Upload
micah
View
151
Download
3
Tags:
Embed Size (px)
DESCRIPTION
Principles of Plant Systematics. The Phylogenetic Approach emphasizes evolutionary relationships between groups. Uses morphological, genetic, and chemical characters to construct a phylogenetic tree, also called a “ cladogram .” - PowerPoint PPT Presentation
Citation preview
Principles of Plant Systematics
• The Phylogenetic Approach emphasizes evolutionary relationships between groups.
• Uses morphological, genetic, and chemical characters to construct a phylogenetic tree, also called a “cladogram.”
• What about other approaches– Cronquist, Thorne, etc? Phylogenetic Approach builds on the previous systems.
Charles Darwin (1809-1882)
Evolution Descent with modification.
Darwin’s Orchid
Angraecum sesquipedale (native to Madagascar)
Darwin's hawk moth, Xanthopan morgani praedicta
A good classification system should be PREDICTIVE
What is a “Plant” ?
• Plants all contain photosynthetic pigments chlorophyll a & b.
• Plants all store carbohydrates, usually in the form of starch.
• Plants all have the presence of two anterior whiplash flagella at some stage of the life cycle, often modified or sometimes lost.
• ???????????????!!!!!!!!!!!!!Footnote: all oxygenic (oxygen produced during light reactions of photosynthesis) photosynthetic organisms use Chlorophyll a.
Chlorophyll a
Chlorophyll b
Starch
Polysaccharide composed of many glucose molecules in alpha 1-4 linkage
OK…what is cellulose?
Chlamydomonas– a green alga with two anterior whiplash flagella.
OK…then what is “Systematics” ?
• Systematics is easier to define than “plant.” • Systematics is the science of organismal
diversity and the relationships between organisms.
• Systematics is the study of the “biological diversity that exists on Earth today and its evolutionary history.
Carolus Linnaeus (before Darwin was born)
What About Linnaean Ranks?
About Linnaean Ranks
• Plants initially grouped mostly by morphology.• Basket groups were made up of plants that didn’t
morphologically seem to fit anywhere else.• Did not at least initially include genetic data which
hadn’t been discovered yet.• Linnaean ranks of same level are not of same
evolutionary age. • We will use Linnaean ranks when they reflect
what we see, but discard them when they do not.
The Phylogenetic Approach is based on Monophyly
• A monophyletic group is a “group composed of an ancestor and all of its descendants”
• Synonyms: monophyletic group= Clade.• A monophyletic group can be removed from
the evolutionary tree with a single cut.• Closest relatives on the evolutionary tree (also
called “cladogram”) are called Sister Groups.
What Does a Cladogram Look Like?
What Does a Cladogram Look Like?
“Dicots” – a Clade?
AsterAles
euro
sids i
i
Bixaceae Malvaceae (incl. Bombacaceae, Sterculiaceae, Tiliaceae) Cistaceae Cytinaceae Muntingiaceae Sarcolaenaceae Dipterocarpaceae Neuradaceae Thymelaeaceae
Angiosperm Phylogeny Flowering Plant Systematics
© Th
eodo
r C.H
. Cole
(Heid
elberg
) and
Hart
mut H
. Hilg
er (B
erlin)
2010
