The Nature of Science and the Science of Nature

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The Nature of Science and the Science of Nature

• Read 274-298
• Pay attention to overview pg 276 and 290

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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,)

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EVOLUTION

• fundamental unifying concept in biology. A great
  variety of observations can be explain because of
  this theory
• - doesnt 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)

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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)

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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.

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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.

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• 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

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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.

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examples

• The Cell Theory
• The Atomic Theory
• Continental Drift

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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

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• Dont 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.

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• Dont 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.

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• 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 dont 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
  Hooks law of elasticity.

Reference page
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• 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

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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

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Show 2nd 20 minutes of video, end at mosquito
larva

• 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

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D. A simple contrast table

• EVOLUTION VS.
  CREATIONISM
• EARTH OLD YOUNG
• SPECIES CHANGED UNCHANGED
• ORIGIN GRADUAL ALL AT ONCE
• OF SPECIES
• CAUSE NATURAL
  INTELLIGENT
• PROCESSES DESIGN

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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!

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• 1. Classify
• 2. Understand
• 3. Unify the objects and phenomena of the
  material world

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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

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• 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

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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?

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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

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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

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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.

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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?

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2. DIVERSITY

• how did we get 30 million species?
• What drives them to diversify?
• They are all unique from large to small.

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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?

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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

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V The Logic of Natural Selection pg 28
Complete work sheet from the binder The Theory
of Evolution
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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

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Theory of Natural Selection

• adaptation to local circumstances
• not towards greater complexity
• 1) Competition for Resources Thomas Malthus
  ex. economist

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• 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

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• 3) The character and composition of the
  population changes. Gene frequencies change.
• (evolution is occurring)
  (individuals don't evolve, populations do)

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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.
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Previously identified transitional forms
From Ahlberg and Clack, Nature 2006
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General Methods

• Scientists looked specifically for the
  transitional form of interest by sampling
• Appropriate habitats (stream system)
• Appropriate geologic time (early Late Devonian
  385-376mya)

From Daeschler et al., 2006
http//tiktaalik.uchicago.edu/photos.html
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They found Tiktaalik roseae!
http//tiktaalik.uchicago.edu/photos.html
From Ahlberg and Clack, Nature 2006
From Daeschler et al., Nature 2006
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http//tiktaalik.uchicago.edu/photos.html
From Shubin et al., Nature 2006
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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

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What data from whole genome sequencing can tell
us about evolution of humans
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Example the Evolutionary Hypothesis of Common
Ancestry Chromosome Numbers in the great
apes human (Homo) 46chimpanzee
(Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48
Testable prediction If these organisms share a
common ancestor, that ancestor had either 48
chromosomes (24 pairs) or 46 (23 pairs).
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Ancestral Chromosomes
Chromosome Numbers in the great apes
(Hominidae) human (Homo) 46chimpanzee
(Pan) 48gorilla (Gorilla) 48orangutan (Pogo) 48
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.
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Human Chromosome 2 shows the exact point at
which this fusion took place
Chromosome 2 is unique to the human lineage of
evolution, having emerged as a result of
head-to-head fusion of two acrocentric
chromosomes that remained separate in other
primates. The precise fusion site has been
located in 2q132q14.1 (ref. 2 hg 16114455823
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).
Homo sapiens
Inactivated centromere
Telomere sequences
Chr 2
Hillier et al (2005) Generation and Annotation
of the DNA sequences of human chromosomes 2 and
4, Nature 434 724 731.
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• 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
  Darwins facts, evidence, and argument)
• Define Intelligent design