Transcript The “Revised” Tree of Life

Endosymbiosis and
the “Tree of Life”
The Tree of Life
Eukarya
Animals
Fungi
Plants
Archaea
Bacteria
Other bacteria
Proteobacteria
Crenarchaeota
Euryarchaeota
Other single cell
eukaryotes
Endosymbiotic Theory
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Evidence suggests that eukaryotes obtained their
mitochondria and chloroplasts by engulfing bacterial cells.
Eventually, the engulfed bacterium gave up its ability to live
on its own after some of its genes were transferred to the
nucleus of the host cell.
Lynn Margulis
The Revised Tree of Life
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Three domains: Bacteria, Archaea, and
Eukarya
Because lateral gene transfer is thought to
have been common among the earth’s
earliest organisms, the revised tree of life
has some “untreelike” cross-links between
branches.
Animals
BACTERIA
Fungi
Plants
ARCHAEA
Cyanobacteria
Other
bacteria
EUKARYA
Crenarchaeota
Euryarchaeota
Proteobacteria
Algae
Bacteria that gave
rise to chloroplasts
Hyperthermophillic
bacteria
Bacteria that gave
rise to mitochondria
Other
single-cell
eukaryotes