________________________________________________________________________________________- hypothetical tree based on molecular phylogenetic data (Jan 2010); branch lengths deliberate, not expressing actual time scale; position of many characters on tree unclear; if a character is marked as being a potential synapomorphy at a node/for a clade, this does not mean that all members of that clade possess that character; * orders added as of APG III (2009)- this poster depicts only the largest and most important of the currently accepted approx. 450 families (according to APweb 2010); for family characteristics see: Kubitzki K, ed. (1990 ff). - References: APG III (2009); Judd W et al. (2007); Simpson M (2005); Soltis DE et al. (2005); Stevens PF (2010) APweb – www.mobot.org/MOBOT/research/APweb; Watson/Dallwitz (2009) delta-intkey.com/angio/ - Thanks to Christoph Dobeš, Ray F. Evert, Peter H. Raven, Douglas E. Soltis, Peter F. Stevens, Maximilian Weigend, Michael Wink
bark fibrous; hairs often stellate; flw K often valvate,
petals contorted, A often ∞; mucilage, cyclopropenoid fatty acids, flavones
flw often monosymmetric, plunger pollination (long style);
nodes trilacunar; inulin, sesquiterpenes, secoiridoids
Asteraceae Goodeniaceae Pentaphragmataceae Calyceraceae Menyanthaceae Rousseaceae Campanulaceae (incl. Lobeliaceae) Stylidiaceae
endo- sperm scanty
dipsAcAles Adoxaceae Diervillaceae Linnaeaceae
Caprifoliaceae Dipsacaceae Morinaceae Valerianaceae
AmborellAles*
ApiAles Apiaceae Griseliniaceae Pennantiaceae
Araliaceae Myodocarpaceae Pittosporaceae
AquifoliAles Aquifoliaceae Cardiopteridaceae Stemonuraceae
GArryAles
GentiAnAles
lAmiAles
solAnAles Convolvulaceae (incl. Cuscutaceae) Solanaceae (incl. Nolanaceae) Hydroleaceae Montiniaceae Sphenocleaceae
Apocynaceae (incl. Asclepiadaceae) Loganiaceae Gentianaceae Gelsemiaceae Rubiaceae Acanthaceae Lamiaceae Orobanchaceae Plantaginaceae
Bignoniaceae Lentibulariaceae Paulowniaceae Scrophulariaceae Byblidaceae Martyniaceae Pedaliaceae Stilbaceae Gesneriaceae Hydrostachyaceae Oleaceae Phrymaceae Verbenaceae
Eucommiaceae Garryaceae (incl. Aucubaceae)
ericAles
cornAles Cornaceae Grubbiaceae Loasaceae Curtisiaceae Hydrangeaceae Nyssaceae Actinidiaceae Ericaceae Polemoniaceae Sarraceniaceae
Balsaminaceae Fouquieriaceae Primulaceae Styracaceae Clethraceae Lecythidaceae Roridulaceae Theaceae Ebenaceae Myrsinaceae Sapotaceae Theophrastaceae
Ast
erid
s
mAlvAles
brAssicAles
core
eudic
ots
cucurbitAles
rosAles
fAbAles
oxAlidAles
mAlpiGhiAles
celAstrAles
myrtAles
GerAniAles
crossosomAtAles
euro
sids i
cAryophyllAles
cAnellAles
piperAles
lAurAles
mAGnoliAles
sAbiAles
proteAles
vitAles*
sAxifrAGAles
sAntAlAles
GunnerAles
Bataceae Caricaceae Limnanthaceae Salvadoraceae Brassicaceae Cleomaceae Moringaceae Tovariaceae Capparaceae Koeberliniaceae Resedaceae Tropaeolaceae
fAGAles
rosid
s
Betulaceae Fagaceae Myricaceae Rhoipteleaceae Casuarinaceae Juglandaceae Nothofagaceae Ticodendraceae
Anisophyllaceae Coriariaceae Cucurbitaceae Begoniaceae Corynocarpaceae Datiscaceae
nymphAeAles*AustrobAileyAles
rAnunculAles
trochodendrAles*
buxAles*
ZyGophyllAles*
dilleniAles
berberidopsidAles*
Brunelliaceae Connaraceae Elaeocarpaceae Oxalidaceae Cephalotaceae Cunoniaceae Huaceae
Fabaceae Polygalaceae Quillajaceae Surianaceae
Barbeyaceae Elaeagnaceae Rosaceae Cannabaceae Moraceae Ulmaceae Dirachmaceae Rhamnaceae Urticaceae (incl. Cecropiaceae)
Celastraceae Lepidobotryaceae (incl. Hippocrateaceae, Brexiaceae) Parnassiaceae Achariaceae Euphorbiaceae Ochnaceae Podostemaceae
Chrysobalanaceae Hypericaceae Passifloraceae Rhizophoraceae Clusiaceae Linaceae Phyllanthaceae Salicaceae Erythroxylaceae Malpighiaceae Picrodendraceae Violaceae
Krameriaceae Zygophyllaceae
Combretaceae Myrtaceae Penaeaceae (incl. Oliniaceae) Lythraceae (incl. Punicaceae, Sonneratiaceae, Trapaceae) Melastomataceae (incl. Memecylaceae) Onagraceae Vochysiaceae
