46
The Wonderful World of Green Plant Diversity and Evolution Biol 366 Spring 2014

The Wonderful World of Green Plant Diversity and Evolution

  • Upload
    donkor

  • View
    46

  • Download
    0

Embed Size (px)

DESCRIPTION

The Wonderful World of Green Plant Diversity and Evolution. Biol 366 Spring 2014. Tree of Life: The Big Picture. Bacteria. Archaea. Eukaryotes. now. membrane-bound nucleus, organelles, etc. >2 bya. >3.5 bya. ca. 4 bya. Fig. 1.1 from Simpson. Green plants share:. - PowerPoint PPT Presentation

Citation preview

Page 1: The Wonderful World of Green Plant Diversity and Evolution

The Wonderful World of Green Plant Diversity and

Evolution

Biol 366Spring 2014

Page 2: The Wonderful World of Green Plant Diversity and Evolution

Tree of Life: The Big Picture

EukaryotesArchaeaBacteria

ca. 4 bya

now

>3.5 bya

>2 bya

membrane-boundnucleus, organelles, etc.

Page 3: The Wonderful World of Green Plant Diversity and Evolution

Fig. 1.1 from Simpson

Page 4: The Wonderful World of Green Plant Diversity and Evolution

Green plants share:• Chlorophylls a (ancestral) and b

• Starch storage

• Stellate flagellar structure

• Certain gene transfers from the chloroplast to the nucleus

• And other features (see Ch. 3)

Page 5: The Wonderful World of Green Plant Diversity and Evolution

Green plant diversity:• Ca. 350,000 species

• Two major groups: 1) chlorophytes (marine and other green algae) and 2) streptophytes [freshwater green algae and embryophytes (= land plants)]

• A major branch (clade) in the eukaryotic Tree of Life

Page 6: The Wonderful World of Green Plant Diversity and Evolution

Fig. 3.1 from Simpson

Page 7: The Wonderful World of Green Plant Diversity and Evolution

Some definitions• Clade = branch on an evolutionary tree,

a lineage, includes an ancestor and all its descendants. Ex.: Green plants, chlorophytes, land plants.

• Paraphyletic group = a group that includes an ancestor and some (but not all) of its descendants, indicated by double quotation marks. Ex.: “Green algae”

Page 8: The Wonderful World of Green Plant Diversity and Evolution

Chlorophytes

Page 9: The Wonderful World of Green Plant Diversity and Evolution

Fig. 3.1 from Simpson

Page 10: The Wonderful World of Green Plant Diversity and Evolution

Basal streptophytes

desmids

Spirogyra

CharaNitella

(Judd et al. 2008)

Page 11: The Wonderful World of Green Plant Diversity and Evolution

Conjugation inSpirogyra

Haplontic life cycle (haploid dominantor zygotic meiosis)

The only diploid cellIs the zygote

zygote (2n)

haploid body

Page 12: The Wonderful World of Green Plant Diversity and Evolution

biology.unm.edu

mason.gmu.edu

CharalesHaplontic but some havemulticellular gametangia(gamete-producing structures)

Page 13: The Wonderful World of Green Plant Diversity and Evolution

Generalized charophyte life cycle:Alternation of generations

XX

gametangia

gametophyte

Page 14: The Wonderful World of Green Plant Diversity and Evolution

Embryophytes (land plants) share:

• Cuticle• Alternation of generations (multicellular

sporophyte and multicellular gametophyte)• Multicellular gametangia (gamete-producing

structures)• Multicellular sporangium (spore-producing

structure)• Embryo (young sporophyte)• Parenchyma? (more likely ancestral)

Page 15: The Wonderful World of Green Plant Diversity and Evolution

Generalized embryophyte life cycle:Alternation of generations

Page 16: The Wonderful World of Green Plant Diversity and Evolution

Bryophytes• Hornworts, liverworts, mosses• Gametophyte-dominant• No vascular tissue (except conducting

cells in a few mosses)• Separate male and female

gametophytes• Sperm must swim to the egg, therefore

need water for fertilization and therefore must remain small

Page 17: The Wonderful World of Green Plant Diversity and Evolution

hornworts

liverwortsmosses

Page 18: The Wonderful World of Green Plant Diversity and Evolution

Plant Tree of Life: Embryophtes

Tracheophytes(vascular plants)HornwortsLiverworts

ca. 450 mya

now Mosses“Bryophytes”

Page 19: The Wonderful World of Green Plant Diversity and Evolution

Liverwort gametophyte

Page 20: The Wonderful World of Green Plant Diversity and Evolution

Liverwortthallus showing air pores

Page 21: The Wonderful World of Green Plant Diversity and Evolution

LiverwortMulticellular gametangia(male = antheridia)

