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7/27/2019 04 Classification
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Classification of Classification of
AngiospermsAngiosperms
Classification of AngiospermsClassification of Angiosperms
•• important non-Western systemsimportant non-Western systems
•• Parashara (India) 2000 BCParashara (India) 2000 BC
•• ChineseChinese
•• AztecsAztecs
•• EgyptiansEgyptians
•• folk systematics (ethnotaxonomy)folk systematics (ethnotaxonomy) —— scientific?scientific?
•• classification is the 3rd goal of systematicsclassification is the 3rd goal of systematics
•• ancient search forancient search for ““naturalnatural”” system of classificationsystem of classification
Folk ClassificationsFolk Classifications•• 5-6 categories5-6 categories
•• arranged hierarchicallyarranged hierarchically
•• unique beginnerunique beginner = kingdom= kingdom
•• plant, animalplant, animal
Folk ClassificationsFolk Classifications•• 5-6 categories5-6 categories
•• arranged hierarchicallyarranged hierarchically
•• unique beginner = kingdomunique beginner = kingdom
•• life formslife forms (tree, vine, grass)(tree, vine, grass)
Unique form: cactus in Tzeltal (Mayan)Unique form: cactus in Tzeltal (Mayan)
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Folk ClassificationsFolk Classifications•• 5-6 categories5-6 categories
•• arranged hierarchicallyarranged hierarchically•• unique beginner = kingdomunique beginner = kingdom
•• life formslife forms (tree, vine, grass)(tree, vine, grass)
Unique form : strangler - Aguaruna (Peru)Unique form : strangler - Aguaruna (Peru)
Folk ClassificationsFolk Classifications•• 5-6 categories5-6 categories
•• arranged hierarchicallyarranged hierarchically•• unique beginner = kingdomunique beginner = kingdom
•• life forms (tree, vine, grass)life forms (tree, vine, grass)
•• genericgeneric
•• 500 +/- in most systems500 +/- in most systems
•• most important levelmost important level
•• similar to Theophrastus,similar to Theophrastus,
Linnaeus, etc.Linnaeus, etc.
Folk ClassificationsFolk Classifications•• 5-6 categories5-6 categories
•• arranged hierarchicallyarranged hierarchically
•• unique beginner = kingdomunique beginner = kingdom
•• life forms (tree, vine, grass)life forms (tree, vine, grass)
•• genericgeneric
•• 500 +/- in most systems500 +/- in most systems•• most important levelmost important level
•• similar to Theophrastus,similar to Theophrastus,
Linnaeus, etc.Linnaeus, etc.
•• specific/varietalspecific/varietal
•• 1-3 at most1-3 at most
•• more in special plantsmore in special plants
Folk ClassificationsFolk Classifications
Are these indigenous, innateAre these indigenous, innate
classifications non-scientific?classifications non-scientific?
62% of folk genera match62% of folk genera match
““scientificscientific”” species!species!
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Folk ClassificationsFolk Classifications
Are these indigenous, innateAre these indigenous, innate
classifications non-scientific?classifications non-scientific?
Tzeltal classification recognizesTzeltal classification recognizes one folkone folk
genus for 2+ scientific speciesgenus for 2+ scientific species about 20%about 20%
Lantana
Folk ClassificationsFolk Classifications
Are these indigenous, innateAre these indigenous, innate
classifications non-scientific?classifications non-scientific?
Tzeltal classification recognizesTzeltal classification recognizes one folkone folk
genus for 2+ scientific generagenus for 2+ scientific genera about 14%about 14%
Pinus Abies
Folk ClassificationsFolk Classifications
Are these indigenous, innateAre these indigenous, innate
classifications non-scientific?classifications non-scientific?
Tzeltal classification recognizesTzeltal classification recognizes 2+ folk2+ folk
species for 1 scientific speciesspecies for 1 scientific species about 3%about 3%
pepperspeppers
Folk ClassificationsFolk Classifications
Are these indigenous, innateAre these indigenous, innate
classifications non-scientific?classifications non-scientific?
Tzeltal classification recognizesTzeltal classification recognizes 2+ folk2+ folk
species for 1 scientific speciesspecies for 1 scientific species about 3%about 3%
Over-differentiation in 4 ethnotaxonomiesOver-differentiation in 4 ethnotaxonomies
involveinvolve importantimportant taxataxa
pepperspeppers
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Folk ClassificationsFolk Classifications
Further evidence that all humans perceiveFurther evidence that all humans perceive
biodiversity and classify in similar waysbiodiversity and classify in similar ways
HanunHanunóóoo
1. Level of 1. Level of polytypypolytypy in genera (monotypicin genera (monotypic
= 1 sp. per genus, etc.) is similar= 1 sp. per genus, etc.) is similar
worldwideworldwide
# species / genus# species / genus
#
g e n e r a
#
g e n e r a
Folk ClassificationsFolk Classifications
Further evidence that all humans perceiveFurther evidence that all humans perceive
biodiversity and classify in similar waysbiodiversity and classify in similar ways
2. Level of 2. Level of polytypypolytypy of folk classificationof folk classification
andand ““scientificscientific”” flora is identical!flora is identical!
