Living
Non-Living?
Organize the following into your table..
•
•
•
•
•
Toenail
Sun
Hair
Nerve Cell
Leaf
•
•
•
•
•
Fire
Tree bark
Water
Algae
Bacteria
What makes
something alive?
Ideas?
7 Characteristics of Living
Organisms
1.
2.
3.
4.
5.
6.
7.
Feeding
Movement
Breathing/ Respiration
Excretion
Growth
Sensitivity
Reproduction
Biology song
• http://www.youtube.com/watch?v=aynclw6
TXeE
Where does it come from…?
The Big
Question:
????????
Can Living things
come from
Non-living things??
What is Spontaneous Generation?
• The idea that organisms originate directly from
non living matter
• “life from nonlife”
• ABIOGENESIS: the theory that states that non-living
things can be transformed into living things.
• abiogenesis
(a=not, bio= life, genesis= origin)
• It was common knowledge that simple
organisms could come from dust, mud and food
left out.
How Did This Happen?
Aristotle:
Greek
philosopher
(384-322
BC)
• Every year the Nile River flooded
leaving behind nutrient rich
soil that enables people to
grow that year’s crops.
• However, along with the muddy
soil, large numbers of frogs
appeared that weren’t around in
drier times.
How Did This Happen?
• Conclusion:
It was perfectly obvious to the people back
then that muddy soil gave rise to the frogs.
How Did This Happen?
• In many parts of Europe, medieval farmers
stored grain in barns with thatched roofs.
As a roof aged it started to leak. This could
lead to spoiled or moldy grain, and of
course, there were lots of mice around.
How Did This Happen?
• Conclusion:
It was obvious that the mice came from
the moldy grain.
van Helmont
• Even 300 years ago, a Belgian doctor, van
Helmont concluded that mice could be created
from grains of wheat and a dirty shirt.
• What was wrong with van Helmont’s
experiment?
Hello, Francesco Redi
• Italian Doctor most well-known for his
experiment in 1668 which is regarded
as a one of the first steps in refuting
spontaneous generation.
Up to this point, science was based on observation and
analysis…now, experiments were needed to test the
hypothesis…
In 1668, An Italian
physician,
Dr. Redi,
conducted an
experiment to
prove that flies
did not come
from rotting
meat. Very
controversial at
the time…
1. What was the experimental variable?
2. What was the controlled variable?
3. What was the “active ingredient” that
people believed was needed for
spontaneous generation?
The debate rages on…100 years later
• In 1748, John Needham performed an experiment
similar to Redi’s except that he wanted to study the
spontaneous generation of microorganisms instead of
maggots.
His experiment used 2 meat infusions which were both
boiled to kill the microorganisms , then one was left
open, the other was sealed with a cork. Micro-organisms
grew in both flasks. Needham saw it as proof of
spontaneous generation….
What do you think? What was the problem with this
experiment?
Lazzaro Spallanzani
Lazzaro Spallanzani was an Italian naturalist who
also attempted to disprove the Theory of
Spontaneous Generation, almost one hundred
years after Francesco Redi.
With the invention of microscopes after Redi's
death, scientists were able to see tiny organisms
that they could not see with the naked eye.
In the late 1700's, Lazzaro Spallanzani tried to
disprove this by performing a controlled experiment
with broth.
Spallanzani…trying to disprove Needham
Louis Pasteur
• Louis Pasteur was a French
chemist who finally disproved the
Theory of Spontaneous
Generation in the mid 1800's.
• Louis Pasteur performed the
same type of experiment as
Spallanzani, except both of his
flasks allowed air to enter
And so, 2000 years after it
started the debate of
abiogenesis vs. biogenesis is
settled:
Life comes from life, not from
spontaneous generation of nonliving things!!!
Biogenesis
• Biogenesis is the process of life forms
producing other life forms
LIVING
LIVING
LIVING
NON - LIVING
NON-LIVING
LIVING
(spontaneous generation doesn’t exist!!)
Passport: In Your Own Words
• What is the difference between
Abiogenesis and Biogenesis?
• Take a minute to write out the
contributions of each scientist and how
each affected the Abiogenesis vs.
Biogenesis debate.