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 Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>