HanunHanunóóoo
# species / genus# species / genus
#
g e n e r a
#
g e n e r a
Systems of ClassificationsSystems of Classifications
Examine three main systems of Examine three main systems of
classifications and how theyclassifications and how they ““evolvedevolved”” in thein the
context of western civilizationcontext of western civilization
Artificial ClassificationsArtificial Classifications
Theophrastus (372-287 BC) took theTheophrastus (372-287 BC) took the
philosophical ideas of Plato and Aristotlephilosophical ideas of Plato and Aristotle
and applied them to taxonomyand applied them to taxonomy
‘‘essentialismessentialism’’
““a genus is any group of a genus is any group of
species that may bespecies that may be
logically and exhaustivelylogically and exhaustively
distinguished on the basisdistinguished on the basis
of one or a very fewof one or a very few
essential propertiesessential properties””
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Artificial ClassificationsArtificial Classifications
Theophrastus (372-287 BC) took theTheophrastus (372-287 BC) took the
philosophical ideas of Plato and Aristotlephilosophical ideas of Plato and Aristotleand applied them to taxonomyand applied them to taxonomy
herbherb subshrubsubshrub shrubshrub treetree
HabitHabit as an essential characteras an essential character
De Historia Plantarum De Historia Plantarum
Theophrastus saw aTheophrastus saw a linear gradationlinear gradation whenwhen
essences are used to arrange organismsessences are used to arrange organisms
‘‘essentialismessentialism’’
Artificial ClassificationsArtificial Classifications
This linear gradation concept is theThis linear gradation concept is the
AristotleanAristotlean Scalae NaturaeScalae Naturae oror GreatGreat
Chain of BeingChain of Being oror Ladder of LifeLadder of Life
Scalae Naturae
Concept of Concept of ladder of lifeladder of life still aroundstill around
today and causes much of thetoday and causes much of the
controversy surrounding evolutioncontroversy surrounding evolution
Unidirectional progressionUnidirectional progression andand rankrank onon
ladder leads to (false) ideas of ladder leads to (false) ideas of
relationships -relationships - fish fish more closelymore closely
related torelated to molluscsmolluscs than fish are tothan fish are to
humanshumans
Artificial ClassificationsArtificial Classifications
Evolution does not advocate thisEvolution does not advocate this
““ladderladder”” of life, but rather advocates aof life, but rather advocates a
““branching treebranching tree””
Evolution asserts (testable!) that fishEvolution asserts (testable!) that fish
are more closely related to humansare more closely related to humansbecause they have a more recentbecause they have a more recent
common ancestor Acommon ancestor A than the commonthan the common
ancestorancestor BB with molluscswith molluscs
A
B
Artificial ClassificationsArtificial Classifications
. . . back to Theophrastus and his. . . back to Theophrastus and his
classification of plantsclassification of plants
herbherb subshrubsubshrub shrubshrub treetree
•• logical but rigid system of classificationlogical but rigid system of classification
—— a prioria priori choice of characterschoice of characters
•• clearlyclearly artificialartificial as conifers areas conifers are
placed with some (woody)placed with some (woody)angiosperms and some (woody) fernsangiosperms and some (woody) ferns
white pinewhite pine
red oakred oak
tree ferntree fern
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Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
•• association of plant taxonomy withassociation of plant taxonomy with
medicine goes back to Dioscorides (ADmedicine goes back to Dioscorides (AD
60)60)
•• here prescribinghere prescribing ““mandrakemandrake”” in thein the
nightshade familynightshade family
•• family Dioscoreaceaefamily Dioscoreaceae – – yam familyyam family – –
named after this doctornamed after this doctor
Dioscorea villosa Dioscorea villosa --
wild yamwild yam
Source of edible yam; sources of Source of edible yam; sources of
steroids, cortisones, first oralsteroids, cortisones, first oral
contraceptives (diosgenin,contraceptives (diosgenin,
progesterone)progesterone)
Dioscorea sp. Dioscorea sp.
Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
•• association of plant taxonomy withassociation of plant taxonomy with
medicine goes back to Dioscorides (ADmedicine goes back to Dioscorides (AD60)60)
•• publishedpublished De Materia Medica De Materia Medica
in which medicinal plants werein which medicinal plants were
listed by medicinal propertieslisted by medicinal properties
Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
•• after Dark Ages, renewed interest inafter Dark Ages, renewed interest in
medicinal value of herbs due to greatmedicinal value of herbs due to greatplagues of 15-16plagues of 15-16thth centuriescenturies
•• invention of Europeaninvention of European
printing press in 15printing press in 15thth centurycentury
facilitated printing of facilitated printing of
information intoinformation into ‘‘herbalsherbals’’
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Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
•• little emphasis placed on system of little emphasis placed on system of
classification of the plantsclassification of the plants —— alphabeticalalphabetical
or medicinal propertyor medicinal property
•• less than 1000 species of less than 1000 species of
plants were known; no need forplants were known; no need for
intricate classification systemintricate classification system
in thein the herbalsherbals
Artificial ClassificationsArtificial Classifications
HerbalistsHerbalists : a second group using artificial: a second group using artificial
systems of classificationsystems of classification
•• herbals often lavishly illustratedherbals often lavishly illustrated
•• herbalists referred to as theherbalists referred to as the
‘‘German Fathers of BotanyGerman Fathers of Botany’’ De Historium Stirpium De Historium S tirpium - Fuchs- Fuchs
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
•• world-wide trade and explorationworld-wide trade and exploration ——
manymany new plant speciesnew plant species were seen bywere seen by
European taxonomistsEuropean taxonomists Linnaeus & studentsLinnaeus & students’’ travelstravels
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
•• world-wide trade and explorationworld-wide trade and exploration ——
manymany new plant speciesnew plant species were seen bywere seen by
European taxonomistsEuropean taxonomists Sir Joseph Banks (1768-1771)Sir Joseph Banks (1768-1771)
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1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
•• world-wide trade and explorationworld-wide trade and exploration ——
manymany new plant speciesnew plant species were seen bywere seen by
European taxonomistsEuropean taxonomists Sir Joseph Banks (1768-1771)Sir Joseph Banks (1768-1771)
•• moremore formal system of formal system of
classificationclassification waswas
necessarynecessary
•• suites of instrinsicsuites of instrinsic
characterscharacters of plants neededof plants needed
to be usedto be used
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
Andrea Caesalpino (1519-1603) - Italian doctorAndrea Caesalpino (1519-1603) - Italian doctor
•• struggled with questionstruggled with question how to form ahow to form a
moremore ‘‘naturalnatural’’ classificationclassification
•• private collection of 768 plantsprivate collection of 768 plants
arranged in 266 sheets in 3 volumesarranged in 266 sheets in 3 volumes
•• arranged by reproductive featuresarranged by reproductive features
of the plants -of the plants - flowers and fruitsflowers and fruits
•• firstfirst natural systemnatural system, first, first
herbarium, first botanical gardenherbarium, first botanical garden
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
Andrea Caesalpino (1519-1603) - Italian doctorAndrea Caesalpino (1519-1603) - Italian doctor
•• firstfirst natural systemnatural system, first, first
herbarium, first botanical gardenherbarium, first botanical garden
Pisa, ItalyPisa, Italy
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
John Ray (1628-1705) - English blacksmithJohn Ray (1628-1705) - English blacksmith
•• argued thatargued that all parts of the plantall parts of the plant
should be usedshould be used in classificationin classification•• classified 18,000 species inclassified 18,000 species in
Methodus Plantarum Methodus Plantarum (1703)(1703)
first byfirst by fruitfruit types andtypes and
subdivided bysubdivided by flowerflower andand leaf leaf
featuresfeatures
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1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
John Ray (1628-1705) - English blacksmithJohn Ray (1628-1705) - English blacksmith
•• first recognized distinction betweenfirst recognized distinction between dicotsdicots
andand monocotsmonocots
2525 ‘‘classesclasses’’ of dicotsof dicots
44 ‘‘classesclasses’’ of monocotsof monocots
== ordersorders todaytoday
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
Pierre Magnol (1638-1715) - French botanistPierre Magnol (1638-1715) - French botanist
•• considered Rayconsidered Ray’’s system of 29s system of 29 ‘‘classesclasses’’
too cumbersometoo cumbersome
•• classified 76classified 76 ‘‘familiesfamilies’’ —— first to recognizefirst to recognize
familyfamily levellevel ((MagnoliaceaeMagnoliaceae honored after him)honored after him)
1580 - 1800: Pivotal Period1580 - 1800: Pivotal Period
Artificial or Natural Systems?Artificial or Natural Systems?
