Transcript Lecture 1 Thursday Jan. 4, 2001

BIOLOGY 3404F
EVOLUTION OF PLANTS
Fall 2008
http://instruct.uwo.ca/biology/3404f
Dr. R. Greg Thorn
Department of Biology, UWO
TODAY’S OUTLINE
• Course introduction and logistics
– Announcements and Contacts
– Grading, Lectures, Labs, Texts
• Introducing your lecturer
• What organisms are we going to study?
• What is systematics?
GRADING
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Assignments 1-35% each (Sep 23, Oct 7, Oct 28)
Essay
15% Tue Nov 18
Midterm Exam
25% 1h Tue Oct 21
Final Lab Exam
15% Mon Dec 1 (in lab)
Final Exam
30% 3h (TBA)
Lectures, Labs & Text
• Lectures emphasize diversity, evolutionary
relationships and importance
• Labs emphasize morphology and recognition
• The required text (to be supplemented by important
journal articles) supplies a good synthesis: Raven,
Evert & Eichorn. 2005. Biology of Plants, 7th ed.
W.H. Freeman, New York. We will use Chapters 1
and 11-20, plus supplemental readings to be provided.
[Chapters 13 and 14 include many non-photosynthetic
organisms that will not be covered in detail.]
Tentative Schedule (synopsis)
• Photosynthetic prokaryotes, protists, fungi,
and bryophytes (Chapters [1, 11, 12],13-16)
• Midterm
• Vascular plants: pteridophytes,
gymnosperms, angiosperms (Ch. 17-20)
• Final exam
WHAT ORGANISMS DO WE STUDY?
• DOMAIN ARCHAEA (= ARCHAEBACTERIA)
• DOMAIN BACTERIA (= EUBACTERIA)
• DOMAIN EUKARYOTA
– KINGDOM PROTISTA
– KINGDOM FUNGI (only their symbionts are
photosynthetic)
– KINGDOM PLANTAE
– KINGDOM ANIMALIA (only their symbionts
are photosynthetic)
Prokaryotes
• Domain Archaea
– Halophiles: Halobacterium (rhodopsin)
– Methanogens
– Thermophiles
• Tremendous genetic diversity
• Many are now being found in environments that
are not extreme - e.g., in soil, root surfaces, etc.
For a moderately modern taxonomic treatment, see
Bergey’s Manual (in library, or online at
http://www.bergeys.org)
Prokaryotes II
• Domain Bacteria [some examples]
• Phylum Proteobacteria: includes Rhizobium in
N2-fixing associations (nodules) with legumes,
and Agrobacterium of plant galls
• Phylum Cyanobcteria: Nostoc, in many lichens,
and Anabaena, found in the water-fern Azolla
• Phylum Actinobacteria: Frankia, in N2-fixing
associations with non-legumes
• More genetic diversity than ALL eukaryotes
The Prokaryote origins of
eukaryotes and photosynthesis
• Purple and green bacteria
(photoautotrophic; not closely related)
• Sources of mitochondria (purple nonsulfur)
and photosynthesis in all plants, algae and
cyanobacteria (PSII from purple sulfur and
PSI from green sulfur)
• Chloroplasts arose by endosymbiosis of a
cyanobacterium into an early eukaryote
KINGDOM PROTISTA
• Includes protists that are fungus-like ("water
molds" and "slime molds”), plant-like ("algae”),
and animal-like ("protozoa")
• [Fungus-like: Myxomycota, Dictyosteliomycota,
Oomycota, etc. – see BIO 3218b]
• Algae: Euglenophyta, Cryptophyta, Rhodophyta,
Dinophyta, Haptophyta, Chrysophyta,
Bacillariophyta, Phaeophyta, Chlorophyta
• [Protozoa: Not covered – see BIO 2240F/G]
KINGDOM FUNGI
• [Phylum Chytridiomycota (water moulds and
rumen fungi)]
• Phylum Glomeromycota (the mycobionts of
endomycorrhizae)
• [Phylum Zygomycota (sugar moulds or bread
moulds)]
• Phylum Ascomycota (includes the mycobionts of
most lichens; others are saprotrophs or pathogens)
• Phylum Basidiomycota (includes the mycobionts
of most ectomycorrhizae; a few others are
mycobionts of basidiolichens; others are
saprotrophs or pathogens)
KINGDOM PLANTAE
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Phylum Bryophyta (mosses)
Phylum Hepatophyta (liverworts)
Phylum Anthocerophyta (hornworts)
[Phylum Zosterophyllophyta]
[Phylum Rhyniophyta]
[Phylum Trimerophyta]
Phylum Psilophyta (psilopsids)
Phylum Lycophyta (clubmosses, spikemosses &
quillworts)
• [xx] = dead
PLANTAE part II
• Phylum Equisetophyta (= Sphenophyta) (horsetails)
• Phylum Pterophyta (= Pteridophyta, Polypodiophyta,
etc.) (ferns)
• [Phylum Pteridospermophyta (seed ferns)]
• Phylum Cycadophyta (cycads)
• Phylum Ginkgophyta (ginkgo)
• Phylum Coniferophyta (conifers)
• Phylum Gnetophyta (gnetophytes)
• Phylum Anthophyta (Angiosperms, "Flowering
Plants")
TAXONOMY & SYSTEMATICS
• Both have to do with classifying and naming
organisms
• Taxonomy is now often regarded as the poor
cousin or antiquated version of systematics –
you won’t find many university departments of
Plant Taxonomy, but you might find a few
university courses with that name
• Folk taxonomies – all around the world, people
have recognized and named the organisms that
are considered useful or dangerous, and often
grouped them in some way
TAXONOMY
• Gk taxis – arrangement + nomos –
management/law
• Webster: the science of classification of
objects
• Raven: the science of the classification of
organisms
• Judd: Theory and practice of grouping
individuals into species, arranging species
into larger groups, and giving these groups
names, thus producing a classification
SYSTEMATICS
• Gk systema – system + atikos – about
• Webster: the science or method of
classifying, especially taxonomy
• Raven: Scientific study of the kinds of
organisms and the relationships between
them
• Judd: The science of organismal diversity,
frequently used in a sense roughly
equivalent to taxonomy
TAXONOMY vs SYSTEMATICS
• If there is any difference, it is that systematics
(post-Darwin) is concerned with creating a
classification that reflects evolutionary
relationships. Taxonomists have in the past
frequently created classifications of
convenience, consisting of easy-to-recognize
groups based on patterns of overall similarity
• Since ~no taxonomists now classify in the
absence of evolutionary evidence, the two terms
are essentially equal
Why base classification on
evolution?
• Knowing the identity of something (or someone)
– its name – is potentially informative of what it
does, where it lives, etc., as well as what it looks
like
• Because related organisms share many traits
(e.g., biochemical pathways, structure,
morphology), a classification that is based on
evolutionary relationships has potential to be
more predictive than one that is not
Next Week
• I will be away!
• No classes, but lecture material will be posted
online
• Evolution
• Geological time scale
• Readings: Chapters 1, 11, and 12
• In Lecture time on Thurs Sep 18 we will take a
hike around campus to see “Plants” in the real
world. Come dressed for it - rain or shine.
• First lab Sept 22, meet in BGS 3015 at 2:30 p.m.
Assignment #1
• See the web link at
http://instruct.uwo.ca/biology/3404f/Lectures.html