Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
BIOL 448.34
Systematic Botany. Lecture 34
Alexey Shipunov
Minot State University
November 23, 2011
BIOL 448.34
Outline
Questions and answersClassification of angiosperms
Basal angiospermsMagnoliidae—“ANTITA” clade
BIOL 448.34
Outline
Questions and answersClassification of angiosperms
Basal angiospermsMagnoliidae—“ANTITA” clade
BIOL 448.34
Questions and answers
Previous final question: the answer
Why angiosperms conquered the land?
I They filled ecological niche of seed herbs because ofoptimized life cycle
I Then they expanded to the tree level again because theyblocked succession pathways («cenophobe» theory)
BIOL 448.34
Questions and answers
Previous final question: the answer
Why angiosperms conquered the land?
I They filled ecological niche of seed herbs because ofoptimized life cycle
I Then they expanded to the tree level again because theyblocked succession pathways («cenophobe» theory)
BIOL 448.34
Questions and answers
Classification of angiosperms
Questions and answersClassification of angiosperms
BIOL 448.34
Questions and answers
Classification of angiosperms
Milestones of angiosperm classificationI Carolus Linnaeus (XVIII century) gathered all available
information, established species and generaI Michel Adanson and Antoine Jussieau (end of XVIII)
established plant familiesI John Lindley (middle of XIX) invented plant ordersI Alfred Engler and Charles Bessey (XIX-XX) started
evolutionary classificationsI Arthur Cronquist, Rolf Dahlgren, Armen Takhtajan and
Robert Thorne (XX-XXI) developed different well-arguedcontemporary classifications based on morphology
I From 1993, Angiosperm Phylogeny Group (APG) as wellas several individuals started to employ molecularcharacters. Luckily, one of the most accessible chloroplastDNA genes, rbcL, appeared to be extremely useful fortracing changes on family and order levels
BIOL 448.34
Questions and answers
Classification of angiosperms
Taxonomic map of angiosperms: subclasses
BIOL 448.34
Questions and answers
Classification of angiosperms
Taxonomic map: orders
BIOL 448.34
Questions and answers
Classification of angiosperms
Dendrogram of subclasses
BIOL 448.34
Questions and answers
Classification of angiosperms
Cladogram of subclasses
BIOL 448.34
Questions and answers
Classification of angiosperms
Paraphyly
BIOL 448.34
Questions and answers
Classification of angiosperms
Magnoliidae portrait
Nymphaea sp. (water-lily)
BIOL 448.34
Questions and answers
Classification of angiosperms
Liliidae portrait
Acorus calamus (calamus, or sweet flag)
BIOL 448.34
Questions and answers
Classification of angiosperms
Rosidae portrait
Geranium sp. (wild geranium)
BIOL 448.34
Questions and answers
Classification of angiosperms
Asteridae portrait
Penstemon sp. (beard-tongue)
BIOL 448.34
Questions and answers
Classification of angiosperms
Evolutionary history of subclasses
I Magnoliidae are historically most ancient, first fossilsappear in Late Jurassic. They dominate fresh waters andmaybe, filled lower floors of forests in Cretaceous
I Liliidae appeared in Lower Cretaceous, they started todominate grasslands in Neogene
I Rosidae appeared in Lower Cretaceous, they madebroad-leaf forests in Late Cretaceous and onwards
I Asteridae originated in Middle Cretaceous, they started arapid divergence in Paleogene
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Basal angiospermsMagnoliidae—“ANTITA” clade
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Archaefructus
I Fossil water plant from lower Cretaceous of ChinaI Very primitive fructifications which are not yet compacted
in flowerI Multiple free carpels, paired stamens
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Archaefructus reconstruction
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Amborella
I Small forest shrub of New Caledonia (big island in Pacificocean)
I Have irregular flowers, stylar canal, unusual embryo sac(with three synergids and no antipods)
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Amborella, branch with male flowers
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Amborella, diagram and formula
∂P9−11A12−21; ∂P7−8St2G4−6(where “St”are staminodes, non-functional stamens)
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Amborella stylar canal
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Trithuria
I Wetland and water plants from south Asia and AustraliaI Have unusual structure of fructifications (“non-flowers”)
where male organs typically positioned in the center of?inflorescence/flower
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Trithuria general view
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Trithuria fructification
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Summary
I From four subclasses of angiosperms, two (Magnoliidaeand Rosidae) are paraphyletic
I Fossil Archaefructus, Amborella and Trithuria are mostprimitive angiosperms
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Final question (3 points)
Which of four subclasses is basal? Why?
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
Final question (3 points)
Which of four subclasses is basal? Why?
BIOL 448.34
Basal angiosperms
Magnoliidae—“ANTITA” clade
For Further Reading
Margulis and Chapman. 2009.Kingdoms and domains: an illustrated guide to the phyla oflife on Earth. 4th edition.