Page 22: The Wonderful World of Green Plant Diversity and Evolution

LiverwortMulticellular gametangia (female = archegonia)OogamyRetention of zygote within the female gametophyteMulticellular embryo

Page 23: The Wonderful World of Green Plant Diversity and Evolution

Hornworts

G

S

Page 24: The Wonderful World of Green Plant Diversity and Evolution

Moss male gametangia(= antheridia)

Capsule = sporangium of the sporophyte

Page 25: The Wonderful World of Green Plant Diversity and Evolution

Generalized embryophyte life cycle:Alternation of generations

Page 26: The Wonderful World of Green Plant Diversity and Evolution

Tracheophytes (vascular plants)• Vascular tissue (tracheids) present• Include lycophytes (quillworts, clubmosses,

spikemosses), monilophytes (ferns, horsetails, whisk ferns), and spermatophytes (seed plants)

Page 27: The Wonderful World of Green Plant Diversity and Evolution

Fig. 4.1 from Simpson

Page 28: The Wonderful World of Green Plant Diversity and Evolution

Lycophytes & Monilophytes

• Quillworts, clubmosses & spikemosses (= lycophytes); ferns, whisk-ferns, & horsetails (= monilophytes);

• Independent gametophytes and sporophytes• Sperm must still swim to the egg• Most are homosporous; a few evolved

heterospory• Many homosporous ferns have means of

avoiding self-fertilization

Page 29: The Wonderful World of Green Plant Diversity and Evolution

Lycophytes

Selaginella (spikemoss)

Lycopodium and friends (clubmosses)

Isoetes (quillwort)

Page 30: The Wonderful World of Green Plant Diversity and Evolution

Whisk-fern (Psilotum)

Ferns (Leptosporangia)

Monilophytes (ferns, horsetails, whisk ferns)

horsetails

Page 31: The Wonderful World of Green Plant Diversity and Evolution

1n

2n

2n2n

2n

1n spores

gametophyte

sporophyte

Nutritionally independentsporophytes andgametophytes

Page 32: The Wonderful World of Green Plant Diversity and Evolution

Fern Life Cycle,Fig. 4.32, Simpson

Page 33: The Wonderful World of Green Plant Diversity and Evolution

Lignophytes (woody plants) & Spermatophytes (seed plants)

• Secondary xylem (wood) & bark, heterospory, seeds, eustele, pollen (also pollen tube, pollination droplet)

• Includes gymnosperms and angiosperms

Page 34: The Wonderful World of Green Plant Diversity and Evolution

Fig. 5.1 from Simpson

Page 35: The Wonderful World of Green Plant Diversity and Evolution

Gymnosperms• Conifers, gingko, cycads, Gnetales

• Molecular data support this group as having a single common ancestor

• No obvious defining character (see characters for Lignophytes & Spermatophytes)

Page 36: The Wonderful World of Green Plant Diversity and Evolution

Female cone with each scalebearing usually two ovules; directly exposed to pollen

Male cones with eachscale bearing two or more microsporangia

Page 37: The Wonderful World of Green Plant Diversity and Evolution

biology.ualberta.edupine pollen

pine microsporangia

male

female

Page 38: The Wonderful World of Green Plant Diversity and Evolution

Fig. 5.7 from Simpson

Page 39: The Wonderful World of Green Plant Diversity and Evolution

Angiosperms• “Dicotyledons”, monocotyledons• Heterosporous (ancestral)• Sporophyte-dominant (ancestral)• Pollen = male gametophyte (ancestral)• Archegonia lost; embryo sac = female

gametophyte; ovules enclosed in carpels (indirect pollination)

• Double fertilization produces zygote + primary endosperm nucleus

Page 40: The Wonderful World of Green Plant Diversity and Evolution

Flower = a short, determinate shoot bearing highlymodified leaves, some of which are fertile (i.e.,bearing either microsporangia or megasporangia),with the megasporangia in carpels

Page 41: The Wonderful World of Green Plant Diversity and Evolution

Animal pollination syndromes

Page 42: The Wonderful World of Green Plant Diversity and Evolution

Wind pollination

Page 43: The Wonderful World of Green Plant Diversity and Evolution

A wide range of fruit types…

Page 44: The Wonderful World of Green Plant Diversity and Evolution

Fig. 5.7 from Simpson

Page 45: The Wonderful World of Green Plant Diversity and Evolution

http://www.mun.ca/biology/scarr/Angiospermae.html

Page 46: The Wonderful World of Green Plant Diversity and Evolution

over 300,000 species of angiosperms

The wonderful world of land plant diversity