bsc 2010 suzanne butler 1271-9 (305)237-8118 [email protected]
TRANSCRIPT
TextbooksTextbooks
• Required textRequired textBiology, 6Biology, 6thth ed. Neil Campbell and J. ed. Neil Campbell and J.
Reese. 2002. Benjamin CummingsReese. 2002. Benjamin Cummings..
• Optional TextbookOptional TextbookChemistry for Biology Students, 7Chemistry for Biology Students, 7thth ed. by George ed. by George
SackheimSackheim
Introduction: Ten Themes Introduction: Ten Themes in the Study of Lifein the Study of Life
Chapter 1Chapter 1
Biology Biology
Scientific study of lifeScientific study of life
Lays the foundation Lays the foundation for asking basic questions about life for asking basic questions about life
and the natural worldand the natural world
Evolution of Biology As a Evolution of Biology As a ScienceScience
• Through the Middle AgesThrough the Middle Ages– Major scientific discoveries were made Major scientific discoveries were made
in early Egypt, Babylonia, and Greecein early Egypt, Babylonia, and Greece– Between 200 and 1200 AD there were Between 200 and 1200 AD there were
almost no important scientific advancesalmost no important scientific advances– No real distinction made between No real distinction made between
science and theologyscience and theology– Not much questioning of anythingNot much questioning of anything
Evolution of Biology As a Evolution of Biology As a ScienceScience
• Intellectual Reawakening in EuropeIntellectual Reawakening in Europe– Albertus Magnus and Thomas AquinasAlbertus Magnus and Thomas Aquinas
• Theologians and philosophers teaching in ParisTheologians and philosophers teaching in Paris
• Prepared the way for more independent development Prepared the way for more independent development of scienceof science
– Roger BaconRoger Bacon• Called for an end to unthinking acceptance of Called for an end to unthinking acceptance of
classical writings such as Aristotleclassical writings such as Aristotle
““Cease to be ruled by dogmas and authorities; look Cease to be ruled by dogmas and authorities; look
at the worldat the world.”.”
Evolution of Biology As a Evolution of Biology As a ScienceScience
• New Era in the Physical SciencesNew Era in the Physical Sciences– Copernicus and GalileoCopernicus and Galileo
• said the earth was not the center of the universesaid the earth was not the center of the universe
• Led to the conclusion that the earth can be Led to the conclusion that the earth can be understood in terms of universal lawsunderstood in terms of universal laws
– Isaac NewtonIsaac Newton• Discovery of the Laws of Gravitation Discovery of the Laws of Gravitation
• explanations in 1685 of the movements of planetsexplanations in 1685 of the movements of planets
• Caused a revolution in human thoughtCaused a revolution in human thought
• Moved physical science into new eraMoved physical science into new era
Evolution of Biology As a Evolution of Biology As a ScienceScience
• New Era in Biological SciencesNew Era in Biological Sciences– Did not begin until the middle of the Did not begin until the middle of the
nineteenth centurynineteenth century– Began when Pasteur finally disproved Began when Pasteur finally disproved
“spontaneous generation”“spontaneous generation”– Darwin’s work on evolution was the Darwin’s work on evolution was the
beginning of the same kind of revolution beginning of the same kind of revolution in biology that Newton’s began in in biology that Newton’s began in physicsphysics
Spontaneous GenerationSpontaneous Generation
• Prevailing scientific view for over 300 Prevailing scientific view for over 300 yearsyears
• Organisms are regularly generated Organisms are regularly generated from non living materials from non living materials – Put Garbage in the streetPut Garbage in the street
• Rats generate spontaneouslyRats generate spontaneously
– Hang meat in open stallsHang meat in open stalls• Maggots appearMaggots appear
– Put broth on the window sill to coolPut broth on the window sill to cool• Bacteria growBacteria grow
DisprovingSpontaneous DisprovingSpontaneous GenerationGeneration
• Francesco Redi Francesco Redi – performed an experiment to check performed an experiment to check
whether maggots really came from whether maggots really came from decaying meatdecaying meat
