The Evolution of Seed Plants

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The Evolution of Seed Plants Feb. 18 and 23, 2011

• life cycle of the pines
• origin of the seed
• Chapter 30

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1. origin from ancestors similar to charophytes

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Abies amabilis - Oregon
Pinus edulis - New Mexico
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Pinus elliottii - Georgia coast
Pinus ponderosa - Colorado mts.
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Pinus aristata - Colorado
Sequoia sempervirens - Calif.
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Figure 30.9 The life cycle of a pine (Layer 3)
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pollen cones
POLLEN AND SEED CONES OF A PINE
Seed cones
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Pollen Cones on a pine tree
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Figure 30.10x1 Pine Sporangium with spores
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Pine pollen in hand.
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Male gametophyte growing in nucellus
early pollen
dispersed pollen
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The target of the pollen is the ovule -- near the
axis of the seed cone.
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Integument
Male gametophytes
(Megasporangium)
Eggs
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Figure 30.10x3 Pine embryo
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Figure 30.9 The life cycle of a pine (Layer 1)
Integument
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Figure 30.9 The life cycle of a pine (Layer 2)
Integument
Integument
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Figure 30.9 The life cycle of a pine (Layer 3)
Integument
Integument
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The Evolution of Seed Plants

• life cycle of the pines
• origin of the seed

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COAL MEASURE SEQUENCE AT POINT ACONI, CAPE
BRETON ISLAND.
SHALE (MUD STONE) with scattered leaf fossils
COAL
SHALE with rootbearing Fossils in place
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Seed fern fossils provide cluews to the origin of
the seed.
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Seed fern fossils provide cluews to the origin of
the seed.
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Reconstruction of the seed fern Medullosa.
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a coal swamp, dominated by spore-dispersed plants
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Reconstructions of seed fern seeds
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Origin of the Seed. I
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Origin of the Seed. II