Transcript The Nature of Science and the Science of Nature - Tri

The Nature of Science and the
Science of Nature
• Read 274-298
• Pay attention to “overview” pg 276 and
290
4 goals in the investigation of zoology
(and other life sciences)
• 1. Cataloguing diversity (Taxonomy)
• 2. Explaining the functions of the body
(Anatomy Physiology)
• 3. Relating environmental influences to
forms (Ecology)
• 4. Understanding patterns and processes
in the world. Ex. Inheritance,
photosynthesis, fossil record, erosion,
volcanism,)
EVOLUTION
• fundamental unifying concept in biology. A
great variety of observations can be
explain because of this theory
• - doesn’t really comment on origins
• - all organisms are related by genealogy
(ancestry)
• - "descent with modification " Darwin
(features of a population changeover time
in response to environmental conditions)
I. THE EVOLUTION VS.
CREATION DEBATE
• A. The theory of
EVOLUTION has
stirred much SOCIAL
controversy in the past
• The Scopes Monkey
Trial
• "God, Darwin and
Dinosaurs” video
•
•
Begin video
(Show 1st 20 min. up to Karl Popper)
IN a nut shell , here is the conflict…
•
Supernatural
creation of the
universe and its
contents
• vs.
• natural processes
originating, and
modifying life to the
point we see it
today.
Arkansas LAW 590
"Balanced treatment law"
• Required that creationist accounts be
taught in biology classes because
• “In the beginning, God created the
Heavens and the Earth” is also a theory.
• This Law was struck down on January
5th,1982.
• The video will help explain why Judge
Overton made that ruling.
• B. A semantic problem (a problem with the
definition of the word) THEORY
• According to creationists--- Creation is
as valid an explanation of the origin of
life as evolution
THEORY
• - A TESTABLE EXPLANATION OF A
BROAD RANGE OF RELATED
PHENOMENA. IN MODERN SCIENCE,
ONLY EXPLANATIONS THAT HAVE
BEEN EXTENSIVELY TESTED AND CAN
BE RELIED UPON WITH A VERY HIGH
DEGREE OF CONFIDENCE ARE
ACCORDED THE STATUS OF A
THEORY.
examples
• The Cell Theory
• The Atomic Theory
• Continental Drift
DEFINITIONS OF OTHER
IMPORTANT WORDS
• LAW- a statement that describes the behavior of
some particular thing or set of things within the
natural world, with an adequately thorough
history of successful scientific replication.
• HYPOTHESIS- an idea or explanation for
something that is based on known facts but has
yet been proven
• FAITH - a belief in the absence of fact or data
• THEORY- a belief based on data or fact
• Don’t write this 1st sentence
• Theory: A theory is an explanation of a set
of related observations or events based
upon proven hypotheses and verified
multiple times by detached groups of
researchers. One scientist cannot
create a theory; he can only create
a hypothesis. A theory is more like
a scientific law than a hypothesis.
• Don’t write this 1st sentence
• Hypothesis: This is an educated guess
based upon observation. It is a rational
explanation of a single event or
phenomenon based upon what is
observed, but which has not been proved.
Most hypotheses can be supported
or refuted by experimentation or
continued observation.
• Scientific Law: This is a statement of fact meant to
explain, in concise terms, an action or set of actions.
It is generally accepted to be true and universal, and can
sometimes be expressed in terms of a single
mathematical equation. Scientific laws are similar to
mathematical postulates. They don’t really need any
complex external proofs; they are accepted at face value
based upon the fact that they have always been
observed to be true.
• Specifically, scientific laws must be simple, true,
universal, and absolute. They represent the cornerstone
of scientific discovery, because if a law ever did not
apply, then all science based upon that law would
collapse.
• Some scientific laws, or laws of nature, include the law of
gravity, Newton's laws of motion, the laws of
thermodynamics, Boyle's law of gases, the law of
conservation of mass and energy, and Hook’s law of
elasticity.