– placed meat in a number of jars and placed meat in a number of jars and covering half of them with fine gauze covering half of them with fine gauze while leaving the others uncoveredwhile leaving the others uncovered
– Maggots developed only on the meat in Maggots developed only on the meat in the uncovered jars the uncovered jars
Argument in Support of Argument in Support of Spontaneous GenerationSpontaneous Generation
• the belief in spontaneous generation remained strong, and the belief in spontaneous generation remained strong, and even Redi continued to believe it occurred under some even Redi continued to believe it occurred under some circumstancescircumstances
• invention of the microscope only served to enhance this beliefinvention of the microscope only served to enhance this belief – a whole new world of organisms that appeared to arise a whole new world of organisms that appeared to arise
spontaneously spontaneously
• John Needham John Needham – knew that boiling killed microorganismsknew that boiling killed microorganisms – boiled chicken broth, put it into a flask, sealed it, andboiled chicken broth, put it into a flask, sealed it, and
- sure enough, microorganisms grew - sure enough, microorganisms grew
– claimed victory for spontaneous generationclaimed victory for spontaneous generation
Disproving Spontaneous Disproving Spontaneous GenerationGeneration
• Lazzaro SpallanzaniLazzaro Spallanzani – almost one hundred years after Redi’s experiments modified almost one hundred years after Redi’s experiments modified
Needham’s experimentNeedham’s experiment
Argument Supporting Argument Supporting Spontaneous GenerationSpontaneous Generation
• Spallanzani had only proven that Spallanzani had only proven that spontaneous generation could not spontaneous generation could not occur without air. occur without air.
DisprovingSpontaneous DisprovingSpontaneous GenerationGeneration
• Louis PasteurLouis Pasteur– Boiled nutrient mixture in flask with long s-Boiled nutrient mixture in flask with long s-
shaped necksshaped necks– Almost all flasks treated this way remained Almost all flasks treated this way remained
free of bacterial growth as long as the neck free of bacterial growth as long as the neck was unbrokenwas unbroken
– When Pasteur tilted the flask so that the broth When Pasteur tilted the flask so that the broth reached the lowest point in the neck, where reached the lowest point in the neck, where any airborne particles would have settled, the any airborne particles would have settled, the broth rapidly became cloudy with life broth rapidly became cloudy with life
– Concluded that microorganisms were brought Concluded that microorganisms were brought into flask on dust particles rather than into flask on dust particles rather than generated from the nutrient mixturegenerated from the nutrient mixture
Evolution of Biology As a Evolution of Biology As a ScienceScience
• New Era in Biological SciencesNew Era in Biological Sciences– Did not begin until the middle of the Did not begin until the middle of the
nineteenth centurynineteenth century– Began when Pasteur finally disproved Began when Pasteur finally disproved
“spontaneous generation”“spontaneous generation”– Darwin’s work on evolution was the Darwin’s work on evolution was the
beginning of the same kind of revolution beginning of the same kind of revolution in biology that Newton’s began in in biology that Newton’s began in physicsphysics
The Evolution of EvolutionThe Evolution of Evolution
– CuvierCuvier• CatastrophismCatastrophism
– One time creationOne time creation– Successive catastrophes caused some to become Successive catastrophes caused some to become
extinct and others to fluorishextinct and others to fluorish
– LamarckLamarck• Proposed inheritance of acquired characteristicsProposed inheritance of acquired characteristics
– LyellLyell• Princilpes of Geology, 1830Princilpes of Geology, 1830• Proposed that geological forces Proposed that geological forces still operating still operating could could
account for the changes that were seen in the earth’s account for the changes that were seen in the earth’s surfacesurface
• Earth not in final form at creation, but steadily Earth not in final form at creation, but steadily undergoing changeundergoing change
Charles DarwinCharles Darwin
• At 8 years old he was intrigued with At 8 years old he was intrigued with the natural world.the natural world.
