Transcript Protist Evolution

Protist Evolution
BIOL 1407
Domain Eukarya is Sister Taxon
to Domain Archaea
Prokaryotes vs. Eukaryotes
Evolution of Cytoskeleton
• Some bacteria have
proteins similar to actin &
tubulin
• Actin = MreB
• Tubulin = FtsZ
•
More info:
•
http://www.palaeos.com/Eukarya/Eukarya.Origins.3.
html
http://www.esrf.eu/UsersAndScience/Publications/Hi
ghlights/2001/life-sciences/LS10.html
•
Endomembrane System
• Endomembrane
system of
eukaryotes:
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–
–
–
Nuclear envelope
ER
Golgi
Vesicles &
vacuoles
• ↑ Surface Area
Evolution of
Endomembrane System
• Some
bacteria:
plasma
membrane
folded to
inside
Evolution of Endomembrane System
Primary Endosymbiosis
• Formed when
host cell engulfs
another
prokaryote
• Mutualistic
relationship
develops
• Become a single
cell
Evidences for Primary Endosymbiosis
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•
•
•
•
•
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Size
Enzymes and transport systems
Binary fission
Circular chromosome
Genome still active
Ribosomes
DNA sequences
Evolution of Mitochondria
• Molecular
evidence
– Alpha
proteobacteria
is sister taxon
to mitochondria
Primary Endosymbiosis
Evolution of Chloroplasts
• Molecular
evidence
– Cyanobacteria
is sister taxon
to chloroplasts
Secondary Endosymbiosis
• Eukaryotic
cell
engulfed by
another
eukaryote
• Evolves into
an organelle
Adaptive Radiation of Eukaryotes
Fossil Evidence
• Earliest body fossils:
2.1 bya
– Fossil cysts
(acritarchs) of
dinoflagellate
ancestors
• Molecular fossils: 2.7
bya
– Sterols
(Acritarch)
The End
Unless otherwise specified, all images in this presentation came from:
Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.