BIO-214 Lab #7: History of Plant Evolution

Order of Plant Evolution

1. Nonvascular

   • Aquatic: Algae

   • Land: Mosses

2. Vascular

   1. No Seeds

      • Ferns

   2. Gymnosperms

      • Ginkgos

      • Conifers

      • Cyacads

   3. Angiosperms

      • Flowering Plants

Geological Eras & Periods

1. Paleozoic

   1. Cambrian: 544 mya

   2. Ordovician: 504 mya

   3. Silurian: 440 mya

   4. Devonian: 410 mya

   5. Carboniferous: 360 mya

   6. Premian: 286 mya

2. Mesozoic

   1. Triassic: 248 mya

   2. Jurassic: 213 mya

   3. Cretaceous: 145 mya

3. Cenozoic

   1. Tertiary: 65 mya

   2. Quatrinary: 1.8 mya

Cambrian Plants

• Nonvascular plants:

  • Aquatic Algae

Ordovician Era Plants

• Nonvascular plants:

  • Aquatic Algae

Silurian Era Plants

• Nonvascular plants:

  • Aquatic Algae

Devonian Era Plants

• Nonvascular plants:

  • Aquatic Aglae

• Vascular Plants:

  • Seedless

    • Ferns

Carboniferous Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

Premian Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

Triassic Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

Jurassic Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

Cretaceous Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

  • Angiosperms

    • Flowering plants

Teriary Era Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

  • Angiosperms

    • Flowering plants

Quatrinary Plants

• Nonvascular plants:

  • Aquatic algae

  • Land Mosses

• Vascular Plants:

  • Seedless

    • Ferns

  • Gymnosperms

    • Conifers

    • Ginkgos

    • Cycads

  • Angiosperms

    • Flowering plants

Cyanobacteria

• Blue-green algae

• Bacteria (no nucleus) that can photosynthesize

Anabaena

• Water organisms that evolved from being unicellular to more complex, multiceullar

• Have specialized cells that help with nitrogen fixation

Types of nonvascular plants

1. Stoneworts/charales

2. Liverworts

3. Horneworts

4. Mosses

Stoneworts/charales

• Colonized the land

• Ancestoral land plant

  • Group of freshwater green algae

Liverworts

• First land plants

• Still need moisture & live clining to rocks in damp enviornments/near streams

Mosses

• First identifiable transport system

  1. Xylem: water transport sys

• Reproduce via spores

  • Encase sex cells to prevent dessication

• Still need to live near water

Hornworts

• Developed the cuticle & stomata

  • Cuticle: waxy coating to prevent water loss

  • Stomata: pores in the cuticle to allow for gas exchange

  • ALL land plants except liverworts have cuticles & stomata

What process led to the first “true” land plants?

Development of a true vascular system

• Allowed for a better transport of water

• Provided structural support for the plant to grow taller

Club mosses

• Adaptations

  1. True leaves with veins

  2. Developed roots as an anchoring system

     • Allowed plants to grow taller

  3. Phloem: Sugar Transport System

     • Roots grow in the dark & need sugars to grow

Horsetails

• Have a hollow stem surrounded by a ring of vascular tissue → and therefore light

• Smaller today than their ancestors

Non-seeded Ferns

• Developed proper, complex leaves

• Reproduce via spores

  • STILL WATER DEPENDENT

Seed Ferns

• NOW EXTINCT ☹

• First to produce seeds (not ferns at all)

• Lived away from water

  • No longer produce spores

What development allowed plants to colonize land AWAY from water?

• Evolution of seeds

• Reproduction is no longer water dependent

• Seeds remain dormant until the right conditions for growth → allow plants better survival chances

Gymosperms

• First seed producing plants

• Seeds develop on the surface of scales or leaves → often modified to form cones

• “Naked seed”

Cycads

• Found in warm climates

• favorite dino food lol

Ginkgo

Plants developed fleshy cones

Conifers

• Produce male & female cones

  • Male cones: contain pollen

  • Female cones: contain the ovules

• Depend on wind for reproduction

Angiosperms

• Flowering plants

• Produce flowers with an ovary in which the seed develops & is protected

• Produce fruit with seeds within

  • Co-evolved with insects

  • Insect pollination gave rise to a huge diversity of flowering plants

Key developments that gave rise to modern plants

1. Xylem: Water Transport

2. Stomata

3. Cuticle

4. Roots

5. Phloem: Sugar Transport

6. Stem

7. Seeds

8. Pollen Tube

   • Pollen lands directly on the ovule to fertilize it

   • Pollen cell developed a tube to move the sperm from the stigma into the ovary for fertilization

9. Flowers