUESTION:
Name one circumstance in which 2
groups of a single species of
squirrel might be prevented from
breeding with each other.
ANSWER:
The groups may have gotten separated
geographically and are unable to
interact or breed.
•
ADAPTATION:
•
is any
inherited characteristic that increases
an organism’s chance of surviving
in a
particular environment.
•
FITNESS:
•
an
organism’s ability to survive
in order to
reproduce
in an environment.
Human Hand Adaptation
•
Each
PAIR
should have a bucket & a yellow
handout
What is NOT included:
•
Masking tape
•
Pencil
•
Book
•
Shoe
•
Backpack with zipper
Wednesday/Thursday 1/28-1/29/2015
Agenda
: Evolution
Activity: Finish Human Hand Adaptation
Notes: Adaptations
Activity: Zygoozles
Homework/Class Work:
No Homework Tonight!
TYPES OF ADAPTATIONS
1. Structural
2. Behavioral
3. Physiological
Let’s look at each type as we consider 2 species:
the tundra & icecap-dwelling arctic fox & the
desert dwelling fennec fox.
arctic fox (
Alopex lagopus)
fennec fox (
Vulpes zerda)
Structural Adaptation
: The form that the
organism takes.
EX: Big ears and small ears of foxes.
Heat escapes easily from the blood that passes through the
vessels in the fennec fox’s ears. Cool blood from the ears then
circulates through the body & keeps the fennec fox from
overheating.
Behavioral Adaptation:
These are innate or
inherited actions that individuals of the species
perform.
•
Arctic fox:
•
Can be active any time of the day; ready to find food
whenever available.
•
Fennec fox:
•
Is nocturnal; sleeps during the day & hunts at night
Physiological Adaptation
:
Related to the
biochemical processes at work within an
organism’s body.
•
Compare the processing of food & water:
•
Arctic fox: food is scarce in winter; effective at storing food
energy as fat.
•
Fennec fox: little free water available; adapted to get all
moisture it needs from fruit, roots, & leaves.
Adaptations Work Together
•
Adaptations work together to
produce a species fit for surviving
in a specific environment.
The big ears(
structural
)
cools fox & gives acute
hearing which helps when
fox hunts & night
(
behavioral
) & the fox has
special retina; tapetum (
physiological
)
that gives the fox night vision.
PROCEDURES
1. You will examine the zygoozles. Discuss the
similar & different traits the organisms possess.
2.Cut out each organism. Decide which organism
represents the
ancestral form
(you get to pick).
3.Arrange the organisms in the order you believe
they evolved.
4. Once you have decided where the pictures will
be, glue the pictures in place on the paper.
5. Draw an arrow between each picture
and state the change
to show the direction of evolutionary change.
6. Choose 5 arrows and
write a statement by each picture to
justify
the change that occurred.
7. Draw a picture of the fossil that could evolve next.
Explain why the creature would have the traits you gave it.
Describe a structural, behavioral and physiological
adaptation
8. Color and decorate your paper to make it appealing.
PROCEDURES
Explore the historical progression of the Spontaneous Generation theory through the experiments and discoveries of scientists like Redi, Spallanzani, and Pasteur. Witness the shift from the belief that living things can arise from non-living matter to the establishment of biogenesis principles. Follow along as each experiment refutes the notion of spontaneous generation, paving the way for a deeper understanding of life's origins.
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Presentation Transcript
Our Story in 2 minutes http://www.youtube.com/watch?v=MrqqD_Tsy4Q
Spontaneous Generation Before the 17thcentury the belief of where life came from was Spontaneous Generation: Living things come from non-living things Ex. Throwing waste into the street creates rats and flies 3 scientists tested this hypothesis: Redi Spallanzani Pasteur
Slow Death of Spontaneous Generation On the back of the article, there is a chart to show how the three scientists experimented with Spontaneous Generation. Copy the chart in your science notebook and fill in the chart (in your notebook) as you read the article.
Tuesday 1/27/2015 Evolution Evolution Agenda: Evolution Notes: Spontaneous Generation Notes: Biogenesis Activity: Human Hand Adaptation GRADE CHECKS TODAY! (1st Hour Only) Homework/Class Work: No Homework Tonight!
