introduction: ap biology - r. wingerden eighth edition ... introduction: ap biology chapter 1 major...

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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

PowerPoint® Lecture Presentations for

BiologyEighth Edition

Neil Campbell and Jane Reece

Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp

Introduction: AP Biology

Chapter 1 Major Themes of AP Biology

• Biology consists of more than memorizingfactual details

• Unifying constructs in AP Biology:– Science as a Process– Evolution– Energy Transfer– Continuity and Change– Relationship of Structure to Function– Regulation– Interdependence in Nature– Science, Technology, and Society


Evolution, the Overarching Theme of Biology

• Evolution is the process of change that hastransformed life on Earth

• Biology is the scientific study of life

• Evolution accounts for the unity and diversity oflife

• “Nothing in biology makes sense except in thelight of evolution”—Theodosius Dobzhansky


Organizing the Diversity of Life

• Approximately 1.8 million species have beenidentified and named to date, and thousandsmore are identified each year

• Estimates of the total number of species thatactually exist range from 10 million to over 100million


Grouping Species: The Basic Idea

• Taxonomy is the branch of biology that namesand classifies species into groups of increasingbreadth

• Domains, followed by kingdoms, are thebroadest units of classification


Fig. 1-14Species Genus Family Order Class Phylum Kingdom Domain

Ursus americanus(American black bear)

Ursus

Ursidae

Carnivora

Mammalia

Chordata

Animalia

Eukarya

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The Three Domains of Life

• The three-domain system is currently used,and replaces the old five-kingdom system

• Domain Bacteria and domain Archaeacomprise the prokaryotes

• Domain Eukarya includes all eukaryoticorganisms:

– Single celled ~ Protists

– Multicellular ~ Plantae, Fungi, Animalia


Fig. 1-15(a) DOMAIN BACTERIA

(b) DOMAIN ARCHAEA

(c) DOMAIN EUKARYA

Protists

Kingdom Fungi

KingdomPlantae

Kingdom Animalia

Unity in the Diversity of Life

• A striking unity underlies the diversity of life; forexample:

– DNA is the universal genetic languagecommon to all organisms

– Unity is evident in many features of cellstructure


Charles Darwin and the Theory of NaturalSelection

• Fossils and other evidence document theevolution of life on Earth over billions of years


Fig. 1-17

• Charles Darwin published On the Origin ofSpecies by Means of Natural Selection in 1859

• Darwin made two main points:

– Species showed evidence of “descent withmodification” from common ancestors

– Natural selection is the mechanism behind“descent with modification”

• Darwin’s theory explained the duality of unityand diversity


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Fig. 1-18 Fig. 1-19

• Darwin observed that:

– Individuals in a population have traits that vary

– Many of these traits are heritable (passed fromparents to offspring)

– More offspring are produced than survive

– Competition is inevitable

– Species generally suit their environment


• Darwin inferred that:

– Individuals that are best suited to theirenvironment are more likely to survive andreproduce

– Over time, more individuals in a population willhave the advantageous traits

• In other words, the natural environment“selects” for beneficial traits


Fig. 1-20

Populationwith variedinherited traits.

Eliminationof individualswith certaintraits.

Reproductionof survivors.

Increasingfrequencyof traits thatenhancesurvival andreproductivesuccess.

4321

• Natural selection is often evident in adaptationsof organisms to their way of life andenvironment

• Bat wings are an example of adaptation

Video: Soaring HawkVideo: Soaring Hawk


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Fig. 1-21

The Tree of Life

• “Unity in diversity” arises from “descent withmodification”

– For example, the forelimb of the bat, human,horse and the whale flipper all share acommon skeletal architecture

• Fossils provide additional evidence ofanatomical unity from descent with modification


Concept 1.3: Scientists use two main forms ofinquiry in their study of nature

• The word Science is derived from Latin andmeans “to know”

• Inquiry is the search for information andexplanation

• There are two main types of scientific inquiry:discovery science and hypothesis-basedscience


Discovery Science

• Discovery science describes naturalstructures and processes

• This approach is based on observation and theanalysis of data


Types of Data

• Data are recorded observations or items ofinformation

• Data fall into two categories

– Qualitative, or descriptions rather thanmeasurements

– Quantitative, or recorded measurements,which are sometimes organized into tables andgraphs


Fig. 1-23

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Induction in Discovery Science

• Inductive reasoning draws conclusionsthrough the logical process of induction

• Repeat specific observations can lead toimportant generalizations

– For example, “the sun always rises in the east”


Hypothesis-Based Science

• Observations can lead us to ask questions andpropose hypothetical explanations calledhypotheses


The Role of Hypotheses in Inquiry

• A hypothesis is a tentative answer to a well-framed question

• A scientific hypothesis leads to predictions thatcan be tested by observation orexperimentation


• For example,

– Observation: Your flashlight doesn’t work

– Question: Why doesn’t your flashlight work?