• He studied medicine but could not He studied medicine but could not stomach surgery stomach surgery
• He then studied to be a clergyman, He then studied to be a clergyman, but spent his time with scientists but spent his time with scientists while at Cambridgewhile at Cambridge
Darwin’s VoyageDarwin’s Voyage
• At age 22, Charles Darwin began a five-year, At age 22, Charles Darwin began a five-year, round-the-world voyage aboard the round-the-world voyage aboard the Beagle Beagle
• In his role as ship’s naturalist he collected In his role as ship’s naturalist he collected and examined the species that inhabited the and examined the species that inhabited the regions the ship visitedregions the ship visited
Voyage of the BeagleVoyage of the Beagle
EQUATOR
GalapagosIslands
GalapagosGalapagosIslandsIslands
Isabela
Darwin
Wolf
Pinta
Marchena Genovesa
Fernandia
SantiagoBartolomé
RabidaPinzon
SeymourBaltra
Santa Cruz
Santa Fe
Tortuga
Española
San Cristobal
Floreana
Volcanic islands far off coast of Ecuador
All inhabitants are descended from species that arrived on islands from elsewhere
Darwin’s ObservationsDarwin’s Observations
• In Argentina, Darwin observed fossils In Argentina, Darwin observed fossils of extinct glyptodontsof extinct glyptodonts
• Animals resembled living armadillosAnimals resembled living armadillos
• In the Galapalos Islands he saw In the Galapalos Islands he saw strange iguanas, turtles, and strange iguanas, turtles, and mocking birds that varied from one mocking birds that varied from one island to anotherisland to another
Galapagos FinchesGalapagos Finches
• Darwin observed finches with a Darwin observed finches with a variety of lifestyles and body formsvariety of lifestyles and body forms
• On his return he learned that there On his return he learned that there were 13 specieswere 13 species
• He attempted to correlate variations He attempted to correlate variations in their traits with environmental in their traits with environmental challengeschallenges
Diversification of finches on the Galápagos IslandsDiversification of finches on the Galápagos Islands
Darwin Begins to Darwin Begins to UnderstandUnderstand
• The Galapagos finches were related to an The Galapagos finches were related to an ancestral species that could be found on ancestral species that could be found on the mainland of SA hundreds of miles to the mainland of SA hundreds of miles to the eastthe east
• Members of that ancestral species had Members of that ancestral species had come to the Galapagos by air then fanned come to the Galapagos by air then fanned out to separate islands out to separate islands
• They had diverged over time into separate They had diverged over time into separate speciesspecies
• Still had no mechanism for driving this Still had no mechanism for driving this “descent with modification”“descent with modification”
Malthus - Struggle to Malthus - Struggle to SurviveSurvive• Thomas Malthus, a clergyman and Thomas Malthus, a clergyman and
economist, wrote essay that Darwin economist, wrote essay that Darwin read 2 years after his return to Englandread 2 years after his return to England
• Argued that as population size Argued that as population size increases, resources dwindle, the increases, resources dwindle, the struggle to live intensifies and conflict struggle to live intensifies and conflict increasesincreases
Darwin’s TheoryDarwin’s Theory
• Rejects the notion that living creatures are Rejects the notion that living creatures are immutable products of a sudden creation.immutable products of a sudden creation.
• A population can change over time when A population can change over time when individuals differ in one or more heritable individuals differ in one or more heritable traits that are responsible for differences in traits that are responsible for differences in the ability to survive and reproducethe ability to survive and reproduce
Figure 1.15 Natural selectionFigure 1.15 Natural selection
Alfred WallaceAlfred Wallace
• Naturalist who arrived at the same Naturalist who arrived at the same
conclusions Darwin didconclusions Darwin did
• Wrote to Darwin describing his viewsWrote to Darwin describing his views
• Prompted Darwin to finally present Prompted Darwin to finally present
his ideas in a formal paper his ideas in a formal paper
On the Origin of SpeciesOn the Origin of Species
• Darwin’s bookDarwin’s book
• Published in 1859Published in 1859
• Laid out in great detail his Laid out in great detail his
evidence in support of the theory evidence in support of the theory
of evolution by natural selectionof evolution by natural selection
Two Parts of Darwin’s Two Parts of Darwin’s TheoryTheory• Descent with modificationDescent with modification
– Change is the rule rather than the exceptionChange is the rule rather than the exception– Organisms living today have descended by gradual Organisms living today have descended by gradual
changes from ancient ancestors quite unlike themselveschanges from ancient ancestors quite unlike themselves
• Natural selection determines the course of the Natural selection determines the course of the changechange– It is a completely mechanistic process without conscious It is a completely mechanistic process without conscious
purpose or designpurpose or design– individuals differ in one or more heritable traits that are individuals differ in one or more heritable traits that are
responsible for differences in the ability to survive and responsible for differences in the ability to survive and reproducereproduce
Populations EvolvePopulations Evolve
• Biological evolution does not Biological evolution does not change individualschange individuals
• It changes a populationIt changes a population
• Traits in a population vary among Traits in a population vary among individualsindividuals
• Evolution is change in frequency Evolution is change in frequency of traitsof traits
Some properties of lifeSome properties of life
How Do We Know If It is Alive?How Do We Know If It is Alive?