Reference page
• The biggest difference between a law and
a theory is that a theory is much more
complex and dynamic. A law governs a
single action, whereas a theory explains
an entire group of related phenomena
C. The Creationists views (be able to
distinguish between the two approaches)
• 1. CREATIONISM
• -supernatural creation of the universe and
its contents
• - literal interpretation of the Bible
• - short history of the earth
• 2. SCIENTIFIC CREATIONISM
• scientific evaluation of data reveals that
• - the earth is young (other methods of
dating are wrong)
• - fossils appear at the same time (humans
and dinosaurs)
• - supports the Biblical account of creation
Show 2nd 20 minutes of video, end at mosquito larva
D. A simple contrast table
•
EARTH
SPECIES
EVOLUTION
OLD
CHANGED
VS.
CREATIONISM
YOUNG
UNCHANGED
ORIGIN
GRADUAL
OF SPECIES
ALL AT ONCE
CAUSE
•
INTELLIGENT
DESIGN
NATURAL
PROCESSES
II WHAT SCIENCE IS (and why
creation science is not science)
• What is with-in the realm of science and
what is not?
• What are the methods of science?
• Science is, what scientists do!
• 1. Classify
• 2. Understand
• 3. Unify the objects and phenomena of the
material world
A. Characteristics of Scientific
Investigation
• 1. Materialism- GROUNDED IN THE LAWS
OF NATURE such as gravity, magnetism,
entropy, strong and weak nuclear forces
• 2. Testability- dependent parts and be
individually tested for validity.
Events can be measured, interpreted, extrapolated
(applied to a broader range of experiences)
ex. DNA changes = hereditary change,
nuclear decay = dating the age of rocks
• 3. Flasifiability- the potential to be proven
wrong
• the approach to solving a problem is most
important, not the final result.
• repeatable experiments
• data= facts
• conclusions are only as good as the data
• results are provisional (temporary)• not a problem because new information is
always being accumulated
• 4. Peer review of research- other experts
critiqueresearch before allowing
publication
Show final 20 min segment of video
•
•
•
•
•
B. Appropriate and inappropriate questions
NOT
POSSIBLE
1. morality
1. What is light?
2. ethics
2. Why do we see stars?
3. free will
3. How deep is the
ocean?
• 4. imagination
4. What is needed for
proper human growth?
• 5. spiritual
5. What are the
products of combustion?
• 6. metaphysical
6. How fast can a zebra
{GHOSTS}
run?
C.
Fallacy of Creation-Science-
• they already have an answer before the
facts are discovered
• the data will not change their conclusion
• creation cannot be wrong
• research is not published in peer reviewed
journals
D. Intelligent Design (ID)- latest
form of Creationism
• Suggests life is too complex to have
originated and developed by chance.
• Therefore it must have been “designed”
• Recent battle about the science standards
in Ohio
• Court ruling in Dover, Pennsylvania
IV THE CORE OF MODERN
BIOLOGY #2 EVOLUTION
• We don't often think of the questions that
biologists are trying to answer.
• They are responses to observations of the
natural world.
1. UNITY - why do organisms look
similar?
• Why the same 20 amino acids?
• why do all organisms possess the same DNA
and RNA?
• why is energy in the form of ATP and GTP?
2. DIVERSITY
• how did we get 30
million species?
• What drives them to
diversify?
• They are all unique
from large to small.
3. BIOLOGICAL ADAPTATIONS
• why do organisms
possess features that
help them survive in
their area?
• How do bacteria
become antibiotic
resistant?
• How long does it
take?
4. HISTORY
• What happened in the
past?
• We didn't witness the
events but can we
figure out the event in
the past?
• Ex. fossils, geological
formations, extinction,
ice ages
V The Logic of Natural Selection
pg 28
Complete work sheet from the binder “The Theory of Evolution”
What are the basic components of
Darwinian Evolution by Natural
Selection?
