Download Part 1 – Biodiversity *sample*

Part1–Biodiversity*sample*
Chordates,
Molluscs,120,000 50,000
Protozoa,100,000 Algae,300,000
Other,250,000
Plants,320,000
Fungi,1,500,000
Anthropods,
4,050,000
Nematodes,
500,000
Whatisaspecies?
o Agroupoflivingorganismsconsistingofsimilarindividualscapableofexchanginggenes
orinterbreeding.
o A‘new’speciesarisefromtaxonomicchangesthateither‘split’or‘lump’species.
Biologicalspeciesconcept,1942
§ Groupsofinterbreeding/(potentialinterbreeding)naturalpopulationsthatare
reproductivelyisolatedfromotherpopulations.
Limitations:difficulttoapplywhenpopulationsongeographicallyseparatedandspeciesmaybe
morphologicallydifferentbuthybridizenaturallyincertaincircumstance.
Morphologicalspeciesconcept
§ Speciesdefinedbysimilarmorphology(size,shape,appearance)anddistinguishedby
theirdifferences.
§ Classicapproachwhendescribingspecies
Limitations:Morphologycanvarygeographicallyandwithdifferentenvironmentalconditions.
Crypticspeciesthatmaylookmorphologicallyidenticalmaybegeneticallydifferent.
Recognitionspeciesconcept
§ Agroupofindividualsthatcanrecognizeeachotheraspotentialmates(evenifthey
don’tactuallyinterbreed)
Phylogeneticspeciesconcept
§ Agroupofindividualsthatshareacommonancestorandcanbedistinguishedfrom
othergroupsofindividuals
CrypticSpecies–Clade
o Morphologysimilarordifferentbetweengeneticallydifferentspecies/clades
o EightcladesaroundAustraliashowednomorphologicaldifference,patterns
inconsistentbetweenspecies
o Femalemorphology,highlyvariable,withnophylogeneticorgeographicbias.
o GroupsofmorphologicallyindistinguishablemalesoccurredinQLD&WA.
o Evencloselyrelatedcladeswerenotmorphologicallysimilar.
Phylogeneticspeciesconcept
§ Focusedongeneticdifferences,particularlyevolutionaryrelationships.
§ Asetofpopulationshaveauniquecombinationofcharactersthatdifferfromanyother
‘related’species
Therealityofspecies:
Ø Taxonomyisnotfixed–therearealwaysongoingchangesthatoccurwithnew
techniquese.g.geneticadvances
Ø Nosingleapproachanddifferentdefinitionsofaspeciesresultindifferent
classifications
Ø Widespreaduseofgenetictechniqueshasbroughtaboutmajorchangesto
taxonomy
Ø Typically,classificationsarebasedonacombinationofapproaches,including
considerationofgeneticrelatedness,morphologyandgeographicdistribution.
Part2:GlobalTourofbiodiversity*sample*
Parta:BacteriatoProtists
Twosuperkingdoms
Archaea
• Morespecialized
• Restrictedenvironment,manyliveinextremeconditions(e.g.hotthermalsprings,near
volcanicventsontheseafloor)oranaerobicconditions
• Somegrowattemperaturesover100°C
• Mayoccupyconditionsotherbacteriaoreukaryotescannot
Bacteria
• Mostdiversegroup
• Maybebeneficial,harmfulorhavenoaffectonorganisms
• Generallysinglecellswithsimpleshapes(rods,spheres,spirals,filaments)
•
•
Prokaryotesdon’thavemembraneorganelles(nucleus,mitochondria)
Bothpositivelyandnegativelyusedin:
Foodproduction
Medicine
Agriculture(nitrogenfixation&breakdownoforganicmatter)
-Viruses
Ø Subcellular
Ø Canonlyreproduceinthecellsoftheirhosts
Ø Manycausediseaseinplantsandanimals(includinghumans)
Ø Eachvirusinfectsparticularhostspecies
Ø E.g.Myxomatosis–rabbitcontrol
Lifecycleofavirus
Transmissionstage:
o Vironsaremetabolicallyinactiveandvirusistransferringtoitshost
o Genomeofthevirus,eitherRNAorDNAisinaproteinorlipid
o Itisinthedispersalformandcanspreadthroughcoughing,sneezing,foodcontamination
ect.
o Vectororganisms-airbornvirusesthroughmosquitos,mitesect
Reproductivestage:
o Vironentersacellofasuitablehost,itsgenometakesoverfromthehostsgenesand
makethehoststartreproducingthevirus
o Copiesarethencombinedwithviralproteins(almostmadeinthehostcell)toformnew
Virons
o Virusvs.immunesystem.Virusevolvesandchangesinordertosurvivedespitethe
immunesystem
KingdomProtista
Anextraordinarydiversecollectionofeukaryoticorganisms
o Eukaryotes–cellscontainseveralmembranelinescompartmentse.g.nucleus,
mitochondria
o Polyphyletic–notasinglecommonancestor
o Taxonomyisnotyetclear,numerousevolutionaryorigins
o Mostaresinglecelledorganismsandmostliveinaquaticenvironments.Canalsobe
colonialormulticellular
o Atleast100,000speciesandmorebeingdiscovered
o Differentsourcesofenergy:
- Photosynthetice.g.algae
- Parasitice.g.malariaPlasmodium
- Predatoryortakeinsmallfoodparticlesfromsurroundings