Scientists released yesterday the most complete analysis yet of
world's million species of plants are related to one another,
overturning longstanding theories that the first single-celled algae
advanced in size and complexity to become the showy trees and flowers at
pinnacle of plant evolution.
Perhaps most surprising, the
year effort to map the entire family tree for all plants --
than 200 scientists in 12 countries -- has determined
that a rare and
previously unheralded tropical flower is the closest
living relative of the
Earth's first flowering plant.
unexpected discovery uproots both of the leading theories about what
first flower looked like, and apparently solves what Charles Darwin
called the ``abominable mystery'' of how plants made the leap from
green monotony to full floral ebullience. That global makeover
explosion in biological diversity among insects and other
``This is the first comprehensive, coordinated,
large-scale attempt to
reconstruct one of the major branches of life,''
said Brent Mishler, a
professor of integrative biology at the University
of California at Berkeley
and a spokesman for the federally financed
``Deep Green'' project.
The new analysis, presented at the
16th International Botanical Congress
in St. Louis, also comes to the
jarring conclusion that there are at least
three separate plant kingdoms
rather than one, as most high school students
are taught today.
It finds that plants invaded land not directly from the sea, as
scientists had thought, but from fresh water, where they spent
years preparing for the rigors of terrestrial existence.
And it concludes that the many families of green plants on land
descended not from separate evolutionary upstarts but from a
``Eve,'' a close relative of which still lives in pristine
lakes as it did
more than a billion years ago.
intellectual gratification that comes with understanding how
plants are related, the new findings could have practical
Peter Raven, director of the Missouri Botanical Garden, which
the weeklong meeting of 4,000 botanists.
For example, Raven
said, it makes sense for botanists seeking new
medicinal compounds to
focus on plants closely related to those already
known to have
therapeutic properties. But that approach has been hampered by
of an accurate family tree.
worried about accelerating plant extinctions
want to preserve seeds and
other genetic resources from a broad array of
plants. But in order to
decide where to concentrate their efforts, they need
to know which
plants represent the most disparate branches of the botanical
``It's the ability to compare that gives meaning to
biology,'' Raven said.