BIOLOGY 3404F EVOLUTION OF PLANTS Fall 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 Exam25%1h Tue Oct 21 Final Lab Exam15%Mon Dec 1 (in lab) Final Exam30%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 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 ) 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

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 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 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