Transcript II. The History of Evolutionary Thought

BIO55: Population Genetics and Evolution
What is Evolution?
What is Evolution?
I. Definitions
What is Evolution?
I. Definitions
A. youze guys
What is Evolution?
I. Definitions
A. youze guys
B. References
What is Evolution?
I. Definitions
A. youze guys
B. References
1. Darwin - "descent with modification"
2. Ridley - "change in a lineage of populations between
generations"
3. Futuyma - "a change in the properties of populations of
organisms, or groups of such populations, over
generations“
4. Freeman and Herron: “changes in allele frequencies over
time"
What is Evolution?
I. Definitions
2. Key Elements
1. Populations evolve – individuals develop.
What is Evolution?
I. Definitions
2.Key Elements
2. - Evolution is an observable phenomenon:
heritable change in a population over generations. This may
be observed at the genetic level, in the genetic structure of
the population, or may also be reflected in the physiological,
morphological, or behavioral traits affected by this genetic
change. We might term this "Lineage Evolution".
What is Evolution?
I. Definitions
2.Key Elements
3. - with known, observable causes:
the genetic structure of a population changes as a function
of selection, drift, mutation, migration, and non-random
mating.
What is Evolution?
I. Definitions
2.Key Elements
4. - and known, observable results:
As the genetic structure of a population changes over
generations, it can become different (diverge) from other
populations. These differences may mean that the
populations can no longer breed, and they become
biologically distinct entities - different species. We term this
"Radiational Evolution".
Why is reproductive isolation such a good definition of
‘species’, if by “species” we are trying to identify a biological
unit that is different from another biological unit?
II. The History of Evolutionary Thought
(Mayr, E. 1982. The Growth of Biological Thought)
At one time, there were no scientists, theologians, or historians.
There were just philosophers that studied everything, using one
way of thinking. That has changed, as we will see....
II. The History of Evolutionary Thought
A. Early Greeks
Pantheon of meddlesome gods that controlled
every aspect of nature and human experience; even took
humans for mating (produced the heroes).
Prometheus fashions humans out of earth and
water, and Athena gives humankind a soul
II. The History of Evolutionary Thought
B. Ionian School
Anaximander (610-546 bc); life
comes from water; first humans
remained as embryos in fish and
came forth as adults - had to come
from other organisms because of
prolonged developmental period
of dependancy.
II. The History of Evolutionary Thought
B. Ionian School
Anaximander (610-546 bc); life
comes from water; first humans
remained as embryos in fish and
came forth as adults - had to come
from other organisms because of
prolonged developmental period
of dependancy.
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
-Valued observation and testing rather than pure logic
- "cut-it-open-and-see"
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
-Valued observation and testing rather than pure logic
- "cut-it-open-and-see"
- Believed in use and disuse and inheritance of acquired
traits; so accepted change within a "family".
- Close to an evolutionary approach
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
- trained in Pythagorean school; philosopher not naturalist
- UNIVERSAL PHILOSOPHY (four dogmas)
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
- trained in Pythagorean school; philosopher not naturalist
- UNIVERSAL PHILOSOPHY (four dogmas)
- Essentialism: (essences perfect; material world is an
imperfect reflection of these perfect essences (eidos). Wall
of the cave analogy; triangle example
- Universal Harmony: essences form a perfect whole
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
- trained in Pythagorean school; philosopher not naturalist
- UNIVERSAL PHILOSOPHY (four dogmas)
- Essentialism: (essences perfect; material world is an
imperfect reflection of these perfect essences (eidos). Wall
of the cave analogy; triangle example
- Universal Harmony: essences form a perfect whole
- Demi-Urge: creative force that made the essences
- Soul: non-corporeal "spark of life" in living systems;
maximized in humans.