Carolus Linnaeus (1707-1778) - SwedishCarolus Linnaeus (1707-1778) - Swedish
taxonomisttaxonomist
•• work of Caesalpino, Ray, andwork of Caesalpino, Ray, and
Magnol in producing aMagnol in producing a workableworkable
classification systemclassification system culminated inculminated in
LinnaeusLinnaeus’’ Sexual SystemSexual System
•• however, this classification systemhowever, this classification system
was awas a backward stepbackward step in the progressin the progress
towardstowards natural systemsnatural systems
Linnaeus - Sexual SystemLinnaeus - Sexual System
What did he do?What did he do?
•• $125 grant in 1732 funded 5 month$125 grant in 1732 funded 5 month
floristic inventory of Laplandfloristic inventory of Lapland
•• priceless collection was thepriceless collection was theimpetus for his treatment of theimpetus for his treatment of the
world-wide floraworld-wide flora
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Linnaeus - Sexual SystemLinnaeus - Sexual System
What did he do?What did he do?
•• greatest achievement -greatest achievement - SpeciesSpecies
PlantarumPlantarum in 1753 arranged asin 1753 arranged as
Systema SexualeSystema Sexuale
•• classification based onclassification based on
reproductive features likereproductive features like
Caesalpino, but selective andCaesalpino, but selective and
features chosenfeatures chosen a prioria priori simplysimply
onon workabilityworkability
Linnaeus - Sexual SystemLinnaeus - Sexual System
Take a closer look insideTake a closer look inside SpeciesSpecies
PlantarumPlantarum
•• prime divisions based onprime divisions based on number of number of
stamensstamens
•• secondary divisions based onsecondary divisions based on
number of pistilsnumber of pistils
•• was Linnaeus a sexist?was Linnaeus a sexist?
•• not here! number of stamens morenot here! number of stamens more
variable than of pistils -variable than of pistils - essential for aessential for a
mechanical, workable systemmechanical, workable system
Linnaeus - Sexual SystemLinnaeus - Sexual System
How does it work?How does it work? OenotheraOenothera
biennisbiennis or evening primroseor evening primrose
•• OenotheraOenothera has 1 pistil (but 4 fusedhas 1 pistil (but 4 fused
carpels) - placed incarpels) - placed in Monogynia Monogynia (2(2nd nd level)level)
•• OenotheraOenothera has 8 stamens - placed inhas 8 stamens - placed in
OctandriaOctandria (1(1st st level)level)
Linnaeus - Sexual SystemLinnaeus - Sexual System
Note thatNote that OenotheraOenothera is placed with otheris placed with other
genera of the family Onagraceaegenera of the family Onagraceae
Gaura Epilobum
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Linnaeus - Sexual SystemLinnaeus - Sexual System
Linnaeus and followers DID realize thatLinnaeus and followers DID realize that
the system would have issuesthe system would have issues
•• cacti and cherries have little overallcacti and cherries have little overall
similarity to each othersimilarity to each other
OpuntiaOpuntia
PrunusPrunus
•• but both have many stamens and a singlebut both have many stamens and a single
pistilpistil —— placed inplaced in Polyandria / MonogyniaPolyandria / Monogynia
•• Linnaeus more concerned withLinnaeus more concerned with mechanics:mechanics:
usable, predictable, expandable, immutableusable, predictable, expandable, immutable
•• Sexual System artificial, and thus backwardSexual System artificial, and thus backward
step towardsstep towards ‘‘naturalnatural”” classificationsclassifications
•• taxonomists reconsideredtaxonomists reconsidered
purposes of classification;purposes of classification;
revisited olderrevisited older ‘‘naturalnatural’’ ideasideas
Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• late 18th century sawlate 18th century saw
accumulation of botanicalaccumulation of botanical
collectionscollections
•• Linnaeus had provided popularLinnaeus had provided popular
and efficient cataloguing schemeand efficient cataloguing scheme
but unrelated plants were oftenbut unrelated plants were often
groupedgrouped
Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• the number and diversity of the number and diversity of
tropical plants in Senegaltropical plants in Senegal
influencedinfluenced Michel AdansonMichel Adanson
•• grouped plants by affinitiesgrouped plants by affinities
observed among multipleobserved among multiple
relationships of characteristicsrelationships of characteristics
•• published his classification inpublished his classification in
Familles des PlantesFamilles des Plantes in 1763in 1763
David BaumDavid Baum is the world expert onis the world expert on
the evolution and pollinationthe evolution and pollination
biology of the baobabs - mainlybiology of the baobabs - mainly
found in Madagascar - named afterfound in Madagascar - named after
Michel Adanson.Michel Adanson.•• Adansonia Adansonia - the baobabs- the baobabs
What is one of the twoWhat is one of the two
main pollinators that Davidmain pollinators that David
photographed visitingphotographed visiting
flowers of the baobabs?flowers of the baobabs?
