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from NYTimes: Earliest Flowering Plants

bellow i'm reproducing an article in today's NYTimes re: more development in 
research on the evolution of earliest flowering plants.  hope this  is of 
interest to the list.

tsuh yang chen, nyc, USA



October 29, 1999

Biologists Find Progenitors of Earth's Flowering Plants



After more than a hundred years of arguing, theorizing and frustration, 
evolutionary biologists have at last answered a question so difficult that 
Darwin himself called it the "abominable mystery": how did the world's 
flowering plants, the most diverse and important group of plants on earth, 
first evolve? 

In a highly unusual confluence of discoveries, four teams of researchers 
studying plant DNA have independently and simultaneously come up with the 
same answer to this highly contentious question, deciphering the earliest 
history of flowering plants and identifying the three most ancient groups in 
its family tree. The first of the results to be published appears in Friday's 
issue of the journal Science. 

The three most ancient groups are water lilies, relatives of the spice star 
anise and the oldest of all, a group now represented only by Amborella, an 
unremarkable bush found only on the South Pacific island of New Caledonia. 

Identification of the groups and the drawing of new family trees will allow 
botanists to follow with new precision the evolution of many important 
characteristics of flowering plants, from their defining trait, the flower, 
to their most delicious, the fruit. 

The four teams, involving scientists from many universities in several 
countries, came to identical conclusions, though the results of only one 
team, comprising scientists from Harvard, have been published so far. Between 
them, the teams include most leading researchers using plant DNA comparisons 
to understand the early history of plants. 

"It is the answer," Dr. James Doyle, a paleobotanist at the University of 
California at Davis, said of the identification of the three groups and their 
arrangement on the new family tree of plants. Dr. Doyle was not involved with 
the studies but, like others, he expressed confidence in the results. 

"It's all come to a huge crescendo," he said. 

Dr. Jeff Palmer, molecular evolutionary biologist at Indiana University who 
is a member of one of the four teams, said: "All too often people get results 
that conflict with one another and you're left wondering what the truth is. 
These studies reach the strong conclusion, and it's the same strong 
conclusion. It really is a remarkable event." 

Researchers say that in the past a number of different plants have been 
proposed as the most ancient, among them magnolias, birches, oaks and the 
monocots, a group that includes grasses and lilies. 

"Almost anything you could come up with has been suggested," said Dr. Dick 
Olmstead, a plant evolutionary biologist at the University of Washington who 
is studying the problem with Dr. Sean Graham of the University of Alberta, 
who together formed one of the four teams. 

Based on the new findings, scientists say the progenitor of flowering plants 
-- a group that includes orchids, corn, oaks and cactuses -- was most likely 
woody, possibly shrubby or viney, with a flower bearing an unusual female 
reproductive structure whose parts were glued together by a sticky secretion 
rather than fused into a seamless structure, as they are in modern flowering 

"It's going to really change our view of what the most ancestral type of 
flowering plant was like," Dr. Olmstead said. 

Each team of researchers took slightly different approaches to determining 
the family tree of flowering plants and pinpointing its most ancient groups. 
Dr. Olmstead and Dr. Graham studied a large number of slowly evolving genes. 
Dr. Douglas Soltis and Dr. Pamela Soltis, a husband and wife team at 
Washington State University, and their colleagues looked at fewer genes but 
studied those genes in a wide variety of plants. 

And in research described in Friday's Science article, Dr. Sarah Mathews and 
Dr. Michael Donoghue of Harvard University used a new technique that they 
used to look into the group's history. The researchers studied a gene that 
had duplicated itself into two copies in the earliest flowering plants, 
providing two independent road maps to the evolution of the group -- maps 
that, as the researchers expected, turned out to be very similar. 

The scientists say the new findings do not indicate which nonflowering plant 
sprouted earth's first flower. And, while nearly all researchers have 
enthusiastically accepted the new work, a few have sounded cautionary notes 
over the answer to this question, which has been so problematic in the past. 

For example, Dr. William L. Crepet, a paleobotanist at Cornell University, 
said he would not be shocked if there were some shifting around in these 
early branches of the family tree as studies continued, but he added, "It 
looks pretty good for Amborella right now." 

For biologists seeking a window into the early evolution of flowering plants, 
the new findings are invaluable. Of particular interest is Amborella, the 
bush catapulted from obscurity to botanical stardom. 

Sandra Floyd and Dr. William E. Friedman, plant evolutionary biologists at 
the University of Colorado, are studying the evolution of a part of the seed, 
called the endosperm, that nourishes the plant embryo (or the human who eats 
the seed). 

To fully understand the evolution of this feature, which is unique to 
flowering plants, Ms. Floyd said she and Dr. Friedman were studying the 
endosperm in Amborella, using material from the arboretum at the University 
of California at Santa Cruz, where the only Amborella in the continental 
United States grows. 

"These are the types of things that people have been speculating about for 
decades, centuries," said Dr. Pamela Soltis of Washington State University, 
"and now we can actually address them."