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Speciation (last outline) Understanding Evolutionary Relationships phylogenies / cladograms. Tuesday 11/12/13. Exam 3 – Thurs 11/21 st -- covers material up through Tues 11/19
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Speciation (last outline) • Understanding Evolutionary Relationships • phylogenies / cladograms Tuesday 11/12/13 • Exam 3 – Thurs 11/21st • -- covers material up through Tues 11/19 • -- lab on 11/19 will be VERY helpful covering plant material which will be on the exam! Vertebrates will NOT be on the exam • -- Can’t do a review session unless you want it on Monday 11/18?? • My office hours Weds 1:00-3:00 • Shelley’s office hours Tuesday after class • Ben’s – Weds: 4:30 to 5:30 in the Life Sciences Library • Plants • overview of plant evolution • evolution of terrestrial plants • adaptations to life on land • in depth look at plant phyla • nonvascular plants // seedless vascular plants • seed vascular plants
Diversity lectures (plants & animals): • relate structure & function • understand the concept of adaptation • how have • ex: • which structures • ex:
Four major periods of plant evolution: Plant Diversity fig 30.2
Adaptation onto land: • plants evolved from green algae • ~450 million years ago (mya) • Evolved adaptations: • gametangia • cuticle • stomata
Adaptation onto land: • more adaptations: • roots & shoots • mycorrhizae • lignin
Adaptation onto land: • continued adaptations: • vascular tissue • seeds fig. 14.8
Plant life cycle -- Alternation of Generations: Figure 30.3 Plants alternate between haploid and diploid stages. Haploid – Diploid – Chromosomes contain the genes Cell divisions: mitosis – meiosis –
Plant life cycle -- Alternation of Generations: Figure 30.3 • Gametophyte (haploid) • produces gametes • Sporophyte (diploid) • produces • dispersing multicellular in both stages
Bryophyte: Mosses • earliest land plants -- 450 mya • adapted to • lacks vascular tissue gametophyte generation:
Life cycle of mosses see figure 30.6 dominant generation – male gametes - sporophyte spores dispersed in air
Ferns • first vascular plants -- ~350mya • evolutionary step -- • still moist habitat • sporophyte most visible
Life cycle ferns mitosis • dominant generation - sporophyte mitosis see fig 30.10
Seed Plants: • Gametophytes -- microscopic • multicellular - • pollen grain– • ovules - • seed -- • Gymnosperms (360mya) • Angiosperms (130mya)
Conifers Gymnosperms: ~350+mya • Major evolutionary steps: Gingkos Cycads
Confiers: • heterosporous - 2 types of spores • seed develops inside
Pine Tree Life Cycle: • dominant generation: • sporophyte (pine tree) • may be • specialization depending on habitat • e.g., see figure 30.13
Angiosperms - flowering plants ~130mya • major evolutionary steps: • flowers -- • fruit --
Showy Flowers - • adaptation for
Angiosperm life cycle: • pollen dispersed via wind/animals • double fertilization • seed • ovary develops into fruit
Dispersal of seeds: • advantageous to disperse • does not • passive wind dispersal
Fruits: Dispersal of Seeds: • passive dispersal • active dispersal • fruit consumed–
Asexual reproduction in angiosperms: • Vegetative Propagation • cuttings • runners • e.g., • rhizomes • fragmentation