• MetabolismMetabolism– Taking in and digesting foodTaking in and digesting food– Assimilating digested foodAssimilating digested food– RespirationRespiration– ExcretionExcretion
• Non-living things do not derive energy by Non-living things do not derive energy by taking in or transforming foreign matter.taking in or transforming foreign matter.
Energy utilizationEnergy utilization
How Do We Know If It is Alive?How Do We Know If It is Alive?
• Growth and DevelopmentGrowth and Development– Organisms develop new parts between Organisms develop new parts between
or within older partsor within older parts
• Non-living things can grow only by Non-living things can grow only by addition of material to the outside.addition of material to the outside.
Growth and developmentGrowth and development
How Do We Know If It is Alive?How Do We Know If It is Alive?
• IrritabilityIrritability– Response to environmental stimuliResponse to environmental stimuli
• Many formsMany forms
• May not be proportional to stimulusMay not be proportional to stimulus
• Organism not usually permanently altered by the Organism not usually permanently altered by the stimulusstimulus
• Non-living things may react to stimuliNon-living things may react to stimuli – Always a quantitative relationship between the Always a quantitative relationship between the
stimulus and the effectstimulus and the effect
How Do We Know If It is Alive?How Do We Know If It is Alive?
• ReproductionReproduction– Each kind of living thing reproduces itself Each kind of living thing reproduces itself
in kindin kind– Information needed to develop and Information needed to develop and
reproduce is segregated within the reproduce is segregated within the organismorganism
– Information needed to develop and Information needed to develop and reproduce is passed to offspringreproduce is passed to offspring
• Non-living things do not reproduce Non-living things do not reproduce
ReproductionReproduction
How Do We Know If It is Alive?How Do We Know If It is Alive?
• Evolution and AdaptationEvolution and Adaptation– Groups of organisms change over timeGroups of organisms change over time– Changes make organisms more able to Changes make organisms more able to
live in the particular local environmentlive in the particular local environment
• Non-living things do not change nor Non-living things do not change nor adapt to the environmentadapt to the environment
How Do We Know If It is Alive?How Do We Know If It is Alive?
• OrderOrder– All organisms are highly organized All organisms are highly organized – Maintain that organization by expending Maintain that organization by expending
energyenergy– Each type usually has definite form and Each type usually has definite form and
shapeshape– All organisms are composed of cellsAll organisms are composed of cells
• Non-living things do not maintain their Non-living things do not maintain their organization by expending energyorganization by expending energy
OrderOrder
Unity of LifeUnity of Life
All organisms: All organisms:
– Are composed of the same substancesAre composed of the same substances
– Engage in metabolismEngage in metabolism
– Sense and respond to the environmentSense and respond to the environment
– Have the capacity to reproduce based Have the capacity to reproduce based
on instructions in DNAon instructions in DNA
Figure 1.5 The genetic material: DNAFigure 1.5 The genetic material: DNA
Diversity of LifeDiversity of Life
• Millions of living speciesMillions of living species
• Additional millions of species now Additional millions of species now
extinctextinct
• Classification scheme attempts to Classification scheme attempts to
organize this diversityorganize this diversity
Five KingdomsFive Kingdoms
Classifying lifeClassifying life
Structure and FunctionStructure and Function
• Correlated at all levels of lifeCorrelated at all levels of life• A bird’s shape and it’s skeletonA bird’s shape and it’s skeleton
– Make flight possibleMake flight possible• Aerodynamic shape of wingAerodynamic shape of wing• Honeycombed construction of boneHoneycombed construction of bone
• A cell’s form fits its specialized functionA cell’s form fits its specialized function– Nerve cells have long extensions that transmit Nerve cells have long extensions that transmit
signalssignals
• At the sub-cellular levelAt the sub-cellular level– Inner membrane of mitochondrion is folded to Inner membrane of mitochondrion is folded to
