Comparative studies of leaf evolution in the California Chaparral
In an article published in the May 2004 issue of The American Naturalist, David D. Ackerly (Stanford University) compares the evolution of twelve lineages of the California Chaparral.
Which came first--trait or environment? This question lies at the heart of the study of adaptation by natural selection. In Mediterranean-type climates, many woody plants have small, tough, evergreen leaves (dubbed sclerophylls) which allow them to photosynthesize during the cool wet winters and survive the hot summer dry season. This paper presents the first comparative test of alternative hypotheses to explain these shared features. Did these traits evolve independently in different lineages, in response to the unique Mediterranean-type climate? Alternatively, did the traits evolve first in response to other factors, subsequently promoting the success of these lineages when summer drought conditions arose in the past few million years? Twelve independent plant lineages of the California chaparral were examined, using comparative methods that combine new phylogenetic information and statistical techniques. Only four of the twelve lineages showed the pattern expected if the leaves had evolved to suit the Mediterranean-type climate. In the other cases, the leaf traits appear to be ancestral characteristics of these lineages that predate the climatic conditions. These results, together with biogeographic and paleobotanical information, highlight the importance of ecological processes in concert with adaptive evolution in shaping the form
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
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13.06.2017 | Event News
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