From evolutionary morphology towards evolutionary ecology

Entsprechend den Frageweisen nach proximater Ursache bzw. ultimater oder historischer Bedingtheit lassen sich Entwicklungs-, Funktions-, Evolutions- und phylogenetische Morphologie unterscheiden. In der Evolutionsmorphologie wird nach der biologischen Rolle und dem Selektionswert für Strukturen gefragt, was sich aus direkter Beobachtung oder Analogievergleich erschließen kann. Ausgehend von detaillierter vergleichender Strukturuntersuchung eröffnet sich damit das Feld der Evolutionsökologie mit dem Ziel der Rekonstruktion historischer Einnischung und Erschließung ökologischer Zonen. Nach Untersuchung der ökologischen Nischen rezenter Arten soll hierbei die jeweilige Ökonische einer Stammart am Gabelpunkt eines zuvor erstellten Cladogramms (Stammart-Nische) rekonstruiert und ihre jeweilige Transformation durch Abänderung, Neubildung oder Auflösung von Synergs – jedenfalls in wichtigen Dimensionen der Organismus-Umwelt-Beziehung – herausgearbeitet werden (Nischenfolge). Beispiel einer Nischenfolge ist bei pilzzüchtenden Ameisen (Attini) die Pilzzucht anfänglich auf Insektenkot als Substrat über Teile von Blütenblättern schließlich zu herausgeschnittenen Laubblättern. Zur Bildung der Nische wird die Interaktion der Organismen mit der Umwelt und die Gemeinschaftsleistung kooperierender Artgenossen besonders betont. Die Artnische kann sich aus verschiedenen, sich meistens zeitlich ablösenden Teilnischen zusammensetzen, denen in der Regel verschiedene Morphen entsprechen. Dies gilt insbesondere für durch Eigenmerkmale gekennzeichnete Larven, deren Metamorphose zum Adultus mit der Verwirklichung einer anderen Teilnische einhergeht. Gravierende Änderungen der Nische in wenigen Evolutionsschritten sind dann möglich, wenn viele Synergs in einem Block zusammengefasst (geclustert) sind (z.B. Wirtspflanzenwechsel bei Phytophagen) oder wenn Teilnischen (von Ontogenesestadien) aufgegeben werden (z.B. durch Viviparie). Verhaltensänderungen für Nischenerweiterung oder -abänderung gehen einem tiefgreifenden Lebensweisewechsel durch Bildung einer neuen ökologischen Zone voraus. Der Zusammenhang von Zonenbildung und „Makroevolution“ wird am Beispiel der Entstehung der Pterygota unter Berücksichtigung von Umweltlizenzen, Präadaptationen, Verhaltensänderungen und evolutiven Anpassungen diskutiert. Die Folge ökologischer Zonen von einer Landwanze hin zu Gerriden auf der Meeresoberfläche wird dargestellt sowie die Zonenfolge von terrestrischen Sackträger-Schmetterlingen zu Raupen, die selbst in stark strömenden Gewässern als Aufwuchsfresser leben. Sechs Punkte des „evolutionsökologischen Programms“ hin zu einer erklärenden Naturgeschichte werden herausgearbeitet.Based on questions about proximate causes and ultimate and historical conditionality for structural features, we can distinguish developmental morphology, functional morphology, evolutionary morphology, and phylogenetic morphology. Evolutionary morphology focuses on the biological roles and the selective values of structures as inferred from direct observation or by analogy. Based on detailed comparative analyses of structures, the field of evolutionary ecology is opened up. The objective of evolutionary ecology is to reconstruct the historical formation of specific ecological niches and the establishment of ecological zones. In-depth investigations of the ecological niches of extant species allow to reconstruct the ecological niche of any stem species at a point of bifurcation in a cladogram. It is further possible to outline the transformation of the ancestral econiche by change, formation or dissolution of synergs which compose the econiche. Thus, the sequence of econiches can be reconstructed, at least in significant dimensions of the relationship between the organism and its environment (synergs). One example is the sequence of econiches in fungus-growing ants (Attini), which initially used insect feces as fungal substrate, then petals, and finally sections of leaves. To realize an econiche, the interactions of organisms with their environment are essential, as well as collaborative activities of conspecifics. The econiche of a species often consists of different, mostly chronological sub-niches, represented by different morphs. Typical examples are larvae (characterized by larval features) and their sub-niches, separated from the adults and their sub-niches by metamorphosis. Substantial evolutionary changes of a niche can happen in a few steps if many synergs are clustered (for instance during the switch to a novel host), or if sub-niches of ontogenetic stages are abandoned (e.g. by evolution of vivipary). Behavioral alterations which broaden or change the econiche precede the dramatic rearrangement of the mode of life during realization of a new ecological zone. The link between the formation of a new ecozone and “macroevolution” is exemplified by the evolution of Pterygota, taking into consideration ecological licenses, preadaptations, alterations of behavior and evolutionary adaptations. The sequence of ecozones during the evolution of a terrestrial true bug towards Gerridae living on the water surface of open oceans is presented, as well as the sequence of ecozones of terrestrial case-building moths towards aquatic caterpillars which feed on algae even in rapidly flowing streams. Six steps of the evolutionary ecology approach towards an explanatory natural history are compiled