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Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• de Jussieude Jussieu family of Parisfamily of Paris
produced the most completeproduced the most complete
‘‘naturalnatural’’ classificationclassification
•• their natural system came fromtheir natural system came from
the practice of the practice of ‘‘taxonomictaxonomic gardensgardens’’
Antoine-Laurent de JussieuAntoine-Laurent de Jussieu
Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• private and public gardens were thenprivate and public gardens were then
arranged according to the Linnaeanarranged according to the Linnaean
Sexual SystemSexual System of classificationof classification
Linnaean Gardens in Uppsala, SwedenLinnaean Gardens in Uppsala, Sweden
Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• Bernard de Jussieu experimented byBernard de Jussieu experimented by
replanting in the Trianon Garden onreplanting in the Trianon Garden on
Versailles Palace grounds so that those mostVersailles Palace grounds so that those most
““similarsimilar”” looking on the basis of manylooking on the basis of manyfeatures would be in proximityfeatures would be in proximity
Bernard -
uncle
Antoine -
nephew
Natural ClassificationsNatural Classifications
Period of Natural Systems: 1760 - 1880Period of Natural Systems: 1760 - 1880
•• Antoine Laurent de Jussieu publishedAntoine Laurent de Jussieu published
Genera PlantarumGenera Plantarum in 1789 based on the dein 1789 based on the de
Jussieu familyJussieu family’’s new, mores new, more naturalnatural
classification systemclassification system - and today reflected- and today reflectedin the plantings at the Trianon Gardensin the plantings at the Trianon Gardens
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Phylogenetic ClassificationsPhylogenetic Classifications
Phylogenetic systems date to 1859 and publication of Phylogenetic systems date to 1859 and publication of
Origin of SpeciesOrigin of Species by Charles Darwinby Charles Darwin
Phylogenetic ClassificationsPhylogenetic Classifications
Phylogenetic systems date to 1859 and publication of Phylogenetic systems date to 1859 and publication of
Origin of SpeciesOrigin of Species by Charles Darwinby Charles Darwin
•• ‘‘NaturalNatural’’ had meant different things tohad meant different things to
different peopledifferent people
•• to Linnaeus and othersto Linnaeus and others ‘‘naturalnatural’’ referredreferred
to the ordered structure of the universe andto the ordered structure of the universe and
biota as ordained by God -biota as ordained by God - specific orspecific or
special creationspecial creation
•• to others this grouping of taxa into largerto others this grouping of taxa into larger
groupsgroups implied relationships based onimplied relationships based on
genealogygenealogy - with or without a God- with or without a God
Phylogenetic ClassificationsPhylogenetic Classifications
Phylogenetic systems to Darwin must includePhylogenetic systems to Darwin must include
genealogy + amount of change (or similarity)genealogy + amount of change (or similarity)
•• ““classification must be genealogicalclassification must be genealogical””
•• ““genealogy alone does not givegenealogy alone does not giveclassificationclassification””
•• ““descent with modificationdescent with modification”” : or: or
genealogy plus change = evolutiongenealogy plus change = evolution
Phylogenetic ClassificationsPhylogenetic Classifications
Phylogenetic systems represented byPhylogenetic systems represented by
thethe ““treetree”” metaphormetaphor
•• Darwin argued thatDarwin argued that ““commoncommon
ancestryancestry”” is a factis a fact —— and outcomeand outcome
is a phylogeneticis a phylogenetic ‘‘treetree’’
•• less than a decade later Ernstless than a decade later Ernst
Haeckel published the firstHaeckel published the first tree of tree of
lifelife
•• all classification systems sinceall classification systems since
have beenhave been phylogeneticphylogenetic
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Phylogenetic ClassificationsPhylogenetic Classifications
Bentham & Hooker at Kew Royal Botanic Gardens firstBentham & Hooker at Kew Royal Botanic Gardens first
systematists to wrestle with phylogenetic classificationssystematists to wrestle with phylogenetic classifications
George BenthamGeorge Bentham
1800-18841800-1884Joseph HookerJoseph Hooker
1817-19111817-1911
•• provided Darwin withprovided Darwin with
much of his botanicalmuch of his botanical
evidence for evolutionevidence for evolution
•• rudimentaryrudimentary
phylogenetic systemphylogenetic system