Francoaceae Geraniaceae Ledocarpaceae Melianthaceae
Crossosomataceae Stachyuraceae Strasburgeriaceae Geissolomataceae Staphyleaceae
Vitaceae
mAGnoliids
eudi
cots
euAs
teri
ds i
woody; parasites or semiparasites; without mycorrhiza; lvs margin entire; flw A epipetalous,
perianth often simple, valvate, persisting; polyacetylenes, triterpene sapogenins, silicic acid
Altingiaceae Daphniphyllaceae Hamamelidaceae Cercidiphyllaceae Grossulariaceae Paeoniaceae Crassulaceae Haloragaceae Saxifragaceae
Balanophoraceae Misodendraceae Opiliaceae Loranthaceae Olacaceae Santalaceae (incl. Viscaceae) Aizoaceae Caryophyllaceae Molluginaceae Polygonaceae
Amaranthaceae Didiereaceae Nepenthaceae Portulacaceae [incl. Chenopodiaceae] Droseraceae Nyctaginaceae Simmondsiaceae Basellaceae Drosophyllaceae Phytolaccaceae Talinaceae Cactaceae Frankeniaceae Plumbaginaceae Tamaricaceae
Dilleniaceae
Aextoxicaceae Berberidopsidaceae
Gunneraceae Myrothamnaceae
Buxaceae (incl. Didymelaceae) Haptanthaceae
Trochodendraceae
Nelumbonaceae Platanaceae Proteaceae
Berberidaceae Eupteleaceae Menispermaceae Ranunculaceae Circaeasteraceae Lardizabalaceae Papaveraceae Sabiaceae
Amborellaceae
Austrobaileyaceae Schisandraceae (incl. Illiciaceae) Trimeniaceae
Cabombaceae Hydatellaceae Nymphaeaceae
Canellaceae Winteraceae
Annonaceae Eupomatiaceae Magnoliaceae Degeneriaceae Himantandraceae Myristicaceae
Calycanthaceae Hernandiaceae Monimiaceae Gomortegaceae Lauraceae Siparunaceae
Aristolochiaceae Piperaceae Hydnoraceae Saururaceae
woody, vessels lacking; dioecious; flw T5–8, A∞, G5–8; 1 ovule/carpel; embryo sac 9-nucleate; 1 species (New Caledonia)
aquatic, herbaceous; cambium absent; aerenchyma; flw T4–12, A3–∞; embryo sac 4-nucleate; seeds operculate, perisperm; mucilage; alkaloids (no benzylisoquinolines)
woody, vessels solitary; flw T>10, A∞, G ca.9; embryo sac 4-nuceate; tiglic acid, aromatic terpenoids
woody; pollen uniporate; aromatic terpenoids
± herbaceous; lvs two-ranked, leaf base sheathing; single adaxial prophyll; swollen nodes
woody; pith septate; lvs two-ranked; ovules with obturator; endosperm ruminate
woody; lvs opposite; flw with hypanthium, staminodes frequent, often valvate anthers; carpels with 1 ovule; embryo large
euAs
teri
ds ii
lvs often divided; flw whorled, P single or multiple whorls, G apocarpous/paracarpous, superior;
berberines
mostly woody; flw tepals often 4-merous, A epitepalous, connectives sometimes with apical appendage
mostly herbaceous; without mycorrhiza; G often unilocular with central placentation,
pollen copate, surface spiny; betalains or anthocyanins (latter, e.g., in Caryophyllaceae)
lvs with glandular teeth; often hypanthium, apically unfused carpels, stigma decurrent; fr mostly dry, dehiscent;
myricetin, flavonols
flw pentacyclic, parts alternating,
G connate,K + C (free),
(A polyandrous), pollen tricolporate;
trihydroxyl-flavonoids
lvs with glandular teeth; flw A obdiplostemonous, nectary on filament;
stems jointed at nodes; ethereal oils, ellagic acidlvs opposite, colleters (glandular hair on adaxial surface of petiole base),
stipules small (if any); cork deep seated; flw K valvate, persisting, A incurved in bud, ovary inferior; ovules many;
endosperm scanty; scaly bark; flavonols, myricetin
flw small, G often 3-merous, nectary: intrastaminal disk; seeds often with aril (red-orange);
infl cymose