– Hypothesis 1: The batteries are dead

– Hypothesis 2: The bulb is burnt out

• Both these hypotheses are testable


Fig. 1-24

Observations

Question

Hypothesis #1:Dead batteries

Hypothesis #2:Burnt-out bulb

Prediction:Replacing batterieswill fix problem

Prediction:Replacing bulbwill fix problem

Test prediction Test prediction

Test falsifies hypothesis Test does not falsify hypothesis

Fig. 1-24a

Observations

Question



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Fig. 1-24b

Test prediction



Test prediction

Prediction:Replacing batterieswill fix problem

Prediction:Replacing bulbwill fix problem

Test falsifies hypothesis Test does not falsify hypothesis

Deduction: The “If…Then” Logic of HypothesisBased Science

• Deductive reasoning uses general premisesto make specific predictions

• For example, if organisms are made of cells(premise 1), and humans are organisms(premise 2), then humans are composed ofcells (deductive prediction)


A Closer Look at Hypotheses in Scientific Inquiry

• A hypothesis must be testable and falsifiable

• Hypothesis-based science often makes use oftwo or more alternative hypotheses

• Failure to falsify a hypothesis does not provethat hypothesis

– For example, you replace your flashlight bulb,and it now works; this supports the hypothesisthat your bulb was burnt out, but does notprove it (perhaps the first bulb was insertedincorrectly)


The Myth of the Scientific Method

• The scientific method is an idealized process ofinquiry

• Hypothesis-based science is based on the“textbook” scientific method but rarely followsall the ordered steps

• Discovery science has made importantcontributions with very little dependence on theso-called scientific method


A Case Study in Scientific Inquiry: InvestigatingMimicry in Snake Populations

• Many poisonous species are brightly colored,which warns potential predators

• Mimics are harmless species that closelyresemble poisonous species

• Henry Bates hypothesized that this mimicryevolved in harmless species as an evolutionaryadaptation that reduces their chances of beingeaten


• This hypothesis was tested with the poisonouseastern coral snake and its mimic thenonpoisonous scarlet kingsnake

• Both species live in the Carolinas, but thekingsnake is also found in regions withoutpoisonous coral snakes

• If predators inherit an avoidance of the coralsnake’s coloration, then the colorful kingsnakewill be attacked less often in the regions wherecoral snakes are present


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Fig. 1-25

SouthCarolina

NorthCarolina

Key

Scarlet kingsnake (nonpoisonous)

Scarlet kingsnake (nonpoisonous)

Eastern coral snake(poisonous)

Range of scarletkingsnake onlyOverlapping ranges ofscarlet kingsnake andeastern coral snake

Field Experiments with Artificial Snakes

• To test this mimicry hypothesis, researchersmade hundreds of artificial snakes:

– An experimental group resembling kingsnakes

– A control group resembling plain brown snakes

• Equal numbers of both types were placed atfield sites, including areas without poisonouscoral snakes


Fig. 1-26

(a) Artificial kingsnake

(b) Brown artificial snake that has been attacked

Fig. 1-26a

(a) Artificial kingsnake

Fig. 1-26b

(b) Brown artificial snake that has been attacked

• After four weeks, the scientists retrieved theartificial snakes and counted bite or claw marks

• The data fit the predictions of the mimicryhypothesis: the ringed snakes were attackedless frequently in the geographic region wherecoral snakes were found


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Fig. 1-27

Artificialkingsnakes

Brownartificialsnakes

83% 84%

17% 16%

Coral snakesabsent

Coral snakespresent

Perc

ent o

f tot

al a

ttack

son

art

ifici

al s

nake

s

100

80

60

40

20

0

RESULTS Designing Controlled Experiments

• A controlled experiment compares an experimentalgroup (the artificial kingsnakes) with a control group(the artificial brown snakes)

• Ideally, only the variable of interest (the color patternof the artificial snakes) differs between the control andexperimental groups

• A controlled experiment means that control groups areused to cancel the effects of unwanted variables

• A controlled experiment does not mean that allunwanted variables are kept constant


Limitations of Science

• In science, observations and experimentalresults must be repeatable

• Science cannot support or falsify supernaturalexplanations, which are outside the bounds ofscience


Theories in Science

• In the context of science, a theory is:

– Broader in scope than a hypothesis

– General, and can lead to new testablehypotheses

– Supported by a large body of evidence incomparison to a hypothesis


Model Building in Science

• Models are representations of naturalphenomena and can take the form of:

– Diagrams

– Three-dimensional objects

– Computer programs

– Mathematical equations


Fig. 1-28Frombody

Fromlungs

Rightatrium

Leftatrium

Leftventricle

Rightventricle

To lungs To body

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The Culture of Science

• Most scientists work in teams, which ofteninclude graduate and undergraduate students

• Good communication is important in order toshare results through seminars, publications,and websites


Fig. 1-29

Science, Technology, and Society

• The goal of science is to understand naturalphenomena

• The goal of technology is to apply scientificknowledge for some specific purpose

• Science and technology are interdependent

• Biology is marked by “discoveries,” whiletechnology is marked by “inventions”


• The combination of science and technologyhas dramatic effects on society

– For example, the discovery of DNA by JamesWatson and Francis Crick allowed foradvances in DNA technology such as testingfor hereditary diseases

• Ethical issues can arise from new technology,but have as much to do with politics,economics, and cultural values as with scienceand technology


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