quickly over-shadowed byquickly over-shadowed by
two younger Germanstwo younger Germans
Phylogenetic ClassificationsPhylogenetic Classifications
Engler and Prantl produced the monumentalEngler and Prantl produced the monumental Die Die
Naturlichen Pflanzenfamilien Naturlichen Pflanzenfamilien between 1887-1915between 1887-1915
Adolph EnglerAdolph Engler
1844-19301844-1930Karl PrantlKarl Prantl
1849-18931849-1893
Phylogenetic ClassificationsPhylogenetic Classifications
Engler and Prantl produced the monumentalEngler and Prantl produced the monumental Die Die
Naturlichen Pflanzenfamilien Naturlichen Pflanzenfamilien between 1887-1915between 1887-1915
Adolph EnglerAdolph Engler
1844-19301844-1930Karl PrantlKarl Prantl
1849-18931849-1893
•• original classificationoriginal classification
waswas ‘‘naturalnatural’’ and basedand based
on many characterson many characters
•• by 1915 their systemby 1915 their system
had ahad a phylogeneticphylogenetic flavorflavor
withwith simple plantssimple plants listedlisted
first andfirst and progressing toprogressing to
moremore complex plantscomplex plants
Phylogenetic ClassificationsPhylogenetic Classifications
Engler - Prantl classification system became the standardEngler - Prantl classification system became the standard
to arrange herbaria and floras by early 20to arrange herbaria and floras by early 20 thth centurycentury
•• stressed thatstressed that ““simplesimple”” flowersflowers
- that is with few or no parts -- that is with few or no parts -
werewere ““primitiveprimitive””
•• e.g.,e.g., ““AmentiferaeAmentiferae”” - a group- a group
with reduced flowers werewith reduced flowers were
considered primitiveconsidered primitive
•• their system can be calledtheir system can be called
““simple = primitivesimple = primitive”” oror ““SalixSalix
= primitive= primitive””
SalixSalix - willow- willow
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Phylogenetic ClassificationsPhylogenetic Classifications
Charles Bessey revolutionized the classification of Charles Bessey revolutionized the classification of
angiosperms by his ideas onangiosperms by his ideas on primitive vs. advanced charactersprimitive vs. advanced characters
•• hypothesized thehypothesized the primitiveprimitive
vs. advanced statevs. advanced state of manyof many
characters of plants -characters of plants - seesee
handout handout
•• BesseyBessey’’ss ‘‘dictadicta’’ or rules wereor rules were
the basis of his phylogeneticthe basis of his phylogenetic
classification schemeclassification scheme
•• formed the basis for allformed the basis for all
subsequent modern systemssubsequent modern systems
Charles Bessey (1848-1915)Charles Bessey (1848-1915)
at University of Nebraskaat University of Nebraska
Phylogenetic ClassificationsPhylogenetic Classifications
What wereWhat were BesseyBessey’’ss main dicta or rules?main dicta or rules?
epigynoushypogynous4. Ovary position4. Ovary position
zygomorphyactinomorphy3. Floral symmetry3. Floral symmetry
parts fusedparts separate2. Floral fusion2. Floral fusion
loss of parts, few innumber
all present, many innumber
1. Floral parts1. Floral parts
Advanced StateAdvanced StatePrimitive StatePrimitive StateCharacterCharacter
Phylogenetic ClassificationsPhylogenetic Classifications
BesseyBessey’’ss dicta or rulesdicta or rules
•• similar tosimilar to foliar theoryfoliar theory of theof the
flowerflower
•• ““ Magnolia Magnolia = primitive= primitive”” ideaidea
•• general trend in angiospermsgeneral trend in angiosperms
has beenhas been reduction, loss, andreduction, loss, and
fusionfusion
Phylogenetic ClassificationsPhylogenetic Classifications
BesseyBessey’’ss classification (classification (‘‘cactuscactus’’))
•• Bessey produced aBessey produced a
classification system based onclassification system based on
his ruleshis rules
•• ordersorders (-ales) of flowering(-ales) of flowering
plants attached showingplants attached showing
relationships and degree of relationships and degree of
primitive vs. advanced featuresprimitive vs. advanced features
•• orderorder RanalesRanales (( Magnolia Magnolia))
considered most primitiveconsidered most primitivepolypetalypolypetaly
hypogynyhypogyny
actinomorphicactinomorphic
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Phylogenetic ClassificationsPhylogenetic Classifications
BesseyBessey’’ss classification (classification (‘‘cactuscactus’’))
•• zygomorphy, fused petals,zygomorphy, fused petals,
and inferior ovary are foundand inferior ovary are found
further up the chartfurther up the chart
•• orderorder RanalesRanales (( Magnolia Magnolia))
considered most primitiveconsidered most primitive
sympetaly
