1. Repressor protein blocking β-galactosidase
gene transcription in the absence of lactose
(top) and lactose removing the repressor to
allow for transcription (bottom)
Evolution and Diversity
Article 1- Intelligent design:http://www.discovery.org/a/2640
Aspect: Intricate complexity of cells
Part A:
Intelligentdesignactivistsclaimthatthe structure andfunctionof organisms,of whichthere are
approximately8.7milliondifferenttypesinthe world,are sointricate andcomplex thattheymust
have beencreatedbya supernatural ‘intelligentdesigner’ (Isaak,2005).The detail thatisexhibited
inmicroscopiccells andthe way inwhichthe structure evenwithinthese minisculecellsreflecttheir
functioninfersthatlife musthave beendesignedasopposedtobeingthe resultof evolutionary
processes (Isaak,2005). Justas a buildingisclearlydesignedandconstructedbyman,withdifferent
structureswithin,suchasdoors,windows,roofs,etceterathatreflecttheirpurpose,soare cells
made withsuch an aspectof design (Isaak,2005). Inside acell,organelles are heldinthe cytoplasm
by a phospholipidbilayer(the outer membrane),whichholds‘productionlines’ togethersotheycan
performtheirtask,suchas buildingproteins,with more energyefficiency thanif theywere free-
floating(Goldberg,2007). Thisreflectsdesignaswithoutthismembrane,cellswoulduse upmuch
more energy so the organism would need to have a higher energy intake to sustain its cells (Stanford,
2011). The exactamountof energyusedbycellsisspecifically designed becauseif organismsrequire
more energythroughconsumptionbutstill have the same reproductiverate then the complex food
webwouldfall outof balance as organismsare decreasingata fasterrate thanare beingproduced
(Stanford,2011).
Such intricate designwas evidentinanexperiment of the β-galactosidasegene whichoccursin
Escherichia coli bacteriaand can be regulateddependingonwhetherlactose ispresent (Spenceley,
2007). Lactose issplitintoglucose andgalactose bythe β-galactosidase enzyme sothe more lactose
added;consequentlymore of thisenzyme isproduced sothe bacteriumcanutilizethe available
lactose (Spenceley,2007). Asbacteriagenerallydonotencounterlactose, β-galactosidase isnot
normallyproducedbecause of the repressorproteinthat
regulatesthe gene production andtherefore savesalotof
energythatwouldotherwise be wastedonproducingthe
enzyme thatcannotbe usedforany otherpurpose
(Spenceley,2007).Thisagain reflectsthe purposefuldesign
incorporatedintothe microscopicfunctionswithinacell
because of the energyconservationthatallowsthe foodweb
to stay ina delicate balance.Inthe absence of lactose,the
repressorproteinattachesitself tothe bacteria’sDNA and
therefore blocksmRNA synthesisof the β-galactosidase gene
so itcannot undergotranscriptionbut whenlactose is
available,itbindstothisrepressorprotein,forcingittobe
released sotranscriptioncanoccur(Spenceley,2007).The
experimentrevealedthat around6% of all the proteinsbeing
producedwithin10 minutesof addinglactose were β-galactosidaseandonce all of the lactose was
used,the productionof β-galactosidaseceased(Spenceley,2007).
No lactose
Lactose
2. In the chosenarticle,JosephKuhn,adoctorat BaylorUniversityMedical Center, quotesMichael
Behe’sfamousnovel, Darwin’sBlackBox, toexplainthe aspectof cell complexity: "irreducible
complexitysuggeststhatall elementsof asystemmustbe presentsimultaneouslyratherthan
evolve throughastepwise,sequential improvement,astheorizedbyDarwinianevolution”(Kuhn,
2012). Because thisgene regulationprocess issointricate,one smallchange wouldcompromise the
whole procedure,suchasif the shape of the repressorproteinchanged due toevolutionary
processes,whichwouldinhibitthe protein’s abilitytobindtothe DNA strand as all proteinshave a
specificstructure fortheirfunction (Universityof Arizona,2004).Proteinsare made up of a
sequence of aminoacidsand bondingwithinthispolypeptide chaincausesittofoldintoa particular
shape and experimental methodology hasrevealedthateachaminoacidisessential tothe protein’s
purpose (Alberts,2013). Fromthisevidence some assume thatthisintricacysupportsintelligent
design as such irreducibly complex systems could not have come about by chance (Alberts, 2013). Dr.
Kuhnstatesinthe online article, "The factthat these irreduciblycomplex systems are specifically
codedthroughDNA adds anotherlayerof complexity" (Kuhn,2012).As a medicinal practitionerhe
proposesthatmanysystemswithinthe humanbody,suchasbalance,vision,the immunesystem
and more,are irreduciblycomplex fromtheircellularstructurestoorgansto whole systems(Kuhn,
2012).