lvs margins toothed; flw G often tricarpellate
lvs often compound, pulvini (sleep movement); flw A5 or multiple, branched style common;
mucilage cells; oxalates
flw often “papilionaceous”: wing, standard, keel, mostly G1, mostly A10; fr a pod; symbiosis with root nodule bacteria;
diverse alkaloids, NP amino acids, lectins (in Fabaceae)
lvs mostly simple with stipules; flw K valvate (and hypanthium) persisting,
carpels with 1 ovule, stigma dry; dihydroflavonols
lvs mostly alternate; flw often unisexual, G mostly inferior,
parietal placentation; cucurbitacins
lvs undivided; flw small, unisexual, anemophilous, thus T reduced or lacking, G mostly inferior;
infl spikes or catkins; fr 1-seeded, mostly nuts; ectomycorrhiza; tannins, dihydroflavonols
lvs alternate; flw often 4-merous, often clawed petals, A often many, 2×K;
hypogynous (often gynophore); infl racemose; myrosin cells, glucosinolates
mostly woody; lvs mostly undivided, hydathode teeth; flw often 4-merous, K much smaller than C, persisting,
intrastaminal disk, G inferior; fr drupaceous; diverse iridoids
mostly sympetalous, nectary gynoecial, ovules unitegmic,
endosperm cellular; iridoids common
lvs teeth, theoid; nodes unilacunar; flw 5-merous, pentacyclic;
nonhydrolyzable tannins, ellagic acid, hydroquinones
lvs opposite, colleters; flw corolla convolute in bud;
indole alkaloids; iridoidslate sympetaly
lvs opposite; nodes 1:1; flw mostly monosymmetric, A often 2(+2); ethereal oils in gland-headed hairs;
6-oxygenated flavones, rosmarinic acid, oligosaccharides: cornoside, verbascoside (acetoside)
lvs spiral, simple; nodes unilacunar; flw petals plicate; K persisting;
diverse alkaloids, no iridoids
woody; lvs serrate; flw 1-2 ovules/carpel, C± free, K slightly connate;
fr drupe with broad stigma
woody (except Apiaceae); lvs often divided; nodes usu. multilacunar;
infl mostly umbel; drupe or schizocarp (Apiaceae: mericarp/carpophore)
lvs opposite, often basally connate; nodes 3:3; buds with scales;
flw often monosymmetric; K persistent in fruit; secoiridoids
earlysympetaly
fl small embryo short
G inf
erior
woody; flw 4–5-merous, nectary: disk, A epipetalous, G syncarpous; pollen colporate; endosperm helobial; triterpenoids
woody; vessels lacking; idioblasts in cortex; flw tepals missing, A∞, G>5 laterally connate with abaxial nectaries; fr aggregate of follicles
mostly woody; unisexual, dioecious; lvs evergreen, stomata cyclocytic; flw tepals ± uniform or missing; pregnan pseudoalkaloids
unisexual, dioecious; lvs toothed, sec. veins palmate;flw tepals small to lacking;
ellagic acid
often tendrillar vines; lvs often divided and with glandular teeth; A epipetalous, 2 ovules per carpel; raphides, pearl glands;
berries
woody; K + C, stylodia free;
hypanthium, nectary disk
cork origin deep-seated; endosperm lacking;
resinous, lignans/neolignans, harman alkaloids
woody; dioecious; flw small, C valvate, G unilocular; fruit indehiscent;
iridoids (aucubin), gutta
mostly woody; lvs veins proceed to apex & teeth; flw K5–∞, persisting; mostly A∞, G mostly slightly connate;
seeds often with aril; fr often both ventrally/dorsally dehiscent
pollen tricolpate; flw K/C/P opp A;
filaments rather narrow, anthers basifixed; nodes trilacunar;
stomata anomocytic; ethereal oils absent
features as in “Early Angiosperms”
borAGinAles Boraginaceae (incl. Codon) Ehretiaceae (incl. Lennoaceae) Hydrophyllaceae
Cordiaceae Heliotropiaceae Wellstediaceae ?