epigynyactinomorphic
polypetaly
epigyny
actinomorphic
sympetaly
hypogyny
zygomorphic
polypetaly
hypogyny
actinomorphic
Phylogenetic ClassificationsPhylogenetic Classifications
Contemporary classificationsContemporary classifications
•• most based onmost based on BesseyBessey’’ss
principlesprinciples
•• which characters stressed,which characters stressed,
though, varies (subjective)though, varies (subjective)
TakhtajanTakhtajan CronquistCronquist
ArmenArmen TakhtajanTakhtajan’’s ands and ArthurArthur
CronquistCronquist’’s are similar withs are similar with
subclassessubclasses (-idae) as the major(-idae) as the major
groupingsgroupings
Phylogenetic ClassificationsPhylogenetic Classifications
Contemporary classificationsContemporary classifications
•• most based on Besseymost based on Bessey’’ss
principlesprinciples
•• which characters stressed,which characters stressed,
though, varies (subjective)though, varies (subjective)TakhtajanTakhtajan CronquistCronquist
CronquistCronquist’’s best developed of thes best developed of the
contemporary classificationscontemporary classifications
based on morphologybased on morphology
Phylogenetic ClassificationsPhylogenetic Classifications
Contemporary classificationsContemporary classifications
•• Rolf DalhgrenRolf Dalhgren (d. 1987):(d. 1987):
Danish taxonomist whoDanish taxonomist who
emphasizedemphasized chemicalchemical featuresfeatures
DalhgrenDalhgren
•• Robert ThorneRobert Thorne (Rancho Santa(Rancho SantaAna Botanical Garden): stillAna Botanical Garden): still
modifying his morphologymodifying his morphology
based system using DNAbased system using DNA
evidenceevidence
ThorneThorne
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Phylogenetic ClassificationsPhylogenetic Classifications
Molecular classificationsMolecular classifications
•• the 1993 paper examining DNAthe 1993 paper examining DNA
of 500 genera of seed plantsof 500 genera of seed plants
revolutionized phylogeneticrevolutionized phylogenetic
classificationclassification
Phylogenetic ClassificationsPhylogenetic Classifications
Molecular classificationsMolecular classifications
•• Angiosperm Phylogeny GroupAngiosperm Phylogeny Group
classificationclassification —— APGI (1998);APGI (1998);
APGII (2003) used inAPGII (2003) used in Plant Plant
SystematicsSystematics texttext
•• APGIIIAPGIII (2009)(2009) – – used in courseused in course
Phylogenetic ClassificationsPhylogenetic Classifications
Molecular classificationsMolecular classifications
•• APGAPG uses DNA and a lot of uses DNA and a lot of
morphologymorphology
•• e.g., use of pollene.g., use of pollen
features to delimitfeatures to delimit
““eudicoteudicot”” – – the 3-poredthe 3-pored
pollen bearing floweringpollen bearing flowering
plantsplants
•• Angiosperm Phylogeny GroupAngiosperm Phylogeny Group
classificationclassification —— APGI (1998);APGI (1998);
APGII (2003) used inAPGII (2003) used in Plant Plant
SystematicsSystematics texttext
•• APGIIIAPGIII (2009)(2009) – – used in courseused in course
Phylogenetic ClassificationsPhylogenetic Classifications
Molecular classificationsMolecular classifications
•• Angiosperm Phylogeny GroupAngiosperm Phylogeny Group
classificationclassification —— UW BotanyUW Botany
Gardens first garden based onGardens first garden based on
the APG system!the APG system!
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Issues in GroupingIssues in Grouping
1. Convergence a problem with any system1. Convergence a problem with any system
•• repeated shifts torepeated shifts to wind pollinationwind pollination && reduced flowersreduced flowers
Issues in GroupingIssues in Grouping
1. Convergence a problem with any system1. Convergence a problem with any system
•• repeated shifts torepeated shifts to inferior ovariesinferior ovaries
Issues in GroupingIssues in Grouping
1. Convergence a problem with any system1. Convergence a problem with any system
•• repeated shifts torepeated shifts to corolla tubescorolla tubes• various trees that you will see in this coursevarious trees that you will see in this course
Issues in GroupingIssues in Grouping
2.2. ““Tree ThinkingTree Thinking”” - what a phylogenetic tree is . . .- what a phylogenetic tree is . . .
R
R
R
rootedrooted rootedrooted
rootedrootedunrootedunrooted
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Issues in GroupingIssues in Grouping
2.2. ““Tree ThinkingTree Thinking”” - what a phylogenetic tree is- what a phylogenetic tree is notnot . . .. . .
FishFish NewtNewt LizardLizard MouseMouse HumanHuman
Is a newt more closely related to a fish than to a human?Is a newt more closely related to a fish than to a human?