However,acommonargumentagainstthe ideaof cell complexity,specificallyof the eye,being
evidence of intelligentdesignisthatan organismwhichhas 50% of the eyesightof ahumanis still
betteroff thanif it had none (Pitman,2008). Many species withfarworse eye sightmanage to
survive,forexample; flatworms,whichcanmerelysense the directionof light,jellyfish,whichcan
onlydetectmovement, polychaete worms,whichcan onlysense the difference betweenlightand
dark and manymore (Pitman,2008). These organismsmaynothave beenintelligentlydesignedto
have this lack of visionbutevolutionaryprocessesmayhave causedthistrait,whichdidnotresultin
the extinctionof these speciesbecause theylearnedtoadapt (Pitman,2008).
Anotherflawof the intelligentdesigntheoryisfound inthe argumentthatcellsare the productof
designandcreationsimilartoman-made structures (Ragan,2000). Evolutionaryproponentsargue
that non-livingstructures,suchasbuildings,cannotreproduce orundergomutation sotherefore do
not have the opportunityassuchto be formedthroughevolutionaryprocesses (Ragan,2000). This
comparisonmaybe a popularargumenttosupportthe intelligentdesigntheorybecause itissimple
to understandbutnonethelessitcannotbe provenbythe scientificmethod,whichconsistsof
techniques,suchasmeasurement,systematicobservation,experimentandthe testingof
hypotheses.
3. The genotype for green beetles has a
poor fitness level relative to brown
beetles so the trait becomes less
prevalent/ non-existent
Phalacrocorax pelagicus
(Pelagic Cormorant)
Article 2- Evolution: http://www.newscientist.com/article/dn9953-instant-expert-evolution.html
Aspect: Evolutionary fitness
Part A:
Evolutionaryfitnessreferstothe capabilityof a genotype toproduce offspring,whichsurvive,in
relationtothe abilityof othergenotypestodoso (Orr, 2009). Therefore genotype fitnessisnot
measuredina specificunitbutiscomparedtothe successrate of othergenotypestosurvive,finda
mate and reproduce ina cyclicfashion,whichdependsonthe organisms’environment (Orr,2009).
Environmental factors,suchastemperature andpHhave a differentdegreeof effectonthe
reproductionand survival rate of differentorganismsdepending on
theiroptimumrange forthese factorsand their viability (King,2006).
Natural selection isanongoingprocessthatisa keymechanismof
evolution inwhich certaintraitsinapopulation become eithermore or
lessprevalentbecauseof the differentorganisms’ fitness(Orr,2009). If
the fitnessof anorganismispoor, whichresultsindramatically
decliningnumbersof offspring,the particulargenotype thatiscausing
the poor fitnesslevel will eventually be bredout;usually becausethe
organisms can’twithstand theirenvironmentorare prone to predation
(Orr,2009).
In the article chosen,JohnPickrellexplainsthat the evolutionaryfitness
of an organismaffectsitsfate inthe processof natural selection
because if all organismswithinapopulationwere tobe survivingon
limitedresources,some wouldhave little,
inheritabletraitsthatallow themahigher
chance of survival orreproductionthan
those withoutthemandso these advantageoustraitsbecome the new
normal (Pickrell,2006). Thisrelatestothe popularbelief among
evolutioniststhatpenguinsare nolongerable toflydue totheironce flight-
adaptedwings thatwere notof much use to themintheirenvironment
(Handwerk,2013). Theirwingshave become more ideal forswimmingand
have losttheirabilityto gainflightanditis believedthatthe lastpenguin
ancestorthat was able toflyisthe Phalacrocorax pelagicus,whichusesits
feettopropel itself throughthe water (Handwerk,2013).The penguins’wingevolutionhasallowed
themto dive more efficientlyandthus searchforfoodat depth,whichisseeninthe modern
emperorpenguinsthatcanquickly dive to450 metresdeepand holdtheirbreathforover20
minutes (Handwerk,2013). Thistheoryisevidencedthroughthe explorationof energycostsinbirds
that can dive and flyinwhichguillemots were foundtobe the mostefficientatdivingfora flying
birdbut penguins’divingability wasstillbetter(Handwerk,2013).Flighthasbecome more energy
expensive topenguinsthananyotherflyingbird orvertebrate due tothe gradual decrease of wing
size andthe thickeningof theirbones,whichmay now be helpfulfordivingastheyare thusless
buoyant(Handwerk,2013). Because the abilitytodive andswimhasbeenmore beneficial to
penguinsthanflight,the genotype forlarger,flight-adaptedwingshasbeenbredoutof the penguin
4. speciesbecause the genotype fortheircurrentwingstructure hadahigherdegree of fitness (Orr,
2009).
