Announcements
Urban Forestry project continues!!!
Discussion on reading.
Reading
Natural shattering of seed in rice.
Genes of large effect vs. many genes of small effect
QTL analysis – what is it?
Crossing studies –
Regulation of abscission very important to plants
Conservation Biology
What do you think are the most
important questions?
How can the many challenges
we face be resolved?
Plant diversity
Will start following the book much more closely.
Would be useful to bring your books to class.
Chapter 7 for today's lecture
Evolution of plant diversity
Endosymbiosis has evolved several times, including
several separate events creating 'chloroplasts'
Figure 7.1
Figure 7.2
Algae
Red Algae (Rhodopytes)
Brown Algae (Phaeophytes)
Diatoms (Bacillariophytes)
Dinoflagellates
Chlorophytes
– Chara
Red Algae
Red Algae
Typically in deep water
Often 'crustose'
Quite poorly known with very complicated life
cycles
Brown Algae
Brown Algae
Kelp forests
'Plant-like' growth forms
Middle depth and often have organs that allow
them to float.
Diatoms
Diatoms
Abundant and diverse in both marine and
freshwater environments
Must go through sexual reproduction to restore
size because of morphology.
Diatomaceous earth – an effective way to get
rid of a flea infestation.
Dinoflagellates
Dinoflagellates
Unique morphology with two flagellae located in
grooves.
Form important symbioses with reefs, sponges,
and squids – zooxanthellae.
Diatomaceous earth – an effective way to get
rid of a flea infestation.
Chara - “muskgrass”
A likely ancestor of all land plants
Algae as biofuels.
Many of the major players in the energy
industry are moving away from this idea
though.
Craig Venter has a team working on it.
Evolution of plant diversity
Figure 7.6
Invasion of land
“Bryophytes”?
Liverworts, Hornworts, and Mosses
Liverworts
Liverworts - Marchantia
Thallus – flattened body
Hornworts
Hornworts
Evolution of plant diversity
Figure 7.8
Tracheophytes
Lycophytes
Monilophytes – Psilotum, Ophioglossus, Equisetum
Algaophyton
Lycophytes – Lepidodendron
Lycophytes - Selaginella
Lycophytes - Lycopodium
Equisetum