provide more surface areaprovide more surface area
Form fits functionForm fits function
Scientific MethodScientific Method
• Observe phenomenonObserve phenomenon
• Develop hypotheses Develop hypotheses
• Make predictionsMake predictions
• Devise test of predictionsDevise test of predictions
• Carry out test and analyze Carry out test and analyze
results results
Careful observation and measurement provide the raw Careful observation and measurement provide the raw data for sciencedata for science
Inductive LogicInductive Logic
• Using observations and facts to arrive at Using observations and facts to arrive at
generalizations or hypothesesgeneralizations or hypotheses
• ObservationObservation: Eagles, swallows, and : Eagles, swallows, and
robins have feathersrobins have feathers
• HypothesisHypothesis: All birds have feathers: All birds have feathers
Deductive LogicDeductive Logic
• Drawing a specific conclusion based Drawing a specific conclusion based
on a generalization on a generalization
– GeneralizationGeneralization - Birds have feathers - Birds have feathers
– ExampleExample - Eagles are birds - Eagles are birds
– ConclusionConclusion - Eagles have feathers - Eagles have feathers
Idealized version of the scientific methodIdealized version of the scientific method
Role of ExperimentsRole of Experiments
• Procedures used to study a Procedures used to study a phenomenon under known conditions phenomenon under known conditions
• Allows you to predict what will Allows you to predict what will happen if a hypothesis is not wronghappen if a hypothesis is not wrong
• Can never prove a hypothesis 100% Can never prove a hypothesis 100% correctcorrect
David Reznick conducting field experiments on guppy evolution in David Reznick conducting field experiments on guppy evolution in TrinidadTrinidad
Controlled experiments to test the hypothesis that selective Controlled experiments to test the hypothesis that selective predation affects the evolution of guppy populationspredation affects the evolution of guppy populations
Experimental Design Experimental Design
• Control group Control group – A standard for comparisonA standard for comparison
– Identical to experimental group except for Identical to experimental group except for
variable being studiedvariable being studied
• Sampling errorSampling error– Non-representative sample skews resultsNon-representative sample skews results
– Minimize by using large samplesMinimize by using large samples
Fig. 1.10, p. 12
CONTROL GROUPThe variable being
tested is absent
EXPERIMENTAL GROUPThe variable beingtested is present
Draw samples from some aspect of nature
Compile results Compile results
Compare and analyze the test results
Report on experimental design, test results, and conclusions drawn from results
Scientific TheoryScientific Theory
• An hypothesis that has been tested An hypothesis that has been tested for its predictive power many times for its predictive power many times and has not yet been found incorrectand has not yet been found incorrect
• Has wide-ranging explanatory powerHas wide-ranging explanatory power– Darwin’s Theory of Evolution by Natural Darwin’s Theory of Evolution by Natural
SelectionSelection
Limits of ScienceLimits of Science
• Scientific approach cannot provide Scientific approach cannot provide answers to subjective questionsanswers to subjective questions
• Cannot provide moral, aesthetic, or Cannot provide moral, aesthetic, or philosophical standardsphilosophical standards
Science and the Science and the SupernaturalSupernatural
• Science has run up against religious Science has run up against religious
belief systemsbelief systems
– Copernicus suggested that sun, not the Copernicus suggested that sun, not the
Earth, was center of universeEarth, was center of universe
– Darwin suggested that life was shaped Darwin suggested that life was shaped
by evolution, not a single creation eventby evolution, not a single creation event
Asking QuestionsAsking Questions
• Scientists still ask questions that Scientists still ask questions that
challenge widely held beliefschallenge widely held beliefs
• The external world, not internal The external world, not internal
conviction, is the testing ground for conviction, is the testing ground for
scientific beliefsscientific beliefs
Review of Ten Unifying Themes in BiologyReview of Ten Unifying Themes in Biology
Review of Ten Unifying Themes in Biology (Review of Ten Unifying Themes in Biology (continuedcontinued))