Thoughgradual changeshave beennoticedwithinspeciesasadaptationhasallowedforthe lessfit
genotypestobecome lessprevalent,there isnoevidence thatthese smallchangeshave caused
evolutionfromone commonancestor. A famedargumentthatisusedtosupportthe theoryof
evolutionaryfitnessisstemmedfromthe detailedstudyof the English pepperedmoth overthe last
twohundredyears (Ragan,2000). The majorityof pepperedmoths studiedhadlightcoloured wings,
whichallowedthemtocamouflage intotheirenvironmentbutduring England’sIndustrial
Revolution,muchof these mothshabitatswere destroyedorblackenedby sootsothe moths
became more preyedupon (Ragan,2000). As darkermothswere able to camouflage intothe new
surroundingsthey became more dominantastheirphenotypeincreasedtheirfitness andasthe
environmentbegantobe reestablished,the light-colouredmothsagainbecame more prevalent
(Ragan,2000). Similarly,insectpopulations canbecome more resistanttoinsecticidesandbacteria
to antibiotics asthe more robustorganismswithinthese populations are able tobreedwhilethose
more susceptible become illordie butall of these changesare merelyobserved microevolution
(Morris,1996). A conference washeldin1980 inwhich approximately 150 of the leading
evolutionary advocatesinthe world discussedmacroevolutionandconsideredwhetheritcanbe
deducedfromthe mechanismsof microevolution andthe verdictwasthatitcannot (Morris,1996).
JohnPickrell statesinthe article thatnatural selection,asa resultof varyingevolutionaryfitness,
“worksto create a populationthatis highlysuited toitsenvironment,andcanadapt to changes”
(Pickrell,2006). Thoughadaptationandmicroevolutionare supportedbyscientificstudies,there is
no evidence toprove thatnatural selectionhas causedthe creationof new species (Isaak,2005).
5. Part B:
IntelligentDesignsupportersbelieve thattheirtheoryof the universe,alongwithall livingthings,
beingthe resultof an intelligentcause ratherthanan uncertainprocess,issupportedbyscientific
evidence ratherthanmerelybeinga teleological argument.Manyscientistsregardthe theoryof
IntelligentDesigntobe a pseudoscience becauseit isbelief thatispresentedas scientific,butcannot
be provenby scientificmethodologyanditlackssupportingevidence soitthereforeitdoesnothave
scientificstatus or plausibility.Thoughthe intricacy of the processescontinuallyoccurringwithin
cellsmayinferthattheyhave beendesigned byanintelligentbeing insteadof happeningbychance,
there isno scientificevidence toprove it.The systemswithinthe humanbodyare evidently
extremelycomplex butitisuncertainwhetherornottheyare irreduciblyso.Microscopicprocesses
withincellscanandhave beenstudiedformanyyearsandit isevidentthatthe specificityof DNA
sequences,organelle shapesandsoon are all vitallyimportanttothe overall functionof cells,organs
and systems.However,fromthese studiesitcannotbe undeniablydeducedwhere,how orwhythe
originsof life began.
Proponentsforthe theoryof evolution generallyregardIntelligentDesigntobe a pseudoscience,
however,theirbelief that all livingorganismsoriginate fromone commonancestorthroughthe
processof natural selection alsolacksscientificevidence. The variationin genotypefitnessasa
resultof the organisms’ environmentcan cause slightchangesinapopulation,asseeninthe
example of the pepperedmoth,butthis canmerelyprove microevolution.The small changesthat
occur are not evidence thatall organismsare descendantsof the same ancestorbutevolutionists
assume thatthe observed ‘horizontal’ microevolutionarychangesleadtolarge,
‘vertical’macroevolutionarychanges.The factthatDarwin’stheoryof evolutionhas notbeen
provenshowsthatit isjustas much a philosophical opinionasthe creationismtheory.Scientific
researchcan suggestpossible eventsthattookplace inthe past throughanalysisandcomparisonsof
life today,butscience hasnotproventhe existenceof acommonancestorthat all life isbelievedto
have originatedfrom approximately3.8billionyearsago.
Neitherof these theories hasbeen completely scientificallyprovenbecause if theyhadbeenthere
wouldbe noneed forsuch an extreme philosophical debate. The aspects of boththeoriesthatwere
chosenhave some scientificsupportbutassumptionsneedtobe drawnonfor one to conclude that
the theoryisscientificallyjustified.Forexample;thoughthe processes inacell,suchas gene
regulation,reveal great complexityandsmall changescouldpotentiallyhave alarge-scale effect,
such as throwingthe foodweboutof proportion,itcan onlybe assumedthatit wasall designedand
createdby an intelligentbeing.Asforthe evolutiontheory, genotypefitnessisascientifically
supportedtrait,whichcancause microevolutionwithinapopulationbut thisphenomenahasmerely
beenextrapolatedtoproduce the ideaof macroevolutionbutitalsolacksscientificvalidity.
Althoughthese theorieshave notyetbeenunquestionably proven,science isacontinually
developingfield inwhichmany ideasare constantlybeing raised,clarifiedorrejectedsoneitherone
shouldbe mandatedfromcurriculumbyeducationpolicies until strongerevidence isdiscovered
againsteitherone.Manyscientistsandmedical practitionershave differentbeliefsastowhichis the
more scientifictheorybut toleadthe wayfor scientificdebate andpossible discoveriesinthe future,
the studentsof todayshouldbe taughtthe scientificaspectsof boththeories.
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