Biology 178 Biology, Fall 2008
Instructor: Dr. Kurt Toenjes,
Phone: 896-5940
Room: 133 Science Hall
Email: [email protected]
Textbook: BIOLOGY, 8th Edition by Raven et al.
•Course Introduction and Objectives:
•Assessment:
•Grading:
•Academic Honesty:
•Attendance:
•Schedule:
Course Introduction
Labs Start Next Week
Lab Manual available in bookstore – buy it before class.
Required Texts:
Biology – Raven et al. (8th Ed.)
Laboratory manual – Vodopich and Moore (8th Ed.)
Grading: REFER TO SYLLABUS – save this in an
organized location, it is your reference guide.
Course Introduction
How to succeed in Biology 178:
1)
2)
3)
4)
Study every single day, including weekends
Stay organized
Plan ahead for exams
Come to class!
•
•
•
Take notes, ask questions
Use the text as a supplement to the lectures
Review lectures on the course website
5) Come see me with questions…before the test
6) Make sure I know your name!
Chapter 1
The Science of Biology
LECTURE OUTLINE
I. Properties of Life
II. Hierarchical Organization of Life
III. The Nature of Science
IV. Stages of a Scientific Investigation
V. What is Scientific Theory
VI. Unifying Themes in Biology
A replica of the Beagle.
What is Biology?
• Study of life
• Search for order in the
natural world
• Discovery of new
relationships
• Learning the working
rules that allow life to
exist
The Importance of Biology
I. Properties of Life
Basic characteristics of living
organisms
a. cellular organization
Oil and Water: Alive or not alive?
b. order
c. sensitivity
d. growth, development, and reproduction
e. energy utilization
f. evolutionary adaptation
g. homeostasis
Alive or not alive?
I. Properties of Life
Basic characteristics of living
organisms
a. cellular organization
Oil and Water: Alive or not alive?
b. order
c. sensitivity
d. growth, development, and reproduction
e. energy utilization
f. evolutionary adaptation
g. homeostasis
Alive or not alive?
II. Hierarchical Organization of Life
Life’s levels of organization define the scope of biology
II. Hierarchical Organization of Life
Emergent properties
New properties arise at each higher level
Paramecium
III. The Nature of Science
1. Hypothesis Testing!
Hypothesis (= assumption in ancient Greek) is a
proposed explanation for a phenomenon
(an educated guess)
III. The Nature of Science
2. Reasoning
a. Deductive Reasoning (Predictions)
Apply general principles to predict specific results
e.g. If organisms are composed of cells & humans are organisms, then
humans are composed of cells
b. Inductive Reasoning
Use specific observations to construct general
principles
e.g. If animals are composed of cells & plants are composed of cells, &
fungi are composed of cells, than perhaps all living things are
composed of cells
IV. Stages of a Scientific Investigation
Observation
All science begins with an observation.
!
Question
!
Hypothesis(es)
A hypothesis is a suggested explanation
that accounts for an observation.
!
Prediction(s)
!
Controlled Experiment
!
An experiment is used to test a
hypothesis, and/or eliminate one or
more multiple hypotheses
Conclusion
IV. Stages of a Scientific Investigation
IV. Stages of a Scientific Investigation
Steps in the scientific method:
(1) Observation
Francesco Redi in 1600’s!
!Maggots appear on fresh meat left uncovered.
!Flies swarm over raw meat
(2) Hypothesis
A tentative testable explanation of an observed event.
! Maggots appear on fresh meat left uncovered
because flies land on the meat and lay eggs.
IV. Stages of a Scientific Investigation
Steps in the scientific method ...
(3) Experiment
a study to test a hypothesis
Simple experiments
Test single variable AT A TIME
– Experimental Variable
– AKA the “Treatment”
Control all other variables
– Hold them constant in “controls”
What were his results?
Maggots
No maggots
IV. Stages of a Scientific Investigation
Steps in the scientific method ...
(4) Conclusion
In this case, the hypothesis is
supported by the results of the
experiment
Maggots
No maggots
IV. Stages of a Scientific Investigation
O"Q " H " P " Controlled Experiments " Conclusions
!
Manuscript preparation for publication
!
Peer Review
!
Publication
!
Replication by other scientists
!
Acceptance by the scientific community
IV. Stages of a Scientific Investigation
Science is a human endeavor.