Scientists Hypothesis Draw the Experiment 2 jars with meat: one covered with cheese cloth & other open Results Conclusion The uncovered jar had maggots & the covered one didn t Redi Maggots developed from eggs of flies Spontaneous generation does not occur Boiling liquid will kill microorganisms Boiled broth into a flask, sealed & waited Microorganism s grew in the flask Spontaneous generation DOES occur Needham Microorganisms are produced by other microorgansisms Sealed flask of chicken broth took out air & boiled it Spallazani No Spontaneous generation does not occur. microorganisms grew Pasteur Boiled chicken broth in flask & curved neck into sideways S shape. Microorganisms are produced by other microorgansisms No Spontaneous generation does not occur. microorganisms grew
Redis Experiment 4 jars of meat Two open jars vs. two closed jars Result: Maggots and flies were only found in the open jars What do these results tell us?
Spallanzanis Experiment Boiled meat broth in 2 flasks Open flask vs. sealed flask Result: After three days, the broth in the open flask was cloudy = microorganism growth What do these results tell us?
Pasteurs Experiment He redid Spallanzani s experiment Used a curved neck flask Left it open for one year Result: remained clear Broke the neck Left it for one day (it was cloudy) What do these results tell us?
Conclusion to all 3 experiments: spontaneous generation has been disproved! The New hypothesis: Biogenesis: all living things come from other living things.
How are organisms broken up?? Species & populations!
SPECIES: A group that is reproductively isolated (organisms that can breed & produce fertile offspring) QUESTION: Can two different species mate & produce an offspring?
THIS IS A LIGER THIS IS A MULE
The Liger Male lion and female tiger Like most hybrids they are sterile However an occasional female has been found which can reproduce. No fertile males have been found.
POPULATION: a group of individuals of the same species that are not prevented from breeding & producing offspring. QUESTION: QUESTION: Name one circumstance in which 2 groups of a single species of squirrel might be prevented from breeding with each other. ANSWER: ANSWER: The groups may have gotten separated geographically and are unable to interact or breed.
ADAPTATION: is any inherited characteristic that increases an organism s chance of surviving in a particular environment. FITNESS: an organism s ability to survive in order to reproduce in an environment.
Human Hand Adaptation Each PAIR should have a bucket & a yellow handout What is NOT included: Masking tape Pencil Book Shoe Backpack with zipper
Wednesday/Thursday 1/28-1/29/2015 Evolution Evolution Agenda: Evolution Activity: Finish Human Hand Adaptation Notes: Adaptations Activity: Zygoozles Homework/Class Work: No Homework Tonight!
TYPES OF ADAPTATIONS 1. Structural 2. Behavioral 3. Physiological Let s look at each type as we consider 2 species: the tundra & icecap-dwelling arctic fox & the desert dwelling fennec fox.
arctic fox (Alopex lagopus) fennec fox (Vulpes zerda) Structural Adaptation: The form that the organism takes. EX: Big ears and small ears of foxes. Heat escapes easily from the blood that passes through the vessels in the fennec fox s ears. Cool blood from the ears then circulates through the body & keeps the fennec fox from overheating.
Behavioral Adaptation: These are innate or inherited actions that individuals of the species perform. Arctic fox: Can be active any time of the day; ready to find food whenever available. Fennec fox: Is nocturnal; sleeps during the day & hunts at night
Physiological Adaptation: Related to the biochemical processes at work within an organism s body. Compare the processing of food & water: Arctic fox: food is scarce in winter; effective at storing food energy as fat. Fennec fox: little free water available; adapted to get all moisture it needs from fruit, roots, & leaves.
Adaptations Work Together Adaptations work together to produce a species fit for surviving in a specific environment. The big ears(structural) cools fox & gives acute hearing which helps when fox hunts & night (behavioral) & the fox has special retina; tapetum (physiological) that gives the fox night vision.
PROCEDURES 1. You will examine the zygoozles. Discuss the similar & different traits the organisms possess. 2.Cut out each organism. Decide which organism represents the ancestral form (you get to pick). 3.Arrange the organisms in the order you believe they evolved. 4. Once you have decided where the pictures will be, glue the pictures in place on the paper.
PROCEDURES 5. Draw an arrow between each picture and state the change to show the direction of evolutionary change. 6. Choose 5 arrows and write a statement by each picture to justify the change that occurred. 7. Draw a picture of the fossil that could evolve next. Explain why the creature would have the traits you gave it. Describe a structural, behavioral and physiological adaptation 8. Color and decorate your paper to make it appealing.
