This work has nicely sorted out
the genome tree for plants and resolved a number of issues and provides
confidence in the sequence established.
It will now be easier to go after targets worth chasing.
There is still much that needs to
be done to decode the genome and this will keep folks busy for a long
time. When we are finished though, it is
clear that we will be able to synthesize just about anything we want to see.
Those who read my blog regularly
are aware that I have been developing the working conjecture that humanity
originally arose to modernism some 40,000 thousand years ago and chose to
vacate Earth temporarily around 15,000 years ago. During this time they accomplished every thing
we imagine to accomplish today. This
means that it is plausible that they created a range of new animals and plants
that were then introduced into appropriate habitats. An obvious example is the cheetah with its
coincidental 40,000 bottleneck and its combined dog and cat DNA package. There must be many others to be winkled out if this conjecture
holds true.
Beyond that our agricultural crop
kit from 10,000 years ago were all nicely engineered with doubled up genes to
provide large grains in virtually all six initial centers of agriculture. This is all more plausible (the facts
themselves can not be evaded and beg any simple explanation) if one has active
support from scientific man.
Once again we are on the verge of
repeating all the necessary mythology needed to accomplish what was already
done for us and once we do this it will become obvious that this is what did
happen, or at the least we will be able to test the conjecture to death.
Genome tree of life is largest yet for seed plants
by Staff Writers
This is a phylogenomic reconstruction of the evolutionary
diversification of seed plants. Credit: E.K. Lee et al.
Scientists at the American Museum of Natural History, Cold
Spring Harbor
Laboratory, The New York Botanical Garden , and New York University
have created the largest genome-based tree of life for
seed plants to date. Their findings, published in the journal PLoS Genetics,
plot the evolutionary relationships of 150 different species of plants based on
advanced genome-wide analysis of gene structure and function.
This new approach, called "functional phylogenomics," allows
scientists to reconstruct the pattern of events that led to the vast number of
plant species and could help identify genes used to improve seed quality for
agriculture.
"Ever since Darwin first described the 'abominable mystery' behind
the rapid explosion of flowering plants in
the fossil record, evolutionary biologists have been trying to understand the
genetic and genomic basis of the astounding diversity of plant species,"
said Rob DeSalle, a corresponding author on the paper and a curator in the
Museum's Division of Invertebrate Zoology who conducts research at the Sackler
Institute for Comparative Genomics.
"Having the architecture of this plant tree of life allows us to
start to decipher some of the interesting aspects of evolutionary innovations
that have occurred in this group."
The research, performed by members of the New York Plant Genomics Consortium, was
funded by the National Science Foundation (NSF) Plant Genome Program to
identify the genes that caused the evolution of seeds, a trait of important
economic interest.
The group selected 150 representative species from all of the
major seedplant groups
to include in the study. The species span from the flowering variety-peanuts
and dandelions, for example-to non-flowering cone plants like spruce and pine.
The sequences of the plants' genomes-all of the biological information
needed to build and maintain an organism, encoded in DNA-were either culled
from pre-existing databases or generated, in the field and at The New York
Botanical Garden in the Bronx, from live specimens.
With new algorithms developed at the Museum and NYU and the processing
power of supercomputers at Cold Spring Harbor Laboratory and overseas, the
sequences-nearly 23,000 sets of genes (specific sections of DNA that code for
certain proteins)-were grouped, ordered, and organized in a tree according to
their evolutionary relationships.
Algorithms that determine similarities of biological processes were
used to identify the genes underlying species diversity.
"Previously, phylogenetic trees were
constructed from standard sets of genes and were used to identify the
relationships of species," said Gloria Coruzzi, a professor in New York
University's Center for Genomics and Systems Biology and the principal
investigator of the NSF grant.
"In our novel approach, we create the phylogeny based on all the
genes in a genome, and then use the phylogeny to identify which genes provide
positive support for the divergence of species."
The results support major hypotheses about evolutionary relationships
in seed plants.
The most interesting finding is that gnetophytes, a group that
consists mostly of shrubs and
woody vines, are the most primitive living non-flowering seed plants-present
since the late Mesozoic era, the "age of dinosaurs." They are
situated at the base of the evolutionary tree of seed plants.
"This study resolves the long-standing problem of producing an
unequivocal evolutionary tree of the seed plants," said Dennis Stevenson,
vice president for laboratory research at The New York Botanical Garden .
"We can then use this information to determine when and where
important adaptations occur and how they relate to plant diversification. We
also can examine the evolution of such features as drought tolerance, disease
resistance, or crop yields that sustain human life through improved
agriculture."
In addition, the researchers were able to make predictions about genes
that caused the evolution of important plant characteristics. One such
evolutionary signal is RNA interference, a process that cells use to turn down
or silence the activity of specific genes.
Based on their new phylogenomic maps, the researchers believe that RNA
interference played a large role in the separation of monocots-plants that have
a single seed leaf, including orchids, rice, and sugar cane-from other
flowering plants. Even more surprising, RNA interference also played a major
role in the emergence of flowering plants themselves.
"Genes required for the production of small RNA in seeds were at
the very top of the list of genes responsible for the evolution of flowering
plants from cone plants," said Rob Martienssen, a professor at Cold Spring
Harbor Laboratory.
"In collaboration with colleagues from LANGEBIO [Laboratorio
Nacional de Genomica para la Biodiversidad] in Mexico last year, we found that
these same genes control maternal reproduction, providing remarkable insight
into the evolution of reproductive strategy in flowering plants."
The data and software resources generated by the researchers are
publicly available and will allow other comparative genomic researchers to
exploit plant diversity to identify genes associated with a trait of interest
or agronomic value. These studies could have implications for improving the
quality of seeds and, in turn, agricultural products ranging from food to
clothing.
In addition, the phylogenomic approach used in this study could be
applied to other groups of organisms to further explore how species originated,
expanded, and diversified.
"The collaboration among the institutions involved here is a great
example of how modern science works,"
said Sergios-Orestis Kolokotronis, a term assistant professor at Columbia
University's Barnard College and a research associate at the Museum's Sackler
Institute. "Each of the four institutions involved has its own strengths
and these strengths were nicely interwoven to produce a novel vision of plant
evolution."
Other authors include Ernest Lee, American Museum of Natural History;
Angelica Cibrian-Jaramillo, American Museum of Natural History, The New York
Botanical Garden, and New York University - currently at the Laboratorio
Nacional de Genomica para la Biodiversidad, Mexico; Manpreet Katari, New York
University; Alexandros Stamatakis, Technical University Munich - currently at
Heidelberg Institute for Theoretical Studies; Michael Ott, Technical University
Munich; Joanna Chiu, University of California, Davis; Damon Little, The New
York Botanical Garden; and W. Richard McCombie, Cold Spring Harbor Laboratory.
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