Yearbook 2005

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Trade-offs with immunity can theoretically enforce honesty on sexual signals through testosterone, that stimulates sexual traits but also suppresses immunity, and/or carotenoids, that can be used in ornaments or support immune functions. Recently, researchers at the Max Planck Institute for Ornithology found evidence for such trade-offs in male mallards. more
Using the human genome sequence, the just published chimpanzee genome sequence, and measured expression levels of genes in several different tissues, the Max Planck Institute for Evolutionary Anthropology has been studying the evolution of mRNA expression in these closely related species. The data indicates that most of the thousands of observed changes in gene expression have not been selected due to beneficial effects. Selection against deleterious effects shows a strong pattern. Curiously, it seems that tissues differ in the level that they are affected by mutations: thus liver is least constrained, and allows most changes, whereas brain allows least. We also see indications that more changes in gene expression occurred in brain during the evolution of humans than occurred during the evolution of chimpanzees since both of them diverged from their last common ancestor. more
In the early days after the disintegration of the Soviet Union many observers expected violent conflicts to shatter the region as people saw themselves faced with radically decaying living standards and highly artificial political boundaries. Studies of the Max Planck Institute for Social Anthropology challenge this view. The construction of ethnic and national identity among two ethnic groups in Central Asia, the Uzbeks and the Kazaks, show that this relationship may better be understood as a dialectical process in which credit has to be given to historical parameters and social configurations to achieve plausibility and legitimacy. more
After decades of Soviet militant secularism religion re-emerges in the public. It is often assumed that religious revival in Central Asia was an effect of the spiritual or ideological vacuum that accompanied the Soviet collapse. Research at the Max Planck Institute for Social Anthropology suggests that the thriving of “religious nationalism” in the 1990s presented in many ways a continuation of Soviet ideas. However, the failures of transition made these “national” religions increasingly vulnerable to religious groups that defined themselves along supranational lines. The successes of the latter provide new challenges to local ideas about the relation between religion and culture. more

„Dead“ Star generates Cosmic Firework

Max Planck Institute for Astronomy Birkmann, Stephan M.; Quanz, Sascha P.; Krause, Oliver
Very massive stars terminate their short but intensive life with a powerful explosion - a Supernova. The energies set free are enormous making such explosions bright enough that they may outshine a whole galaxy for a short time. An expanding shell of dust and gas surrounding a neutron star remains, one could call the skeleton of the exploded star. A team of astronomers at the Max Planck Institute for Astronomy in Heidelberg and in the USA has found evidence, with the help of the space telescope SPITZER, that the exploded star responsible for the Supernova Cassiopeia A is still extremely active even 325 years after its death. more
Abstract In order to solve the puzzle of the origin of the Galactic ridge X-ray mission (GXRE), its spatial distribution was studied in detail with the RXTE observatory. The obtained X-ray map is very similar to the near-infrared map of the Galactic disk and bulge, which implies that the GRXE closely traces the stellar population of the Galaxy. In the second part of this study RXTE and ROSAT observations were used to evaluate the total volume emissivity of faint X-ray sources in the Solar neighborhood. Based on this estimate it was shown that the bulk of the GRXE is likely a superposition of emission from thousands of cataclysmic variables and millions of coronally active stars. more
Abstract Using a catalog of more than 80000 galaxies with active nuclei, drawn from the Sloan Digital Sky Survey, a team from the MPI for Astrophysics and from Johns Hopkins University has studied the connection between the growth of supermassive black holes at the centers of galaxies and of their host galaxies. Most of the black hole growth today is occurring in relatively low-mass black holes (comparable to the one in the center of our Milky Way), whereas the main epoch of growth of the most massive black holes dates back much earlier. They also find that those galaxies in which the central black hole is currently growing have recently formed stars -- a fact that highlights how the mass of the black hole is tightly linked with the stellar mass of its host. more
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