Download Introduction Chapter 1

Introduction to Life
The Science of Biology
Biology is…
• The study of life…
…at all levels
Figure 1.6
Life is…
• a phenomenon observed in organized genetic
units and expressed as
Life is…
• a phenomenon observed in organized genetic
units and expressed as
– metabolism by individuals
Life is…
• a phenomenon observed in organized genetic
units and expressed as
– metabolism by individuals
– reproduction among individuals
Life is…
• a phenomenon observed in organized genetic
units and expressed as
– metabolism by individuals
– reproduction among individuals
– evolution of populations through time
Paradigm
Paradigm
• a pattern or an example of something
Paradigm
• a pattern or an example of something
• a mental picture or pattern of thought
Paradigm
• a pattern or an example of something
• a mental picture or pattern of thought
• the model that scientists hold about a
particular area of knowledge
• [Thomas Kuhn in The Structure of Scientific
Revolutions]
Organic Evolution is the Principle
Paradigm in the Biological Sciences
Organic Evolution is the Principle
Paradigm in the Biological Sciences
• the model that scientists hold about a
particular area of knowledge
Organic Evolution is the Principle
Paradigm in the Biological Sciences
• the model that scientists hold about a
particular area of knowledge
– an organizing concept
Organic Evolution is the Principle
Paradigm in the Biological Sciences
• the model that scientists hold about a
particular area of knowledge
– an organizing concept
– a principle
Organic Evolution is the Principle
Paradigm in the Biological Sciences
• the model that scientists hold about a
particular area of knowledge
– an organizing concept
– a principle
– an assumption
Organic Evolution is the Principle
Paradigm in the Biological Sciences
• the model that scientists hold about a
particular area of knowledge
– an organizing concept
– a principle
– an assumption
– a presupposition
Dueling Paradigms
Dueling Paradigms
Static Creation in
the Modern State
Dueling Paradigms
Static Creation in
the Modern State
vs. Evolution from a
Less-complex State
Dueling Paradigms
Static Creation in
the Modern State
Young Earth
vs. Evolution from a
Less-complex State
Dueling Paradigms
Static Creation in
the Modern State
Young Earth
vs. Evolution from a
Less-complex State
Ancient Earth
Dueling Paradigms
Static Creation in
the Modern State
vs. Evolution from a
Less-complex State
Young Earth
Recent Origin of Life
Ancient Earth
Dueling Paradigms
Static Creation in
the Modern State
vs. Evolution from a
Less-complex State
Young Earth
Ancient Earth
Recent Origin of Life
Ancient Origin of Life
Dueling Paradigms
Static Creation in
the Modern State
vs. Evolution from a
Less-complex State
Young Earth
Ancient Earth
Recent Origin of Life
Ancient Origin of Life
Discrete Species
Dueling Paradigms
Static Creation in
the Modern State
vs. Evolution from a
Less-complex State
Young Earth
Ancient Earth
Recent Origin of Life
Ancient Origin of Life
Discrete Species
Intergrading Species
The Puzzle of Nature
The Puzzle of Nature
Similarities
Differences
The Puzzle of Nature
Similarities
DNA is universal
Differences
All Organisms Share DNA Landmarks
Figure 1.8
The Puzzle of Nature
Similarities
DNA is universal
Differences
Genomes Differ
The Puzzle of Nature
Similarities
DNA is universal
Eukaryotic
metabolism
Differences
Genomes Differ
The Puzzle of Nature
Similarities
DNA is universal
Differences
Genomes Differ
Eukaryotic
metabolism
Prokaryotic
metabolism
The Puzzle of Nature
Similarities
DNA is universal
Differences
Genomes Differ
Eukaryotic
metabolism
Prokaryotic
metabolism
Structural
homologies
Vertebrate Forelimb Homologies
Figure 1.2
The Puzzle of Nature
Similarities
DNA is universal
Differences
Genomes differ
Eukaryotic
metabolism
Prokaryotic
metabolism
Structural
Homologies
Functional
adaptations
Functional
Adaptations
Figure 1.7
The “Evolution” of Evolution
The “Evolution” of Evolution
“Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.”
The “Evolution” of Evolution
“Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.”
The “Evolution” of Evolution
“Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.”
Darwin
The “Evolution” of Evolution
“Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.”