woody; lvs stomata cyclocytic, petiole bundles annular; fr fleshy;
calcium oxalate as crystals
lvs roughly hairy; nodes unilacunar; infl scorpioid; mostly 4 ovules;
isokestose, higher inulins, pyrrolizidine alkaloids
A=C, epipetalous polyandry
rare, G(2)
AcorAles
AlismAtAles
petrosAviAles*
dioscoreAles
pAndAnAles
liliAles
ArecAles
poAles
commelinAles
ZinGiberAles
AspArAGAles
monocots
commelinids
Alstroemeriaceae Corsiaceae Melanthiaceae Philesiaceae Colchicaceae Liliaceae Petermanniaceae Smilacaceae
Bromeliaceae Eriocaulaceae Poaceae Restionaceae Xyridaceae Cyperaceae Juncaceae Rapateaceae Typhaceae (incl. Sparganiaceae)
Arecaceae
Commelinaceae Haemodoraceae Pontederiaceae
Cannaceae Heliconiaceae Marantaceae Strelitziaceae Costaceae Lowiaceae Musaceae Zingiberaceae
Amaryllidaceae (incl. Agapanthaceae, Alliaceae) Asparagaceae (incl. Agavaceae, Hyacinthaceae, Ruscaceae) Hypoxidaceae Iridaceae Lanariaceae Orchidaceae Xanthorrhoeaceae (incl. Asphodelaceae, Hemerocallidaceae)
Cyclanthaceae Pandanaceae Velloziaceae
Burmanniaceae Dioscoreaceae Nartheciaceae Taccaceae
Alismataceae (incl. Limnocharitaceae) Juncaginaceae Ruppiaceae Aponogetonaceae Butomaceae Posidoniaceae Scheuchzeriaceae Araceae Hydrocharitaceae Potamogetonaceae Zosteraceae
Petrosaviaceae
Acoraceae
atactostele (scattered bundles), no secondary thickening;
mostly herbaceous; pollen monosulcate;
sieve tube plastids with protein crystals;
sympodial branching; vascular bundles in stem scattered;
lvs parallel-veined, entire, no glandular teeth;
flw pentacyclic, P 3-merous, A opp. P, filaments narrow,
anthers broadly attached, septal nectary; single cotyledon;
adventitious roots
infl spadix with spathe; lvs axils with mucilaginous intravaginal squamules; ovules atropous, with epidermal perisperm and copious endosperm; idioblasts with ethereal oils
mostly herbs and aquatics; rhizomatous; hydrophilous; intravaginal squamules; flw G apocarpous; placentation often laminal; endosperm helobial; embryo large/green
often geophytes; anomalous sec. growth; flw nonspotted tepals, septal nectaries; capsule or berry;
seed coat obliterated or with phytomelan
often geophytes (bulbs, tubers, rhizomes); flw tepals sometimes spotted, nectaries at tepals; many seeds, seeds coat (testa) cellular;
phytomelan lacking; fructans in stems, chelidonic acid, steroid saponins
often twining vines; lvs often reticulate; ovary often inferior, style short, branched; steroid sapogenins/alkaloids
some woody (with terminally tufted leaves), flw spadix
monopodial, woody; lvs pinnately pseudocompound, reduplicate-plicate; intense primary growth, large apical meristem;
infl with spathe; alkaloids
mostly herbaceous; epidermis siliceous; mostly mycorrhiza absent; lvs grassy; flw often anemophilous, minute, chaffy, without nectaries
flw often irregular; few fertile stamens; infl thyrsus of scorpioid cymes;
phenylphenalenones
rhizomatous, large-leafed herbs; pseudostem: central infl; flw irregular/monosymmetric, septal nectaries, G inferior, A often strongly modified/reduced;
seeds arillate; silicic acid
stem with ring of bundles; fr a follicle; East Asia
UV-fluorescing cell walls (ferulic/coumaric acids);
silicic acid in leaves; cuticular waxes often in rodlets
aggregated into scallops
cerAtophyllAles Ceratophyllaceaeaquatic, herbaceous; lvs whorled, no pellucid dots; vessels lacking; monoecious;
flw T9–10, A∞, G1, 1 apical ovule/carpel, pollen inaperturate, pollen tube branched; hydrophilous
eArl
y AnG
iosp
erms
woody; vessels absent, eustele; nodes;sieve tube plastids with starch grains; lvs simple, persistent, entire; flw parts free, strobilar, perfect, P parts varying, often in threes, weakly differentiated, stamen with broad filaments, pollen monosulcate; G apocarpous (style short in most), nectaries absent; embryo very small; aromatic terpenoids
