Download Prologue Notes #2 - Mr. Palme`s Webpage

Introduction
to Biology
Prologue: The Molecular Perspective
Prologue: Packet #1
Biology in Your World
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Biology is believed to be the most influential
science of the 21st century
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Cancer cures?
Genetic engineering / counseling / cloning
Stem cells
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But, just because we can…should we?
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Prologue: Packet #1
Ethics and Biology
Using Knowledge Wisely

Ethics – a system of moral principles to
distinguish right from wrong
 What are your ethics based upon?

Public Policy – laws and regulations that
govern how science is applied
 What role do you play in deciding public
policy?
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Example
http://www.csmonitor.com/USA/Justice/2011/0429/Stem-cell-research-Court-gives-Obama-a-victory-but-policy-still-on-trial
Prologue: Packet #1
What is science?
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An organized way of using evidence to learn about the
natural world

The body of knowledge that scientists have accumulated
over time
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It is not based on belief or faith, magic, or legend but on
actual evidence.

Pseudoscience – associating real science to some supernatural
occurrence or pattern without evidence

EXs: Palm reading, Astrology, Alchemy, Intelligent Design

Daily Horoscope
Prologue: Packet #1
Important Scientific Skills

Observing – process of gathering information using your
senses in a careful, orderly way
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Inferencing – making a logical interpretation based on
prior knowledge or experience


Did not eyewitness
Example…
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Baby was asleep upstairs – heard a loud thump – heard crying
What inferences can we make?
http://www.philtulga.com/Riddles.html - Inferencing game
Prologue: Packet #1
The Scientific Process
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Analyzes problems through TESTING
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Hypothesis – possible explanation of observations that
are testable through experimentation or observation.


Theory – a repeatedly tested hypothesis that accurately
explains observations and predicts future occurrences.


“If….then”
Cell theory, gene theory
Laws – widely accepted and repeatedly tested theories

Newton’s Law, Thermodynamics
Prologue: Packet #1
Good Scientists….
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Are skeptics: they question existing ideas and new
hypotheses
Are open-minded: they are always willing to consider
new ideas when evidence demands it
Rely on basic natural laws: they understand that the
universe functions as a system of interacting processes
Repeat experiments: through an immense amount of
research a certain hypothesis might become so wellsupported that scientists consider it a theory
Keep up with new knowledge gained through research:
they continually revise and re-evaluate ideas.

NOTHING IS “FACT”
Prologue: Packet #1
What is Life?
A fundamental scientific question
Prologue: Packet #1
“Life is Organized”
Smallest / most simple
Atoms
C,H,O,N,P,S
Molecules
Organelles
Cells
Tissues
Organs
Organ Systems
Organism
Species
Population
Community
Ecosystem
Biome
Ex: Tundra, desert,
temperate forest
Biosphere
Largest / most complex
Prologue: Packet #1
How did life begin?
An Idea

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The Oparin-Haldane Hypothesis (1920s)
Verified by Miller-Urey (1953)
Built an apparatus to mimic early earth:
 Reducing atmosphere;
methane, ammonia, hydrogen
 Boiled water, shocked it, cooled it
 Atoms bumped together &
formed hydrocarbons and amino acids!
Prologue: Packet #1
Living things…
Are made up of units called CELLS
 Are based on a universal GENETIC code
 REPRODUCE
 GROW and DEVELOP
 CHANGE over time (evolve)
 Obtain & Use Materials and ENERGY
 Maintain an Internal BALANCE
= homeostasis
 RESPOND to their Environment
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Prologue: Packet #1
EVOLVE
Why does a duck have a rounded bill
and a heron have a long pointed bill?

All organisms are uniquely
adapted for their
environments.

Scientists know that over
long periods of time
organisms have changed or
adapted to better survive in
their environments.

They call this slow process of
change evolution.

Natural Selection: Those
best adapted survive and
Prologue: Packet #1
reproduce.
Life BEGINS…
CELLS with DNA are passed on through
REPRODUCTION
An organism GROWS and DEVELOPS to an age where it
can REPRODUCE.
Over time, subtle changes are introduced through
mutation of DNA. These changes are selected for,
leading to EVOLUTION of a population.
Prologue: Packet #1
A Mechanism for
Evolution: Science at
Work
The formulation of a Theory
An Example of The Scientific Process
Prologue: Packet #1
Jean Baptiste Lamarck (1744 – 1829)
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Organisms change over time by using or not using
certain features. These acquired characteristics are then
passed onto offspring
“Use or Disuse”
“If a male and a female increase the size of their
muscles through weight training, then their children will
be born with large muscles.”
Mr. Palmé
as a 5 yr
old
Prologue: Packet #1
Was
Lamarck
right?
Prologue: Packet #1
Charles Darwin (1809 – 1882)
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A naturalist on a 5-year voyage of the Beagle around the
world
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Observed numerous, diverse organisms
Influenced by the geologists, Charles Lyell and James
Hutton, who proposed uniformitarianism (everything in the
universe acts under the same laws of physics)
 Geological
forces existing in the past are similar to
the forces of today and in the future

Proposed the mechanism of evolution
 Natural Selection
Prologue: Packet #1
Theory of Natural Selection

Organism best suited (specific traits/characteristics) for
the environment would survive and reproduce.

The suitable traits would be passed on to their offspring.

The specific traits or characteristics are called
adaptations
Prologue: Packet #1
Is this how Evolution works?
Prologue: Packet #1
Survival of the Fittest

Thomas Malthus (economist) noticed that species
numbers exceed food supply

In order to pass on characteristics, an organism must eat
enough to live to reproduce.

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Ultimately, the only organisms alive are those with beneficial
adaptations
What are some adaptations?
Prologue: Packet #1
Darwin’s Predictions

If organisms with favorable variations are most likely to
survive and reproduce, then those organisms with
unfavorable variations would be less successful at
reproduction and die out.

If organisms with those favorable adaptations become
so different from members of the original species that
they can no longer reproduce together, then a new
species may have evolved.
Prologue: Packet #1
Was Darwin Right?

Whose to say but…
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Experiments repeatedly show same results
Descent with Modification – related organisms share a
common ancestor
 The greater the similarity between two groups of
organisms, the closer their relationship
 How is this studied today?
Prologue: Packet #1