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| Registros recuperados: 15 | |
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| Schram, Frederick R.. |
| I have long maintained that in the unfolding of exciting lines of research, seldom can one plan how to achieve a cooperative program. “Planned science,” more often than not, is forced science and not particularly productive. Far more significant is the role of serendipity in defining an exciting and innovative line of research, i.e., a truly stimulating cooperation. Fundamental advances simply cannot be planned for; one has to flow with the current. Thus it was that serendipity brought together the research group in Experimental Embryology of Prof. dr. J.A.M. van den Biggelaar at the University of Utrecht, and my own group in Systematics and Zoogeography at the University of Amsterdam. Several years ago I had received a grant proposal to review from the... |
| Tipo: Article / Letter to the editor |
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| Ano: 2002 |
URL: http://www.repository.naturalis.nl/record/534299 |
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| Minelli, Alessandro; Schram, Frederick R.. |
| A new analysis within the framework of developmental genetics provides both raw data and theoretical support to the “old” morphology and suggests a new, more predictive, approach to the concept of homology. We distinguish between “positional homologues” and “structural homologues” as independent components of the more general concept of homology. We discuss some general patterns seen in the anatomy of animals and in their morphogenesis. Slack et al. (1993) advanced the concepts of the “zootype”, a particular spatial pattern of gene expression, and the “phylotype”, a particular stage of embryonic development that expresses the zootype. We build upon these concepts and expand them. This allows us to propose some additional phylotypes (arthrotype, cyclotype,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Homology; Phylotype; Macroevolution; Morphogenesis. |
| Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/504249 |
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| Schram, Frederick R.; Vonk, Ronald. |
| Jan Stock was born in western Amsterdam 22 February 1931, the only child of Jan Hendrik Stock, a bank clerk, and Elisabeth Stock-Knevel. He exhibited an early interest as a child in living things, raising plants on a back balcony of his parents apartment and collecting animals during family excursions to the beaches at Zandvoort. However, it was in his early teens in the Hoogere Burgerschool that his interest in biology blossomed where he achieved perfect scores in natural history on his final examinations. He entered the University of Amsterdam in 1948 to pursue his studies of biology and worked under such figures as Profs. L.F. de Beaufort and H. Engel – his predecessors in the chair of Special Zoology – as well as Profs. J.E.W. Ihle and E.J. Slijper. It... |
| Tipo: Article / Letter to the editor |
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| Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/534383 |
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| Schram, Frederick R.. |
| For anyone interested in the early history and evolution of arthropods, one simply cannot get along without reference to the series of works that have been appearing since the 1970s by Dieter Waloszek and Klaus Müller on the Cambrian Orsten fossils. Of particular importance in this regard is the sequence of exceptional monographs published in Fossils and Strata. This volume is the most recent in that series. The Phosphatocopina were first recognized by Müller (1964) and placed among the ostracodes. With little more than the bivalved shell known at that time, this was understandable. Any small bivalved critters found in the Cambrian were automatically considered to be ostracodes in those days. In this instance, the phosphatocopines were believed to be... |
| Tipo: Article / Letter to the editor |
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| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/534317 |
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| Jenner, Ronald A.; Hof, Cees H.J.; Schram, Frederick R.. |
| The palaeostomatopod crustacean Bairdops beargulchensis Schram & Horner, 1978 (Malacostraca, Hoplocarida) from the Mississippian Bear Gulch Limestone is now seen as a taxonomic composite that arose from the confusion of specimens of two distinct hoplocarid species. These species are herein described as the palaeostomatopod Bairdops beargulchensis Schram & Horner, 1978 and a new species of archaeostomatopod, Tyrannophontes acanthocercus. quite distinct from the Pennsylvanian archaeostomatopod Tyrannophontes acanthocercus is T. theridion from the Essex fauna (Mazon Creek), with which it was originally compared. Bairdops beargulchensis is very similar to the Mississippian palaeostomatopod, B. elegans, from the Scottish Glencartholm fauna. A previously... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Malacostraca; Hoplocarida; Stomatopoda; Phylogeny; Bear Gulch. |
| Ano: 1998 |
URL: http://www.repository.naturalis.nl/record/534339 |
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| Vonk, Ronald; Schram, Frederick R.. |
| The suborder Ingolfiellidea currently consists of 39 named species. An historical overview is presented and phylogenetic and biogeographic analyses are made. The result of the phylogenetic analysis suggests the definition of two new genera within an African freshwater group, namely Paraleleupia n. gen. and Proleleupia n. gen. Re-examination of a supposedly Italian relict species, Metaingolfiella mirabitis, with the aid of SEM techniques reveals a half-fusion of the head region with the first pereionite. The issue of the function of the ‘eyelobe’ is addressed and an explanation presented after examining with SEM such lobes in different species. Furthermore, additional descriptions are given based on the type-material of Metaingolfiella mirabilis,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Ingolfiellidea; Phylogeny; Biogeography; New genera; Paleogeographic maps; Bibliography. |
| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/534291 |
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| Schram, Frederick R.. |
| Review of: History of Insects, edited by A. P. Rasnitsyn and D. L. J. Quicke. Kluwer Academic Publ., Dordrecht, Netherlands, 2002, 517 pp., ISBN 14 0200 026 X In the winter of 1977, I visited the Paleontological Institute of the Academy of Sciences in Moscow. I wanted to study the type specimens of fossil crustaceans, which were housed in the Laboratory of Paleoentomology. I thought that strange at the time, but then there were not many fossil crustaceans known from Russia and guessed that someone had decided that the collection for fossil hexapods was the best place to store the shrimp. It was on that occasion that I first encountered the fossil insect research group under the direction of Prof. Boris Borissevich Rohdendorf. It surprised me to discover... |
| Tipo: Article / Letter to the editor |
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| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/534336 |
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| Schram, Frederick R.. |
| The sub-title of this fascinating volume is “Ontogeny, Morphology, and Evolution.” In its comprehensive approach, it is an example of what can result if one is willing to look at situations differently, to break away from preconceptions, and to ask some new questions that begin with the phrase, “What if ... ?” In this case, what if we throw away the adultocentric view of ontogeny, i.e., directed at the adult organism, and look at ontogeny as embryocentric, a sort of on-going Markov process directed at the next stage and not at some final cause? As Minelli cautions us in the introductory chapter, the “existence of a feedback ... does not imply the existence of a programme.” There are many ways in which to look at nature, and there is value in the... |
| Tipo: Article / Letter to the editor |
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| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/534329 |
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| Schram, Frederick R.. |
| Review of: Systema Porifera, edited by J. N. A. Hooper and R. W. M. van Soest. Kluwer Academic Publ., Dordrecht, Netherlands, 2002, 1708 pp., ISBN 0-306-47260-0 This seems to be a time for the publication of big compendia. One would have thought that in this age of the internet one would be turning to convenient web-sites to find the latest catalogues of data and information about biodiversity of animal groups. Indeed, such do exist, and many of them are remarkably detailed and informative. Nevertheless, there has been a steady stream lately of traditional hardcopy volumes presenting systematic and taxonomic overviews of various groups of animals. This handsome two-volume set is amongst the latest example of these kinds of books to appear. |
| Tipo: Article / Letter to the editor |
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| Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/534318 |
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| Registros recuperados: 15 | |
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