Real scientific advances often
involve:
–
–
accidents and insight
lucky guesses
–
controversies between scientists
i.e. Discovery of penicillin by
Alexander Fleming, 1928
Penicillin prevents the growth of staphylococci bacteria,
an organism causing serious infection at that time
Theory: Scientific versus general
Theory: Scientific versus general
In one episode of 'Cheers', Cliff is seated at the bar describing the Buffalo Theory to
Norm. "Well you see, Norm, it's like this... A herd of buffalo can only move as
fast as the slowest buffalo. And when the herd is hunted, it's the slowest and
weakest ones at the back that are killed first. This natural selection is good for
the herd as a whole, because the general speed and health of the whole group
keeps improving by the regular killing of the weakest members.”
1.
A set of statements or principles devised to explain a
group of facts or phenomena, especially one that has been
repeatedly tested or is widely accepted and can be used to
make predictions about natural phenomena.
Theory: Scientific versus general
In one episode of 'Cheers', Cliff is seated at the bar describing the Buffalo Theory to
Norm. "Well you see, Norm, it's like this... A herd of buffalo can only move as
fast as the slowest buffalo. And when the herd is hunted, it's the slowest and
weakest ones at the back that are killed first. This natural selection is good for
the herd as a whole, because the general speed and health of the whole group
keeps improving by the regular killing of the weakest members.”
“In much the same way, the human brain can only operate as fast as the
slowest brain cells. Now, as we know, excessive intake of alcohol kills brain cells.
But naturally, it attacks the slowest and weakest brain cells first. In this way,
regular consumption of beer eliminates the weaker brain cells, making the brain a
faster and more efficient machine. And that, Norm, is why you always feel
smarter after a few beers...."
1.
A set of statements or principles devised to explain a
group of facts or phenomena, especially one that has been
repeatedly tested or is widely accepted and can be used to
make predictions about natural phenomena.
2.
An assumption based on limited information or knowledge;
a conjecture.e; a conjecture.
V. What is a Scientific Theory?
A theory is:
– a hypothesis supported by a wealth of
scientific evidence
– interconnected concepts, supported by
experimental evidence
– solid ground of science
– capable of predicting future occurrences or
observations of the same kind
V. What is a Scientific Theory?
Examples of Theories in Science:
1. Cell Theory
2. Theory of Relativity
3. Theory of Evolution
Theory: Scientific versus general
Cell theory
Theory: Scientific versus general
Stem Cell theory
Theory: Scientific versus general
Stem Cell use in wound repair
Theory: Scientific versus general
Stem Cell use in wound repair
Theory: Scientific versus general
Stem Cell use in wound repair
Debate is an important part of science
Not a current scientific debate
• Natural selection and evolution versus Creative Design
Not a current scientific debate
• Natural selection and evolution versus Creative Design
V. What is a Scientific Theory?
Example of the Development of a Theory: Evolution
Accepted “Belief” in 1831: Species have been specifically
created and are unchangeable over time.
Darwin’s Evidence to the Contrary:
Fossil record
Geographical Variability
Island Modifications
V. What is a Scientific Theory?
The Basics of the Theory of Evolution
Darwin & Wallace 1800’s
(1) Genetic variation: exists among members of a
population
(2) Inheritance of variations: parents to offspring
(3) Natural selection: Enhanced survival/reproduction
of organisms with adaptations to survive
!Present-day organisms descended, with
modification, from pre-existing forms
…or…‘Change over time’
V. What is a Scientific Theory?
Further Evidence Supporting the Theory of Evolution:
1. The Fossil Record
2. The Age of the Earth
3. The Mechanisms of Heredity
4. Comparative Anatomy
5. Molecular and Phylogenetic Evidence (DNA)
Figure 1.13
V. What is a Scientific Theory?
What is Biology?
Unifying Themes of Biology
1. Cell theory
2. Molecular basis of inheritance
3. Evolution
VI. Unifying Themes in Biology
What is Biology?
1. Cell Theory
Robert Hooke (1665): Discovered cells
Schleiden and Schwann (1839): “All living things are
composed of cells”
Modern Cell Theory: All living organisms are made of cells,
and all living cells come from other living cells.
2. Molecular basis of inheritance
DNA encodes genes which make-up and control living
organisms. Heredity is dependent on the faithful copying of
the cell’s DNA into daughter cells.
3. Evolution
! conservation
Some fundamentally important characteristics of earlier
organisms are preserved and passed on to future generations.
e.g. Histones (chief proteins of chromatin)
! adaptation
Life-forms have evolved varying characteristics to adapt to varied
environments. This has resulted in incredible diversity.