Improved source modelling through combined use of InSAR and GPS under consideration of correlated data errors: application to the June 2000 Kleifarvatn earthquake, Iceland

Simultaneous use of multiple independent data sets can improve constraints on earthquake source-model parameters. However, the ways in which data sets have been combined in the past are manifold and usually qualitative. In this paper we present a method to combine geodetic data in source model estimations, which includes characterizing the data errors and estimating realistic model-parameter uncertainties caused by these errors. We demonstrate this method in a case study of the June 2000 Kleifarvatn earthquake, which occurred on Reykjanes Peninsula in Iceland. We begin by showing to what extent additional data can positively influence the source modelling results, by combining both GPS and descending-orbit InSAR data, which were used in two earlier studies of that event, with InSAR data from an ascending orbit. We estimate the data error covariances of the InSAR observations and base the data weights in our model-parameter optimization on the corresponding data variance-covariance matrix. We also derive multiple sets of synthetic data errors from the estimated data covariances that we use to modify the original data to generate numerous data realizations. From these data realizations we estimate the model-parameter uncertainties. We first model the Kleifarvatn earthquake as a simple uniform-slip fault and subsequently as a fault with variable slip and rake. Our fault model matches well with the field observations of coseismic surface ruptures and its near-vertical dip (83°) agrees with the regional faulting style as well as with aftershock locations. The two published source models of the event, on the other hand, both differ from our model as well as differing for one another. These studies, which were based on the descending InSAR data alone (the first study) and on that same data and GPS data (the second study), both neglect correlations in the InSAR data and do not report model-parameter uncertainties. Therefore, to compare these results with our model, we simulate the earlier model estimation set-ups and provide realistic estimates of the model-parameters uncertainties for these cases. We then discuss the significance of the difference between the existing fault models and demonstrate that both the inclusion of additional independent data as well as the covariance-based data weights improve the model-parameter estimatio

Broadband frequency-dependent amplification of seismic waves across Bucharest, Romania

The determination of seismic amplitude amplification is a fundamental contribution to seismic hazard assessment. While often only high-frequency amplitude variations (>1Hz) are taken into account, we analyse broadband waveforms from 0.14 to 8.6Hz using a temporary network of 32 stations in and around the earthquake-prone city of Bucharest. Spectral amplitudes are calculated with an adaptive multiple-taper approach. Across our network (aperture 25km×25km), we find a systematic northwest/southeast-oriented structural influence on teleseismic P-wave amplitudes from 0.14 to 0.86Hz that can be explained by constructive interference in the dipping Cenozoic sedimentary layers. For higher frequencies (1.4-8.75Hz), more local site effects prevail and can be correlated partly among neighbouring stations. The transition between systematic and localised amplitude variations occurs at about 1H

Source model for the 1997 Zirkuh earthquake (MW: 7.2) in Iran derived from JERS and ERS InSAR observations

