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Seminar Detail
The Ring of Life Provides Evidence for a Genome Fusion Origin of Eukaryotes
Presenter: Maria Rivera
December 7, 2004 02:30 PM Pacific
The Tree of Life representing the connections among all organisms has
become
an icon of evolutionary biology. But recent analyses of completely
sequenced
genomes and the discovery that horizontal gene transfer (HGT) has
significantly shaped microbial evolution have challenged the concept of
the
Tree of Life. We have determined the general outline of the tree using
complete genome data from representative prokaryotes and eukaryotes and
using a new genome analysis method that makes it possible to
reconstruct
ancient genome fusions and phylogenetic trees even in the presence of
HGT.
Our analyses indicate that the eukaryotic genome resulted from a fusion
of
two diverse prokaryotic genomes, and therefore at the deepest levels
linking
prokaryotes and eukaryotes, the tree of life is actually a ring of
life. One
fusion partner branches from deep within an ancient photosynthetic
group,
and the other is related to the archaeal prokaryotes. The eubacterial
organism is either a proteobacterium, or a member of a larger
photosynthetic
group that includes the Cyanobacteria and the Proteobacteria.
Participation Instructions
http://nai.arc.nasa.gov/seminars/instructions.cfm
December 21, 2007
