BIOLOGY 3404 F EVOLUTION OF PLANTS Fall 2008

BIOLOGY 3404 F EVOLUTION OF PLANTS Fall 2008 http: //instruct. uwo. ca/biology/3404 f 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 • • • Assignments 1 -35% each (Sep 23, Oct 7, Oct 28) Essay 15% Tue Nov 18 Midterm Exam 25% 1 h Tue Oct 21 Final Lab Exam 15% Mon Dec 1 (in lab) Final Exam 30% 3 h (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, 7 th 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, 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 N 2 -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 N 2 -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 3218 b] • Algae: Euglenophyta, Cryptophyta, Rhodophyta, Dinophyta, Haptophyta, Chrysophyta, Bacillariophyta, Phaeophyta, Chlorophyta • [Protozoa: Not covered – see BIO 2240 F/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 • • 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/3404 f/Lectures. html