Researchers map 'super-tree' of flowering plants, solving Darwin’s "abominable mystery"

Joint Press Release
The Royal Botanic Gardens, Kew and Imperial College London

For immediate use
Thursday 26 February 2004

The secret of how flowering plants evolved into one of the Earth's most dominant and diverse groups of organisms is revealed in study led by researchers from the Royal Botanic Gardens, Kew and Imperial College London.

Described by Charles Darwin as an "abominable mystery", the team publish the first complete evolutionary 'super-tree' of relationships among all families of flowering plants in current edition of the Proceedings of the National Academy of Science.

Using a combination of DNA sequence data and statistical techniques for analysing biodiversity, the team concludes that Darwin's suspicion that there is not a simple explanation for the large biodiversity of flowering plants was correct.

Dr Tim Barraclough of Imperial's Department of Biological Sciences and the Royal Botanic Gardens, Kew, says:

"The idea that key evolutionary innovations drive an organism's ability to diversify has been popular with evolutionary biologists for the past 10 years or so. But there's a growing consensus that pinning the success of any group on a single innovation, such as insect fertilisation in the case of flowering plants, is too simplistic."

"Instead, the diversity of flowering plant families is the result of interaction between existing biological traits and the environment in which the plant grows. Effectively biodiversity depends on being the right plant in the right place at the right time."

"For example, grasses appear to be very successful because they have a suite of traits that allows them to thrive in cooler and drier environments. Their form of growth also makes them resistant to fire. But the same traits would not confer abundance and diversity in warmer, wetter environments."

In a letter to Joseph Hooker, Kew's first Director, in 1879, Darwin outlined his "abominable mystery" of flowering plants' rapid diversification. Darwin described his own efforts to identify a single cause as "wretchedly poor".

Subsequent attempts to understand this diversity have been revolutionized by the recent advent of molecular phylogenetics, which uses DNA sequence analysis to map evolutionary relationships. Using this technique, the team were able to compile the wealth of data from over 40 previous large-scale DNA studies on flowering plants into one super-tree.

"Even a decade ago, researchers said it was impossible to build a complete tree of flowering plant families. But recent advances in molecular phylogenetics have heralded a new era in analysing biodiversity," explains Dr Vincent Savolainen of the Royal Botanic Gardens, Kew.

"Our examination of the top 10 major shifts in diversification, which include the grass family and the pea family, indicates they cannot easily be attributed to the action of a few key innovations."

Dr Savolainen added: "The new super-tree will be a unique resource for future studies on plant diversity, ranging from biodiversity, gene evolution and ecological studies. It represents a major step towards the 'Tree of Life', an international effort to recover the evolutionary relationships of all 1.5 million known species on Earth."

Dr Tim Barraclough and Professor Mark Chase are Royal Society University Research Fellows.

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For further information please contact:

Hannah Rogers
Kew Gardens Press Office
Tel: +44 (0)20 8332 5607

Judith H Moore
Imperial College London Press Office
Tel: +44 (0)20 7594 6702
Mobile: +44 (0)7803 886 248
E-mail:j.h.moore@imperial.ac.uk

Notes to Editors

The full paper, 'Darwin's abominable mystery: insights from a supertree of the angiosperms' can be found on the Proceedings of the National Academy of Sciences, USA website at: www.pnas.org/cgi/reprint/0308127100v1

The authors of the study are Prof Mark Chase and Dr Vincent Savolainen at the Royal Botanic Gardens, Kew; Dr Timothy Barraclough and Dr Jonathan Davies, Imperial College London and the Royal Botanic Gardens, Kew; Profs Pamela and Douglas Soltis at the Florida Museum of Natural History, Department of Botany and Genetics Institute, University of Florida. Dr Barraclough is a Royal Society University Research Fellow.

Darwin's letter to Joseph Hooker on 22 July 1879 can be found at:
onlinebooks.library.upenn.edu

The Tree of Life is an international effort to recover the evolutionary relationships of all 1.5 million known species on Earth. Its aim is to benefit biodiversity sciences, medicine and ecology. The project has already received funding from the US National Science Foundation, the European Science Foundation and has attracted the attention of the European Commission for possible funding under their framework VI for Research and Technological Development. Kew and Imperial have so far co-ordinated the European participation.

Further details can be accessed at:eoi.cordis.lu/dsp_details.cfm?ID=31692

About the Royal Botanic Gardens, Kew The Royal Botanic Gardens, Kew is a world famous scientific organisation, internationally respected for its outstanding living collection of plants, herbarium and scientific facilities, as well as its scientific expertise in plant diversity, conservation and sustainable development in the UK and around the world. Last year UNESCO awarded it with World Heritage Site Status.

About Imperial College London Consistently rated in the top three UK university institutions, Imperial College London is a world leading science-based university whose reputation for excellence in teaching and research attracts students (10,000) and staff (5,000) of the highest international quality.Innovative research at the College explores the interface between science, medicine, engineering and management and delivers practical solutions that enhance the quality of life and the environment - underpinned by a dynamic enterprise culture.