Transcript 3rd_301M-Lecture

Course Website:
Varanus eremius (Varanid)
Bookmark http://www.zo.utexas.edu/courses/bio301/
Download Syllabus from above site (Contract)
Exams, ground rules, discussion sections, textbook, etc.
Watch ‘Dance Monkeys Dance’ and ‘Domino Effects’ videos
Our one and only but much abused Spaceship
Ecology, environment, organismic units
Anthropocentrism, wilderness, what good are rattlesnakes?
Hierarchical structure of biological science, snobbery
First Exam: 18 Feb.
Second Exam: 31 Mar.
Third Exam: 5 May
Best 2 of above 3 = 40%
Discussion Sections 20%
Anolis
carolinensis
(Iguanid)
Final Exam: 13 May 9-12 AM: 40%
No “Extra points,
No “Make Up” Exams!
Final Grades are FINAL, non negotiable
Five Lizard Clades:
Sceloporus
Agamidae
440 species
Gekkota
7 Families
1536 species
Iguania
12 Families
1086 species
Scincidae
1600 species
Varanidae
75 species
Moloch
Ctenophorus
Phelsuma
Anolis
Ctenotus
Varanus
Ctenotus
Hierarchical Organization of the Biological Sciences
Molecular Biology
<—————— Integrative Biology——————————>
Snobbery
Proper motivation to do science is curiosity.
How do things work?
Assume an organized reality exists and that
objective principles can be formulated to reflect
this natural order (not faith based).
Common misconception that “truth”
and “proof” and even “facts” exist.
Nietzsche said “there are no facts,
only interpretation.”
Nietzsche
Proper motivation to do science is curiosity.
How do things work?
Assume an organized reality exists and that
objective principles can be formulated to reflect
this natural order (not faith based).
Common misconception that “truth”
and “proof” and even “facts” exist.
Nietzsche said “there are no facts,
only interpretation.”
Nietzsche
‘Just Another Monkey’
Sunrise
Sunset
Geocentric world view
X
X
Sunrise
Sunset
Geocentric world view
“Spinup”
“Spindawn””
“Spindown”
“Spindusk”
Solar system world view
Heliocentric world view
You are Here
Heliocentric world view
Most people consider a “fact” as “what really happened.”
However, Many “facts” are not so clean and simple -- most
involve varying levels of interpretation. Consider, for example,
the apparently simple fact that the Sun rises each morning.
Daily we receive new evidence confirming this fact. We can
be quite confident that the Sun will rise again tomorrow.
References to sunrise and sunset are based on now defunct
concept of a “flat Earth and moving Sun”. But our understanding
of cosmic events is greatly enhanced when instead of thinking
of the Sun as moving, it is viewed as fixed in space at the
center of a solar system, and the Earth is interpreted as a
rotating globe orbiting around a small star. Our vocabulary
hasn't caught up -- clearly, we should refer to “sunrise” as
“spinup” or “spindawn” and “sunset” as “spindown” or “spindusk.”
Our one and only Spaceship (there is no planet B)
Observation and Experiment are vital.
Scientists formulate hypotheses to explain
repeatable events. A hypothesis is tested by
confronting it with reality — if it fails, it is
discarded and replaced with another, hopefully
better, hypothesis.
In time, a well supported hypothesis becomes a
theory. The scientific method is self regulating:
poor hypotheses are continually replaced with
better ones as human knowledge expands and is
improved. We benefit immensely from past genius.
A sprinkling of past geniuses:
Socrates
DaVinci
Aristotle
Newton
Archimedes
Darwin
Euclid
Einsteinn
Archimedes
“The Method”
Archimedes (287-212 BC) “The Method”
Archimedes (287-212 BC) “The Method”
http://www.britannica.com/EBchecked/to
pic/32808/Archimedes - ref389152
Evolution is not synonymous with Natural Selection
Evolution is defined as any change in the gene pool
Agents of Evolution
•
Genetic Drift (random sampling)
•
Gene Flow (migration)
•
Mutation Pressure
•
Meiotic Drive (segregation distortion)
•
Natural Selection
Natural Selection = Differential Reproductive Success
“Struggle for Existence”
“Survival of the Fittest”
Selection results in Adaptation (other agents of evolution do not)
(Adaptation is conformity between organism and environment)
Natural Selection does not always
operate via Differential Mortality
Cautious long-lived tomcat
versus short-lived alley cat
The currency of Natural Selection
is progeny (offspring, babies)
Not beauty, brains, or brawn
If the ugly stupid and weak make
more babies, their genes prevail
Natural Selection does not always
operate via Differential Mortality
Cautious long-lived tomcat
versus short-lived alley cat
The currency of Natural Selection
is progeny (offspring, babies)
Not beauty, brains, or brawn
If the ugly stupid and weak make
more babies, their genes prevail
Darwinian Fitness = ability to perpetuate genes
in the gene pool
Natural Selection operates like an efficiency expert,
ferreting out the best way to perpetuate an organism’s
genes
Natural Selection is however short sighted
(does not “see” past the next generation!)
Natural Selection is the ultimate inventor: flight,
echolocation, celestial navigation, insulation, infrared
sensors, hypodermic needles, plus all sorts of
pharmaceuticals (antibiotics, analgesics, diuretics, hormone
mimics, laxitives, tranquilizers, etc.)
Natural Selection is the ultimate inventor:
flight, echolocation, celestial navigation,
insulation, infrared sensors, hypodermic
needles, plus all sorts of pharmaceuticals
antibiotics
Harry Greene
analgesics
diuretics
hormone mimics
laxatives
tranquilizers
Fer-de-Lance Bothrops asper
Nature versus Nurture Controversy
“Environmentally induced”
polymorphism
Daniel Otte
Kathy Williams
Syrbula, Chortophaga
Nature versus Nurture Controversy
“Environmentally induced” polymorphism
Canalization
Background
Color
Brown
Green
Brown
Brown
Green
Green
C H Waddington
Cepaea nemoralis Snails
Domain of Ecology
Simple versus multiple causality
8+ Billion
of us
8+ Billion
of us
Paul Ehrlich
8+ Billion
of us
8+ Billion
of us
Caribou
Pribolof Islands
Alaska
Caribou
Pribolof Islands
Alaska
Levels of Approach in Biology
• How? versus Why? Questions and Explanations
• Proximate and Ultimate Factors
• Mechanistic versus Strategic Perspectives
• Short-term versus long-term considerations
• Why do birds fly south in the autumn?
• Shorter day length triggers pituitary secretions that enhance
Wanderlust.
• Winter is predictable and reduces survival. Birds that tended to move
south escaped its icy clutches and survived to reproduce and left
more genes in the population gene pool.