NoNo! this is the ancestor of ! this is the ancestor of
human and newthuman and newt
Tip reading is ladder reading, incorrect!Tip reading is ladder reading, incorrect!
FishFish NewtNewtLizardLizardMouseMouseHumanHuman
Issues in GroupingIssues in Grouping
2.2. ““Tree ThinkingTree Thinking”” - what a phylogenetic tree is- what a phylogenetic tree is notnot . . .. . .
XX XX XX XX
ancestor of human andancestor of human and
newtnewt
Issues in GroupingIssues in Grouping
3. Named groups are3. Named groups are monophyleticmonophyletic (ancestors and all(ancestors and all
descendants)descendants)
= ancestor= ancestor
Issues in GroupingIssues in Grouping
3. . . . vs.3. . . . vs. paraphyleticparaphyletic (not all descendants included - usually(not all descendants included - usually
because these are highly modified)because these are highly modified) - should these be allowed?- should these be allowed?
= ancestor= ancestor
= excluded descendant= excluded descendant
= modifications= modifications
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Issues in GroupingIssues in Grouping
3. e.g.3. e.g. CaesalpinoidCaesalpinoid legumes arelegumes are paraphyleticparaphyletic
•• faboidfaboid (beans, peas)(beans, peas)
andand mimisoidmimisoid
(acacia, mimosa)(acacia, mimosa)
legumes are highlylegumes are highly
modifiedmodified
•• but descendedbut descended
from the commonfrom the common
ancestor of ancestor of
caesalpinoidscaesalpinoids
Issues in GroupingIssues in Grouping
3. . . . vs.3. . . . vs. polyphyleticpolyphyletic (more than one ancestor - defined by(more than one ancestor - defined by
convergent feature)convergent feature) - these are avoided- these are avoided
= ancestor= ancestor
= convergence= convergence
Issues in GroupingIssues in Grouping
4. Not all monophyletic groups are named -4. Not all monophyletic groups are named - limited categorieslimited categories
available in ranked (Linnean) systemsavailable in ranked (Linnean) systems
= named group= named group
= not named group= not named group
Issues in GroupingIssues in Grouping
5. Ranks are abitrary -5. Ranks are abitrary - but follow Linnean categories:but follow Linnean categories:
kingdom, phylum, class, order, family, genus, specieskingdom, phylum, class, order, family, genus, species
MagnoliophytaMagnoliophyta
PinophytaPinophyta
GnetophytaGnetophyta
CycadophytaCycadophyta
GinkgophytaGinkgophyta
GymnospermsGymnosperms= 4 phyla= 4 phyla
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Issues in GroupingIssues in Grouping
5. Ranks are abitrary -5. Ranks are abitrary - but follow Linnean categories:but follow Linnean categories:
kingdom, phylum, class, order, family, genus, specieskingdom, phylum, class, order, family, genus, species
MagnoliophytaMagnoliophyta
PinopsidaPinopsida
GnetopsidaGnetopsida
CycadopsidaCycadopsida
GinkgopsidaGinkgopsida
GymnospermsGymnosperms
= 4= 4 classesclasses in 1in 1
phylumphylum
PinophytaPinophyta
or . . .or . . .
Issues in GroupingIssues in Grouping
6. International Code of 6. International Code of
Phylogenetic Nomenclature orPhylogenetic Nomenclature orPhyloCodePhyloCode (established 2004)(established 2004)
•• taxon based on phylogenytaxon based on phylogeny
(a(a ““cladeclade””) - rankless) - rankless
•• content of taxon specifiedcontent of taxon specified
by the phylogeny or treeby the phylogeny or tree
•• any clade can be namedany clade can be named
http://www.ohiou.edu/phylocode/http://www.ohiou.edu/phylocode/
International CodeInternational Code of of
NomenclatureNomenclature oror ““rankedranked”” //““LinneanLinnean”” systemsystem
vs.vs.
•• ranked taxon defined basedranked taxon defined based
on typeson types
•• content of defined taxon notcontent of defined taxon not
specified except for typespecified except for type
•• limited number of groups orlimited number of groups or
ranks can be namedranks can be named
Issues in GroupingIssues in Grouping
•• in practice and informally,in practice and informally,
recent phylogeneticrecent phylogenetic
classifications have beenclassifications have been
using a hybrid of ranked andusing a hybrid of ranked andrankless groupingsrankless groupings
APG IIIAPG III
•• APGIII usesAPGIII uses ranksranks forfor
families and ordersfamilies and orders; informal; informal
rankless names for largerrankless names for larger
groupsgroups