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
- trained in Pythagorean school; philosopher not naturalist
- UNIVERSAL PHILOSOPHY (four dogmas)
- Essentialism: (essences perfect; material world is an
imperfect reflection of these perfect essences (eidos). Wall
of the cave analogy; triangle example
- Universal Harmony: essences form a perfect whole
- Demi-Urge: creative force that made the essences
- Soul: non-corporeal "spark of life" in living systems;
maximized in humans.
- became the bedrock of western civilization for 2000 years!
Mayr states: "It took more than 2000 years for biology,
under the influence of Darwin, to escape the paralyzing
grip of essentialism...the rise of modern biology is, in part,
hey!
the emancipation from Platonic thinking".
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
3. Aristotle (384-322 bc)
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
3. Aristotle (384-322 bc)
- Plato's student. The first great philosopher interested in
biology. described 100’s of species and fossils
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
3. Aristotle (384-322 bc)
- Plato's student. The first great philosopher interested in
biology. described 100’s of species and fossils
- wrote books on anatomy, reproductive biology, and life
histories
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
3. Aristotle (384-322 bc)
- Plato's student. The first great philosopher interested in
biology. described 100’s of species and fossils
- wrote books on anatomy, reproductive biology, and life
histories
- an empiricist; used observation to answer questions, not
reason, alone
- harmonious whole still static; fixed species from simple to
complex in a great chain of being "Scala naturae"
II. The History of Evolutionary Thought
C. 2nd Greek School
1. Hippocrates (450-377 bc)
2. Plato (427-347 bc)
3. Aristotle (384-322 bc)
Major conclusion was Platonic essentialism
II. The History of Evolutionary Thought
D. The Impact of Christianity
World View:
- Single complete, harmonious creation by Christian God
II. The History of Evolutionary Thought
D. The Impact of Christianity
World View:
- Single complete, harmonious creation by Christian God
- Static, unchanging
II. The History of Evolutionary Thought
D. The Impact of Christianity
World View:
- Single complete, harmonious creation by Christian God
- Static, unchanging
- Plenitude: created in totality and perfection
II. The History of Evolutionary Thought
D. The Impact of Christianity
World View:
- Single complete, harmonious creation by Christian God
- Static, unchanging
- Plenitude: created in totality and perfection
- no breaks in Aristotle's scale of nature:
extending from humans to priest to bishop,
cardinal, pope, angels, God
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
- 1488 - Dias - Rounds Cape of Good Hope without burning!
- 1492 - Columbus - "New World"
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
1. Nikoli Copernik (1473-1543)
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
1. Nikoli Copernik (1473-1543)
2. Galileo Galilei (1564-1642)
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
1. Nikoli Copernik (1473-1543)
2. Galileo Galilei (1564-1642)
- nature is matter in motion, governed by mechanistic laws
- "measure what can be measured and make measureable that
which can not be measured"
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
1. Nikoli Copernik (1473-1543)
2. Galileo Galilei (1564-1642)
- nature is matter in motion, governed by mechanistic laws
- "measure what can be measured and make measureable that
which can not be measured"
- Empiricist - dependency on observation and testing, not
authority. THE BIRTH OF THE EXPERIMENTAL
METHOD. So now we have science, with reductionism and
the experimental method
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
5. Isaac Newton (1642-1727)
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
5. Isaac Newton (1642-1727)
- reasoned that the forces keeping planets in their orbits
(corrected to ellipses by Kepler) was the same that caused
attraction of terrestrial objects to earth (apple); and could be
explained by Galileo’s physics and laws of motion.
COMPARATIVE METHOD
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
5. Isaac Newton (1642-1727)
- reasoned that the forces keeping planets in their orbits
(corrected to ellipses by Kepler) was the same that caused
attraction of terrestrial objects to earth (apple); and could be
explained by Galileo’s physics and laws of motion.
COMPARATIVE METHOD
- force varies as a product of the masses, and is inversely
related to the square of the distance between them
II. The History of Evolutionary Thought
E. The Renaissance (1400-1700)
1. Voyages of Discovery
2. Scientific Revolution
a. Astronomy and Physics
b. The Age of the Earth