Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

World's largest flower evolved from family of much tinier blooms

15.01.2007
Molecular analysis shows giant rafflesia flower grew 79-fold over millions of years

The plant with the world's largest flower -- typically a full meter across, with a bud the size of a basketball -- evolved from a family of plants whose blossoms are nearly all tiny, botanists write this week in the journal Science.

Their genetic analysis of rafflesia reveals that it is closely related to a family that includes poinsettias, the trees that produce natural rubber, castor oil plants, and the tropical root crop cassava.

The team from Harvard University, Southern Illinois University, the Smithsonian Institution, and the University of Wisconsin was led by Harvard's Charles C. Davis.

... more about:
»Evolutionary »blooms »botanist »rafflesia

"For nearly 200 years rafflesia's lineage has confounded plant scientists," says Davis, an assistant professor of organismic and evolutionary biology in Harvard's Faculty of Arts and Sciences. "As a parasite living inside the tissue of a tropical vine, the plant lacks leaves, shoots, or roots, making it difficult to compare to more conventional plants. Most efforts to place plants in the botanical tree of life in the past 25 years have tracked ancestry using molecular markers in genes governing photosynthesis. Rafflesia is a non-photosynthetic parasite, and those genes have apparently been abandoned, meaning that to determine its lineage we had to look at other parts of the plant's genome."

Davis and his colleagues determined that over an estimated 46 million years, rafflesia's blooms, which now weigh up to 15 lbs., evolved at an accelerated pace. However, after increasing in size by a factor of roughly 79, the plant then reverted to a more sedate evolutionary pace.

This evolutionary spurt is one of the most dramatic size changes ever reported among eukaryotes; if humans were to undergo comparable evolutionary growth, Davis says, an average man would end up some 146 meters tall, roughly the height of the Great Pyramid of Giza.

Because rafflesia lacks the genes most commonly used to trace plant ancestry, the scientists delved deeper into the genome, looking at some 11,500 base pairs of DNA to determine that the giant flower's closest relatives are in the Euphorbiaceae family, many of which have blossoms just a few millimeters in diameter.

"The power of nucleic acid comparisons is revealed as well as ever in this stunning deduction," says noted botanist Peter H. Raven, president of the Missouri Botanical Garden in St. Louis, who was not involved in this research. "The massive increase in flower size is one of the most significant among living organisms, and could never have been deduced by conventional methods."

Found growing on the jungle floor in parts of southeastern Asia, rafflesia is unusual in more than just its flower's size. A parasite, it derives its nutrients from a plant in the grapevine family and lacks leaves, stems, or roots. Even more shocking is the plant's carcass-like appearance: Its blooms are a mottled blood red, reek of decaying flesh, and in some cases even emit heat, much like a recently killed animal. These traits help the flower attract the carrion flies that pollinate it.

"While it's surprising to find this giant plant evolved from a family typified by much smaller blossoms, rafflesia is unusual enough that it's frankly been difficult to imagine it fitting neatly into any plant family," Davis says. "Many botanists had refused to even speculate on where this botanical outlier might fit into the tree of life."

Rafflesia was first discovered in the Sumatran rain forest some 180 years ago by Sir Stamford Raffles, governor of the East India Company's establishments in Sumatra, and Joseph Arnold, a naturalist and physician. Shortly before Arnold died of malaria on that same expedition, he described rafflesia as "the greatest prodigy of the vegetable world," adding, "To tell you the truth, had I been alone, and had there been no witnesses, I should think I would have been fearful of mentioning the dimensions of this flower, so much does it exceed every flower I have ever seen or heard of."

Steve Bradt | EurekAlert!
Further information:
http://www.harvard.edu

Further reports about: Evolutionary blooms botanist rafflesia

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>