Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA sequences and fossils show that the Proteaceae, a major group of Gondwanaland’s plants, spread by ...

09.08.2007
continental drift and transoceanic dispersal to modern continents

Using DNA sequence data, botanists have shown that the large southern hemisphere plant family Proteaceae lived on the super-continent Gondwanaland almost 120 million years ago. As Gondwanaland broke up, it was originally thought that these plants merely moved with the newly formed continents. But now a new study published in the Journal of Biogeography has shown that, while this is the case for some of these plants, others are far too recent to have lived at the time when the super-continent broke up. They must therefore have dispersed across oceans to reach their current distribution ranges.

Barker et al. apply a technique known as molecular dating to DNA sequences from over 40 representatives of the family from all southern continents. Using carefully selected fossils that are of known age and affinity, the mutation rate of the DNA sequences was calculated, allowing these scientists to provide age estimates for evolutionary events in the family. “Our results show that ancestors of some of the modern Proteaceae must have crossed the Atlantic and Indian Oceans. Thus, in Africa, for example, the spectacular genus Protea is truly Gondwanan, but 250 species from other genera that occur in the ‘fynbos’ vegetation (literally, ‘fine leaved shrubs’) of the highly diverse south-western Cape biodiversity hotspot are much younger, and have Australian relatives” says Nigel Barker of Rhodes University, South Africa.

This new finding is important, as it challenges the dogma that gondwanaland’s biota merely moved in situ with the continents as they broke up. “We have to reconsider the possibility of transoceanic dispersal, as unlikely as it sounds for these plants” says Peter Weston, a researcher at the Royal Botanic Gardens, Sydney, Australia. While this is not the first study to invoke dispersal, it is the first on a major and diverse Gondwanan plant family with complex distribution patterns. These results are not only relevant to botanists. Ornithologists will be intrigued to find that the age of the Embothriinae, a bird-pollinated group of Proteaceae in Australia, coincides with the estimated age of the Honey-eaters, Australian nectar-feeding birds.

... more about:
»DNA »DNA sequence »Proteaceae »continents

Nigel Barker, the first author of the work enthuses “this study is the culmination of 11 years of work. I generated much of the data while working with Peter Weston at the Royal Botanic Gardens in Sydney in 1996. It was only when I met up with Frank Rutschmann in Zurich, who had the expertise on molecular dating, and Hervé Sauquet, a postdoc at the Royal Botanic Gardens, Kew, United Kingdom with an extensive knowledge of the fossil record of the Proteaceae, that it became possible to undertake this rigorous analysis. Sometimes science is about getting the right people with the right skills together in order to make advances”.

Samantha Holford | alfa
Further information:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2699.2007.01749.x

Further reports about: DNA DNA sequence Proteaceae continents

More articles from Life Sciences:

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>