infl cymose
ellagic acid lacking
ellag
ic ac
id tan
nins
lvs with stipules
axial nectary
common
nodes trilacunar
sesq
uiterp
enes
benz
yliso
quino
line a
lkaloi
ds;
embr
yo sa
c 8-nu
cleate
ethere
al oil
s in s
pheri
cal id
ioblas
ts (pe
llucid
dots)
benz
yliso
quino
lines
abse
nt
N fix
embryo large, endosperm scanty
endosperm nuclear helobial,nectaries
when present septal
Ca oxalate raphides
fr us
ually
1–
few-se
eded
chlorAnthAles* Chloranthaceaelvs opposite, interpetiolar stipules; nodes swollen;
flw small T0–3, A1–5, G1, 1 apical ovule/carpel
sApindAles Anacardiaceae Meliaceae Rutaceae Simaroubaceae
Burseraceae Nitrariaceae Sapindaceae
mostly woody (silica/silicified);lvs alternate, odd-pinnately compound;
flw often imperfect, intrastaminal disk; ethereal oils
huerteAles* Dipentodontaceae Gerrardinaceae Tapisciaceaevessel elements: scalariform perforations; mucilage cells;
lvs margins toothed, stipules cauline; flw small, A = and opposite K, ovules 1-2/carpel;
AnitA
GrAde
pArAcryphiAles* Paracryphiaceae
bruniAles* Bruniaceae Columelliaceae (incl. Desfontainiaceae)
escAlloniAles* Escalloniaceaemostly woody; infl racemose, C free,
anthers basifixed, nectary disc
woody, evergreen; nodes 1:1; flw polysymmetric, anthers basifixed
woody; infl racemose, flw 4-merous, filaments stout, capsule septicidal
picrAmniAles* Picramniaceaetrees; lvs spiral; extrafloral nectaries;
staminate flw: A = and opposite C; bark bitter, anthraquinones
embryo large
How Is a Cladogram Interpreted?
• It is not a graph, in the sense that the axes are not labeled.
• It shows relationships. • An evolutionary tree must be rooted to know
which changes are relatively recent and which occurred further in the past. Piece of string analogy.
• Rooting is done using an outgroup.An outgroup is a relative of the groups under study. The outgroup separated from the ingroup lineage before the ingroup diversified.
Outgroup Separated before the Ingroup Diversified
Determining Evolutionary History
• There is uncertainty whenever more than two lineages diverge from a single point.
• Groups that include a common ancestor but only some and not all of its descendents are called paraphyletic. Separate lineages diverging from different ancestors are without a true common ancestor are called polyphyletic.
How Is a Cladogram Interpreted?
What is a Synapomorphy?
• A synapomorphy is a shared derived character state. Synapomorphies can be used to define species and evolutionary events in a cladogram. Shown as “tic” marks on cladograms.
• A symplesiomorphy is a shared ancestral character state. Symplesiomorphies are not helpful in defining current taxa. Synapomorphies may be become symplesiomorphic over evolutionary time.
Strength of Evidence for a Clade
• Evidence is strongest for those groups that have the most synapomorphies, morphological, chemical, genetic, etc. (any kind of synapomorphy.)
• The more “tic” marks leading to a monophyletic group (clade) the stronger the evidence for it.
How Is a Cladogram Interpreted?
Asparagales
Homology
• Identity by descent• A character is homologous if the species in
question all inherited the trait from a common ancestor.
• A seal’s front fins are homologous to our arms.• Our arms are not homologous to those of a
spider.
Homoplasy
• Similarity without identity by descent.• Can be caused by parallelism (i.e., “convergent
evolution) in two unrelated lineages.• Can be caused by a reversal of a character
state within a lineage.• Homoplasies make it much harder to
determine evolutionary history (i.e., to construct an accurate cladogram.)