Natural Sciences II
Lecture #1
June 23, 2009
Josephine S. Bautista-Guerrero, MD
PhD Biology (c)
What is a “Fact” and
What is a “Theory”?
Excerpt from: Scott, Eugenie C. 1996. Dealing with
Antievolutionism. In Learning from the Fossil Record.
A Fact
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Is a confirmed observation
Implies TRUTH
May change
Is accepted and can be used as a given to
build more complex understanding
Examples of FACTS
• Every tetrapod has
– A humerus
– A radius and ulna
– Carpals, metacarpals and phalanges
Examples of FACTS
• Homo sapiens was thought to have 48
chromosomes
A Theory
• Is a logical construct of facts and
hypotheses that attempt to explain a
natural phenomenon
• Is an EXPLANATION
• (Theory formation) Is the goal of science
What is Natural Science?
Natural Science
• Pertains to nature
• Earth and Life Sciences
– vs. Physical sciences
– vs. Social sciences
– vs. Formal sciences (a priori)
Natural Science
• Naturalistic approach to studying the universe
“The doctrine that nature is all there is....
... Is based on naturalism”.
- Johnson, Reason in the Balance
“Science is the search for the best naturalistic theories...”
... where a naturalistic theory abjures supernatural
causes.
Scientism
“Science is the arbiter of all knowable
truth, that there is nothing to be known
beyond what science delivers.”
Religion vs. Science
• Science is not committed to the
nonexistence of God.
• Science is committed to naturalistic
explanations.
• Science does not count any explanation
that appeals to God or to supernatural
phenomena as a scientific explanation.
1.
2.
3.
4.
5.
Creationism
Interplanetary or Cosmozoic theory
The Big Bang Theory
Spontaneous Generation
Biogenesis
*Intelligent Design
*The Anthropic Principle
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Life, humanity and all beings on earth were
created by a supernatural being
Opposes evolution because of the belief that
beings are “perfect” in their form and were
created as such
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
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Holds that the Genesis is infallibly true
Directly contradicts the Big Bang Theory and
the Theory of Evolution
Creationism is a scientific theory and should be
taught in the science curriculum as a
competitor to the theory of evolution.
The Cosmozoic Theory:
Meteors containing life?
Are we rejects
from another planet?
Intelligent Design
 Paley
“God’s Design could be seen in life...”
 John Wheeler
"A life-giving factor lies at the centre of the whole
machinery and design of the world."
The Anthropic Principle
 Proposed by astrophysicist and cosmologist
Brandon Carter from Cambridge University in
1973
 Presented at a conference held in Poland to
celebrate the 500th birthday of the father of
modern astronomy, Nicolaus Copernicus
The Anthropic Principle
"... the Anthropic Principle says that the
seemingly arbitrary and unrelated
constants in physics have one strange thing
in common--these are precisely the values
you need if you want to have a universe
capable of producing life."
Patrick Glynn
The Anthropic Principle
 Gravity
 Electromagnetism
 Nuclear force
 Mass of atomic particles
 Properties of water
 Carbon
Significant Events in the
Formation of Life
1.
2.
3.
4.
5.
6.
7.
8.
9.
Big Bang Theory
Condensation of Swirling gases into a solid mass
Formation of simple molecules – H2O, O2, N2, CH4,
NH3
Formation of Biomolecules – carbohydrates, fatty
acids, proteins, nucleotides
Formation of Coacervates
Formation of the first heterotroph prokaryote
Formation of the first autotrophic prokaryote
Formation of the eukaryotic cell
Formation of the multicellular organisms
Work by Miller and Oparin
The Coacervate Theory
• Colloidal suspension of
macromolecules
• May have properties
that enabled them to
form protocells
• Due simply to physical
and chemical
phenomena; not
selective
Characteristics of Coacervates
1. Identity – each one has a unique mixture of
biomolecules; properties of clay
2. A water film acts as a barrier like a cell
membrane
3. Grows in size
4. When large enough, it breaks down into small
globules with the same traits as that of the
“parent”
Spontaneous Generation vs. Biogenesis
1. Aristotle
2. Jean Baptiste Von
Helmont
3. Anton von
Leeuwenhoek
4. John Needham
1. Francesco Redi
2. Lazarro Spallanzani
3. Louis Pasteur
Aristotle for Spontaneous Generation
• Observed the similarity of inanimate
environmental structures with semblance to
certain living things (geese from trees, lambs
from melons)
• This theory is based on philosophical concepts
and limited scientific facts and instrumentation
Von Helmont for Spontaneous Generation
• Wheat kernels + dirty shirt + 21 days = mice
• Appearance of maggots in meat
• Appearance of beetles and wasp in cow dung
• Appearance of mice from caked mud
Francesco Redi for Biogenesis
• No maggots grew on
container with full
covering
• Set-up covered with
cheese cloth still
developed maggots
on meat
Leeuwenhoek for Spontaneous Generation
• Invented the
microscope and
observed small
moving forms he
called animalcules.
• Observed in dirty
canal water and teeth
scrapings
John Needham for Spontaneous Generation
• Boiled meat broth  transferred container 
incubate  cloudy broth
• Conclusion: Broth gave rise to animalcules
Spallanzani for Biogenesis
• Repeated the experiment of John Needham with
two difference: (a) container was covered and (b)
the broth not transferred
• No growth was observed
• Argument from scientist supporting spontaneous
generation: The cover prevented the essence of
life from the air to cause life to form in the
container
Louis Pasteur for Biogenesis
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•
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Used a swan neck flask
The broth was boiled and allowed to cool
No growth
Water trapped in the neck prevent microbes from
contaminating the broth
Manifestation of Life
1.
2.
3.
4.
5.
6.
Cellular Organization
Metabolism
Reproduction
Growth
Responsiveness or Irritability
Development or Evolution
Levels of Organization
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 Systems
Biosphere
Ecosystem
Community
Population
Multi-cellular and
single cell organisms
 Organs
 Tissue
 Cells
 Organelle
 Molecules
 Atoms
 Subatomic particles