We present the first detailed source model of the 1997 M7.2 Zirkuh earthquake that ruptured the entire Abiz fault in East Iran producing a 125 km long, bended and segmented fault trace. Using SAR data from the ERS and JERS-1 satellites we first determined a multisegment fault model for this predominately strike-slip earthquake by estimating fault-segment dip, slip, and rake values using an evolutionary optimization algorithm. We then inverted the InSAR data for variable slip and rake in more detail along the multisegment fault plane. We complement our optimization with importance sampling of the model parameter space to ensure that the derived optimum model has a high likelihood, to detect correlations or trade-offs between model parameters, and to image the model resolution. Our results are in an agreement with field observations showing that this predominantly strike-slip earthquake had a clear change in style of faulting along its rupture. In the north we find that thrust faulting on a westerly dipping fault is accompanied with the strike-slip that changes to thrust faulting on an eastward dipping fault plane in the south. The centre part of the fault is vertical and has almost pure dextral strike-slip. The heterogeneous fault slip distribution shows two regions of low slip near significant fault step-overs of the Abiz fault and therefore these fault complexities appear to reduce the fault slip. Furthermore, shallow fault slip is generally reduced with respect to slip at depth. This shallow slip deficit varies along the Zirkuh fault from a small deficit in the North to a much larger deficit along the central part of the fault, a variation that is possibly related to different interseismic repose time

Holocene Vegetation and Land Use History in the Northern Vosges (France)

A radiocarbon-dated peat profile from Rond Pertuis supérieure mire in the uplands of the Northern Vosges is studied using palynological methods. The profile dates from the middle Atlantic period (4500–3100 B.C.) to recent times. During the middle of the Atlantic period an oak forest rich in pine covered the Northern Vosges. Fir and beech immigrated at the end of the Atlantic leading to the decline of oak and pine in the forest. This also marked the onset of decisive human influence on the development of the terrestrial vegetation. Five land use phases were detected, the first one at the end of the Neolithic period (~4000–2200 B.C.). Subsequently, continuous land use is evident from the Bronze Age (2200–800 B.C.) up to now. In the late Middle Ages (A.D. 900–1500) and the early Modern Era (since A.D. 1500), the woodlands were completely altered by human activities. During the 19th century modern forestry introduced spruce into the investigated area in the Northern Vosges. Spruce afforestation then accelerated in the middle of the 20th century.researc

Building on experience

The LIBER Architecture Group reflects on experience of European library building projects from the past twenty years in order to plan the next generation of library buildings. This documentation of recent library building projects accompanies the 14th Seminar of the LIBER Architecture Group, taking place in Budapest and Debrecen (Hungary) 8–12 of April 2008. Most described projects refer to scientific research libraries, however readers will find examples of an archive or public libraries in Amsterdam and Antwerp. Libraries nowadays are spaces to house information resources (and multimedia) but as well places for learning and communication. Recent design of research libraries takes this new usage into account. Therefore examples of »Learning Resource Centers« supporting students during their studies are enclosed

Caenorhabditis monodelphis sp. n.: defining 1 the stem morphology 2 and genomics of the genus Caenorhabditis

Background: The genus Caenorhabditis has been central to our understanding of metazoan biology. The best-known species, Caenorhabditis elegans, is but one member of a genus with around 50 known species, and knowledge of these species will place the singular example of C. elegans in a rich phylogenetic context. How did the model come to be as it is today, and what are the dynamics of change in the genus? Results: As part of this effort to “put C. elegans in its place”, we here describe the morphology and genome of Caenorhabditis monodelphis sp. n., previously known as Caenorhabditis sp. 1. Like many other Caenorhabditis, C. monodelphis sp. n. has a phoretic association with a transport host, in this case with the fungivorous beetle Cis castaneus. Using genomic data, we place C. monodelphis sp. n. as sister to all other Caenorhabditis for which genome data are available. Using this genome phylogeny, we reconstruct the stemspecies morphological pattern of Caenorhabditis. Conclusions: With the morphological and genomic description of C. monodelphis sp. n., another key species for evolutionary and developmental studies within Caenorhabditis becomes available. The most important characters are its early diverging position, unique morphology for the genus and its similarities with the hypothetical ancestor of Caenorhabditis