• FACTS
• 1. Superfecundity- (means overproduction of offspring)
• resources grow arithmetically 1,2,3,4,5,6,7,8
• populations grow geometrically 1,2,4,8,16,32,64
• 2. Individual variability
• 3. Heritability
Theory of Natural Selection
• adaptation to local circumstances
• not towards greater complexity
• 1) Competition for Resources
Thomas Malthus
ex. economist
• 2) Survival in part is determined by
characteristics, characteristics can be passed.
Therefore the next generation has more
members with the particular characteristics that
helped the original survive
• 3) The character and composition of the
population changes. Gene frequencies
change.
• (evolution is occurring)
(individuals don't evolve, populations do)
Evidence of relatedness
• Example: Transitional forms in the fossil
record
Hypothesis: If terrestrial vertebrates (tetrapods)
evolved from lobe-finned fish (sarcopterygians), then
there should be transitional forms that possess traits
that are intermediate.
Previously identified
transitional forms
From Ahlberg and Clack, Nature 2006
General Methods
• Scientists looked
specifically for the
transitional form of
interest by sampling…
From
Daeschler
et al., 2006
– Appropriate habitats
(stream system)
– Appropriate geologic time
(early Late Devonian =
385-376mya)
http://tiktaalik.uchicago.edu/photos.html
They found
Tiktaalik roseae!
http://tiktaalik.uchicago.edu/photos.html
From Ahlberg and Clack, Nature 2006
From Daeschler et al., Nature 2006
http://tiktaalik.uchicago.edu/photos.html
From Shubin et al.,
Nature 2006
Summary
• The study of and the evidence for
evolution clearly fits within the scientific
framework.
• We use current evolutionary theory to
make and test hypotheses
• There are many thousands of examples of
evidence for evolution
What data from whole
genome sequencing can tell
us about evolution of humans
Example: the
Evolutionary Hypothesis
of Common Ancestry
Chromosome Numbers in
the great apes:
human (Homo)
chimpanzee (Pan)
gorilla (Gorilla)
orangutan (Pogo)
46
48
48
48
Testable prediction:
If these organisms share a common
ancestor, that ancestor had either
48 chromosomes (24 pairs) or
46 (23 pairs).
Ancestral
Chromosomes
Chromosome Numbers in
the great apes
(Hominidae):
human (Homo)
chimpanzee (Pan)
gorilla (Gorilla)
orangutan (Pogo)
Fusion
Homo sapiens
Inactivated
centromere
46
48
48
48
Telomere
sequences
Centromere
Telomere
Testable prediction:
Common ancestor had 48 chromosomes (24 pairs) and
humans carry a fused chromosome; or ancestor had 23
pairs, and apes carry a split chromosome.
Human Chromosome #2 shows the exact
point at which this fusion took place
Homo sapiens
Inactivated
centromere
Telomere
sequences
Chr 2
“Chromosome 2 is unique to the human lineage of
evolution, having emerged as a result of head-tohead fusion of two acrocentric chromosomes that
remained separate in other primates. The precise
fusion site has been located in 2q13–2q14.1 (ref.
2; hg 16:114455823 – 114455838), where our
analysis confirmed the presence of multiple
subtelomeric duplications to chromosomes 1, 5, 8,
9, 10, 12, 19, 21 and 22 (Fig. 3; Supplementary
Fig. 3a, region A). During the formation of human
chromosome 2, one of the two centromeres
became inactivated (2q21, which corresponds to
the centromere from chimp chromosome 13) and
the centromeric structure quickly deterioriated
(42).”
Hillier et al (2005) “Generation and Annotation of the DNA
sequences of human chromosomes 2 and 4,” Nature 434: 724 – 731.
• STUDY GUIDE
• Define Creationism, Creation Science, Evolution,
Natural Selection, theory, law, hypothesis
• Contrast Evolutionists and Creationists view of
earth and its components.
• Describe the history, circumstances and
outcome of the "Scopes Monkey Trial"
• List 4 components of a scientific investigation
• List 4 main questions biologists ask
• Describe Evolution by Natural Selection (give
Darwin’s facts, evidence, and argument)
• Define Intelligent design