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

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

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

Static Creation in the Modern State

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young Earth

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young EarthAncient Earth

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young EarthAncient Earth Recent Origin of Life

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young EarthAncient Earth Recent Origin of LifeAncient Origin of Life

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young EarthAncient Earth Recent Origin of LifeAncient Origin of Life Discrete Species

Dueling Paradigms Static Creation in vs.Evolution from a the Modern StateLess-complex State Young EarthAncient Earth Recent Origin of LifeAncient Origin of Life Discrete SpeciesIntergrading Species

The Puzzle of Nature

SimilaritiesDifferences

The Puzzle of Nature SimilaritiesDifferences DNA is universal

All Organisms Share DNA Landmarks Figure 1.8

The Puzzle of Nature SimilaritiesDifferences DNA is universalGenomes Differ

The Puzzle of Nature SimilaritiesDifferences DNA is universalGenomes Differ Eukaryotic metabolism

The Puzzle of Nature SimilaritiesDifferences DNA is universalGenomes Differ EukaryoticProkaryotic metabolism

The Puzzle of Nature SimilaritiesDifferences DNA is universalGenomes Differ EukaryoticProkaryotic metabolism Structural homologies

Vertebrate Forelimb Homologies Figure 1.2

The Puzzle of Nature SimilaritiesDifferences DNA is universalGenomes differ EukaryoticProkaryotic metabolism Structural Functional Homologiesadaptations

Functional Adaptations Figure 1.7

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 ( ) The Temple of Nature

The “Evolution” of Evolution Count George-Louis Leclerc de Buffon ( )  Perhaps structural similarities are due to descent from a common ancestor with similar characteristics

The “Evolution” of Evolution Count George-Louis Leclerc de Buffon ( )  Perhaps structural similarities are due to descent from a common ancestor with similar characteristics Jean-Baptiste de Lamarck ( )  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 18 th century - evolution was “in the air”

The “Evolution” of Evolution Mid 18 th century - evolution was “in the air” Mid 19 th century - natural selection

The “Evolution” of Evolution Mid 18 th century - evolution was “in the air” Mid 19 th century - natural selection Mid 20 th century - The Modern Synthesis

The “Evolution” of Evolution Mid 18 th century - evolution was “in the air” Mid 19 th century - natural selection Mid 20 th century - The Modern Synthesis –genetics, biochemistry, embryology, comparative anatomy, physiology, etc.

The “Evolution” of Evolution Mid 18 th century - evolution was “in the air” Mid 19 th century - natural selection Mid 20 th 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

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