Download Prologue - greinerudsd

Why should you care?
What is Science?
What is Biology?
What is Life?
Evolution – What does this major theory say?
Introduction to Biology
Prologue: The Molecular Perspective
Bio 391
Biology in Your World


Biology is believed to be the most influential science of
the 21st century
What are some of the ways biology impacts your life
now?

In the future?

But, just because we can…should we?
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?
Ethics in Biology






Stem cells in research/treatment
Prenatal genetic testing for diseases
Genetic testing for susceptibility
Biotechnology for altering self or offspring
Genetically modified (GM) food
What are some others?
Science as a way of Knowing
If you are a thinker, you question things you
observe and may not understand and you try to
find an answer. There are many ways to find
these answers. If you are a scientific thinker you
find your answer using the scientific method.
Example: Why is the sky blue?
What is science?

An organized way of using evidence to learn about the
natural world

The body of knowledge that scientists have accumulated
over time

It is not based on belief or faith, magic, or legend but on
actual evidence. It is concerned with the natural world,
not the supernatural world
This is pseudoscience

Important Scientific Skills

Observing – process of gathering information using your
senses in a careful, orderly way

Inferencing – making a logical interpretation based on
prior knowledge or experience

Example…
The Scientific Process

Analyzes problems through TESTS

Hypothesis – explanation of observations that are
testable through experimentation or observation.

“If….then”

Theory – a repeatedly tested hypothesis that accurately
explains observations and predicts future occurrences.

Laws – widely accepted and repeatedly tested theories

Can you name any?
Good Scientists….





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”
What is Life?
A fundamental scientific question
What is the difference between you and your desk?
Is a fallen apple alive?
“Life is Organized”
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
How did life begin?



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!
Early Life





Everything is just a bunch of atoms
Life began in the sea
Oxygen was not used for respiration
 How did Oxygen become plentiful?
Evolutionary tree
Classification system
Classification

Biologists group organisms to show similarities and
proposed relationships.
 Based on the Theory of Evolution
 Descent with Modification

Classification systems change with expanding
knowledge about new and well-known organisms
Kingdoms and Domains
Three Domain System (based on rRNA evidence)
Bacteria
Archaea
Eukarya
Six Kingdom System (based on rRNA evidence)
Bacteria
Archaea
Protista
Plantae
Fungi
Animalia
Traditional Five Kingdom System
Monera
Protista
Plantae
Fungi
Animalia
Humans =
.00009%
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
 RESPOND to their Environment

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
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 ‘s are selected for, leading
to EVOLUTION of a population.
Recap
How do the 8 characteristics of life apply
to you?
 What Kingdom do we belong to?
 What is a theory?
 What is ethics?

A Mechanism for Evolution:
Science at Work
P.5: The
formulation of a Theory
Jean Baptiste Lamarck (1744 – 1829)



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.”
Was
Lamarck
right?
Charles Darwin (1809 – 1882)


A naturalist on a 5-year voyage of the Beagle around the
world
Observed numerous, diverse organisms

Influenced by the geologists, Charles Lyell (1797-1875)
and James Hutton, who proposed uniformitarianism
 Geological forces existing in the past are similar to
the forces of today and in the future

Proposed the mechanism of evolution
 Natural Selection
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
Is this how Evolution works?
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.
Ultimately, the only organisms alive are those with
beneficial adaptations


What are some adaptations?
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.
Was Darwin Right?



________
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?
Recap
What is the difference between Lamarck
and Darwin’s ideas? (use an example)
 Give an example of an adaptation
 What is uniformitarianism?
 What makes a theory different than a
hypothesis?

Other Accepted Theories

Cell Theory: All organisms are composed of one or more
cells, and those cells have arisen from pre-existing cells

Gene Theory: The Central Dogma that
DNA  RNA  proteins. DNA is inherited and
expressed as protein traits.

Homeostasis: maintenance of a constant/dynamic
equilibrium