IntroductiontoBioinformaticsonlinecourse:IBT_2016
Practicalassignment#1
Moduletopic:Evolution&Phylogenetics
Contactsessiontitle:historicalperspective,mechanismsofmolecularevolutionand
speciation
Trainer:JBDomelevoEntfellner,JKayondo
Participant:<writeyournamehere>
Date:Wed.28September2016
Darwin’sfinchesoftheGalápagosIslands
Introduction
InthePacificOcean,approximately1,000kmwestofEcuador’scoastline,liesthevolcanic
archipelagooftheGalápagosIslands.DuringhislongjourneyontheHMSBeagle,Charles
Darwinstoppedontheseislandstomakeobservationspertaoningtothegeologyofthe
islands,butalsotocapturefloraandfaunaspecimen.Sincethen,thefinches(smallbirds,10
to20cmlong)oftheseislandshavebecomeaclassicofevolution.
Toolsusedinthissession
UsethefilesyouwillfindonlineontheIBTwebsite:
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•
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mapoftheGalápagosIslands
imagesoffinches
resultsbyLack(1947)onthedistributiononbeakdepthsonvariousislands
Task1:Predictingthedistributionoffinchesindifferenthabitats
Task1:instructions
Darwinobservedthateachoftheislandshadsimilartypesoffinches,iguanasandtortoises,
butthateachwasdifferenttomakethemostoflocalconditions.Drawingfromthe
informationgivenonthemapoftheGalápagosandonthedescriptionofthevarious
finches,tryandpredictthedistributionofthefinchesonthevariousislands(writeacrossin
therelevantcellswhereveryoubelieveagivenfinchmaybepresentonagivenisland).
IntroductiontoBioinformaticsonlinecourse:IBT_2016
SantaCruz
Plaza
SantaFe
Espanola
Florreana
Isabela
Fernandin
a
Genovesa
LargeGround
Finch
CactusFinch
SmallTreeFinch
SmallGroundFinch VegetarianFinch
LargeTreeFinch
WarblerFinch
Task1:participant’sanswer
Task2:Physicalcharacteristicsofthebills
Task2:instructions
Thebillsarethemouthpartsofthebirds,alsocalledbeaks.Fromacarefulobservationofthe
imagesofthevariousfinches,tryandsummarizethecharacteristicsofthebillsthatmake
themappropriatetofeedfromseeds,cactus,insectsorbuds.Tryandbeasaccurateas
possible.Youmayalsofindrelevantinformationbrowsingtheinternet.
Task2:participant’sanswer
<starttypingyouranswerhere>
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IntroductiontoBioinformaticsonlinecourse:IBT_2016
Task3:Whatif...theseedsonEspañolastartedtoincreaseinsize?
3.1Whatwouldyouexpecttoseehappentothepopulationoverthenext20years?
<starttypingyouranswerhere>
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3.2WhatwouldyouexpecttohappenimmediatelytothepopulationofSmallGround
Finches?
<starttypingyouranswerhere>
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3.3Whatwouldhappenifthesizeoftheseedsdecreasedagaininthefuture?
<starttypingyouranswerhere>
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Task4:Variationsinthedepthofthebeaks
In1947,LackmeasuredthebeaksizesofthethreedifferentspeciesofGroundFinch(genus
Geospiza)intheGalápagosIslands.Hisdataisrecordedinthegraphsbelow(alsoavailablein
thefileonline):
IntroductiontoBioinformaticsonlinecourse:IBT_2016
4.1DescribethepatternshowninthebeakdepthdistributionforthebirdsonPintaand
Marchena.
IntroductiontoBioinformaticsonlinecourse:IBT_2016
4.2WhathappenstothebeakdepthofG.fulignosaonLosHermanoswhenthereisno
othercompetition?
4.3WhathappenstotherangeinbeakdepthofG.fortisonFloreanaandSanCristobal
comparedtoPintaandMarchena?Whatmaythisindicateaboutthesizeofseedsavailable
ontheseislands?
4.4Darwinonlyobservedonetypeoffinchonthemainland-similartotheGalapagosSmall
GroundFinch.Heproposedthatallfinchesevolvedfromtheonespeciesthatlivedonthe
mainland.HowcouldthedatafromDaphneandLosHermanosbeusedtosupportDarwin’s
theorythatallFinchesevolvedfromacommonancestor?