Darwin,
Erasmus (1731-1802) The Temple of Nature
The “Evolution” of Evolution
• Count George-Louis Leclerc de Buffon (17071788)
Perhaps structural similarities are due to
descent from a common ancestor with
similar characteristics
The “Evolution” of Evolution
• Count George-Louis Leclerc de Buffon (17071788)
Perhaps structural similarities are due to
descent from a common ancestor with
similar characteristics
• Jean-Baptiste de Lamarck (1744-1829)
Organisms change from generation to
generation as they inherit characteristics that
their parents acquired during their lives
The “Evolution” of Evolution
• Charles Darwin
The “Evolution” of Evolution
• Charles Darwin
Organisms reproduce more offspring than
can survive on available resources
The “Evolution” of Evolution
• Charles Darwin
Organisms reproduce more offspring than
can survive on available resources
Populations of organism exhibit heritable
variations in their characteristics
The “Evolution” of Evolution
• Charles Darwin
Organisms reproduce more offspring than
can survive on available resources
Populations of organism exhibit heritable
variations in their characteristics
Some characteristics make certain
individuals more likely to survive than
others
The “Evolution” of Evolution
• Charles Darwin
Given overpopulation/limited resources,
biological variation & differential survival:
The “Evolution” of Evolution
• Charles Darwin
Given overpopulation/limited resources,
biological variation & differential survival:
The characteristics of a population
change over time
The “Evolution” of Evolution
• Charles Darwin
Given overpopulation/limited resources,
biological variation & differential survival:
The characteristics of a population
change over time
This pattern of “natural selection” is
superimposed on the random processes of
survival and death
The “Evolution” of Evolution
• Mid 18th century - evolution was “in the air”
The “Evolution” of Evolution
• Mid 18th century - evolution was “in the air”
• Mid 19th century - natural selection
The “Evolution” of Evolution
• Mid 18th century - evolution was “in the air”
• Mid 19th century - natural selection
• Mid 20th century - The Modern Synthesis
The “Evolution” of Evolution
• Mid 18th century - evolution was “in the air”
• Mid 19th century - natural selection
• Mid 20th century - The Modern Synthesis
– genetics, biochemistry, embryology,
comparative anatomy, physiology, etc.
The “Evolution” of Evolution
• Mid 18th century - evolution was “in the air”
• Mid 19th century - natural selection
• Mid 20th century - The Modern Synthesis
– genetics, biochemistry, embryology,
comparative anatomy, physiology, etc.
– mutation, neutral genetic change, genetic
drift, gene flow, catastrophe
Scientific Methods
• Science is objective and naturalistic
Scientific Methods
• Science is objective and naturalistic
– scientific explanations are based on
observations of nature that are available to
anyone
Scientific Methods
• Science is objective and naturalistic
– scientific explanations are based on
observations of nature that are available to
anyone
– scientific explanations assume that events in
nature occur without external intervention
Scientific Methods
• Scientific endeavors may be
– exploratory
Scientific Methods
• Scientific endeavors may be
– exploratory
– historical/“forensic”
Scientific Methods
• Scientific endeavors may be
– exploratory
– historical/“forensic”
– experimental
Scientific Methods
• Scientific investigation is hypothesis-driven
Scientific Methods
• Scientific investigation is hypothesis-driven
– Observations lead to questions
Scientific Methods
• Scientific investigation is hypothesis-driven
– Observations lead to questions
– Questions lead to hypotheses (+/- educated
guesses)
Scientific Methods
• Scientific investigation is hypothesis-driven
– Observations lead to questions
– Questions lead to hypotheses (+/- educated
guesses)
– Hypotheses lead to predictions
Scientific Methods
• Scientific investigation is hypothesis-driven
– Observations lead to questions
– Questions lead to hypotheses (+/- educated
guesses)
– Hypotheses lead to predictions
– Predictions are tested by collection and
analysis of data (natural, historical,
experimental)
Landmarks in the Evolution of Life
Landmarks in the Evolution of Life
• Life from non-life
Life
Began
Early
in
Earth’s
History
Figure 1.3
Landmarks in the Evolution of Life
• Life from non-life
• First cells
Landmarks in the Evolution of Life
• Life from non-life
• First cells
• Oxygenic photosynthesis
An oxygenic cyanobacterium
Figure 1.4
Life
Occurred
Without
Oxygen
for
13 Days
Figure 1.3
Landmarks in the Evolution of Life
•
•
•
•
Life from non-life
First cells
Oxygenic photosynthesis
Increased variability
Landmarks in the Evolution of Life
•
•
•
•
•
Life from non-life
First cells
Oxygenic photosynthesis
Increased variability
Eukaryotic cells
A compartmentalized eukaryotic cell
Figure 1.5
All Organisms
were
Prokaryotic
for
19 Days
Figure 1.3
Landmarks in the Evolution of Life
•
•
•
•
•
•
Life from non-life
First cells
Oxygenic photosynthesis
Increased variability
Eukaryotic cells
Multicellularity
All
Life
was
Unicellular for
23 Days
Figure 1.3
Landmarks in the Evolution of Life
•
•
•
•
•
•
•
Life from non-life
First cells
Oxygenic photosynthesis
Increased variability
Eukaryotic cells
Multicellularity
Invasion of Land
All
Life
was
Aquatic
for
27 Days
Figure 1.3
Landmarks in the Evolution of Life
•
•
•
•
•
•
•
•
Life from non-life
First cells
Oxygenic photosynthesis
Increased variability
Eukaryotic cells
Multicellularity
Invasion of Land
Human Influence
Recorded
Human
History Began
a Few Seconds
Ago
Figure 1.3