In species-rich rainforests of the New World tropics most trees have broad geographic distributions–from Mexico to Bolivia and sometimes to the West Indies. Either they have excellent dispersal abilities, or they established broad ranges prior to the formation of present geographic barriers. In a study featured in American Naturalist, Christopher Dick, Kobinah Abdul-Salim and Eldredge Bermingham address these questions in the first phylogeographic study of a rainforest tree.
The morphology of the study species, Symphonia globulifera (Clusiaceae) is uniform across a natural range that includes the New World tropics and Africa. Symphonia globulifera also has a detailed fossil pollen record, which the authors used to calibrate a molecular clock for DNA sequences obtained from African and Neotropical populations and to estimate when these populations were separated. The study revealed that, although trees from different populations look the same, the evolutionary history of these populations is probably quite distinct.
Although marine dispersal of S. globulifera is considered improbable because it has salt-intolerant seeds, the authors demonstrate that Symphonia expanded into Mesoamerica, the Amazon basin and the West Indies via oceanic currents at least three times. The three major New World clades – found in Mesoamerica, the Amazon basin, and the West Indies – diverged over 15 million years ago, and appear to have been genetically isolated ever since, giving Symphonia globulifera the status of "living fossil".
Christopher Dick | EurekAlert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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