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1.
Development of the animal body plan is controlled by large gene regulatory networks (GRNs), and hence evolution of body plans must depend upon change in the architecture of developmental GRNs. However, these networks are composed of diverse components that evolve at different rates and in different ways. Because of the hierarchical organization of developmental GRNs, some kinds of change affect terminal properties of the body plan such as occur in speciation, whereas others affect major aspects of body plan morphology. A notable feature of the paleontological record of animal evolution is the establishment by the Early "Cambrian of virtually all phylum-level body plans. We identify a class of GRN component, the kernels" of the network, which, because of their developmental role and their particular internal structure, are most impervious to change. Conservation of phyletic body plans may have been due to the retention since pre-Cambrian time of GRN kernels, which underlie development of major body parts. 相似文献
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Olson EN 《Science (New York, N.Y.)》2006,313(5795):1922-1927
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Ahlberg PE 《Science (New York, N.Y.)》2004,305(5691):1715; author reply 1715
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Keeling PJ Archibald JM Fast NM Palmer JD 《Science (New York, N.Y.)》2004,306(5705):2191; author reply 2191
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Bascompte et al. (Reports, 21 April 2006, p. 431) used network asymmetries to explain mathematical conditions necessary for stability in historic models of mutualism. The Lotka-Volterra equations they used artificially created conditions in which some factor, such as asymmetric interaction strengths, is necessary for community coexistence. We show that a more realistic model incorporating nonlinear functional responses requires no such condition and is consistent with their data. 相似文献
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Beacham TD 《Science (New York, N.Y.)》2003,302(5642):59; discussion 59
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Tan et al. (Reports, 25 September 2009, p. 1686) argued that loss of tyrosine residues from proteins in metazoans was driven by positive selection to remove potentially deleterious phosphorylation sites. We challenge this hypothesis, providing evidence that the high guanine-cytosine (GC) content of metazoan genomes was the primary driver in the loss of tyrosine residues. 相似文献
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Kaschube et al. (Reports, 19 November 2010, p. 1113) argue that pinwheel density in three mammalian species follows a universal constant of π as predicted by their orientation-selective suppressive long-range connectivity model. We dispute their conclusions and suggest that a simple brain size-pinwheel density scaling law suffices in predicting the self-organized and disorganized orientation maps from primates to rodents. 相似文献
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Brower AV 《Science (New York, N.Y.)》2004,303(5655):173; author reply 173
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Tatar M 《Science (New York, N.Y.)》2005,307(5710):675; author reply 675
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S Löffler J Körber U Nubbemeyer K Fehsel 《Science (New York, N.Y.)》2012,337(6095):646; author reply 646
Ray et al. (Reports, 29 July 2011, p. 637) assume that clozapine-N4-oxide (CNO) represents a "biologically inert synthetic ligand" that selectively activates the M4 muscarinic receptor-based DREADD (designer receptor exclusively activated by a designer drug). In contrast, due to the redox cycling of CNO with clozapine and to their cell membrane permeability, CNO is biologically active and its conversion products are capable of undermining DREADD effects. 相似文献
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Barbash DA 《Science (New York, N.Y.)》2011,333(6049):1576; author reply 1576
Matute et al. (Reports, 17 September 2010, p. 1518) tested the theory that the number of genes involved in hybrid incompatibility increases faster than linearly. However, the method they used is inappropriate because it detects genes that are haploinsufficient in a hybrid background but that would not contribute to lethality in wild-type hybrids, thus overestimating the frequency of hybrid inviability. 相似文献
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Marx and Uhen (Reports, 19 February 2010, p. 993) suggested that correlated diversity changes in the fossil record of whales and diatoms reflects secular evolutionary signals of underlying ecological drivers. We question the meaning of this association and outline avenues for more complete testing of correlations between productivity and marine consumers through geologic time. 相似文献
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Pearthree PA Spencer JE Faulds JE House PK 《Science (New York, N.Y.)》2008,321(5896):1634; author reply 1634
Polyak et al. (Reports, 7 March 2008, p. 1377) reported speleothem data leading to their inference that the western Grand Canyon incised much earlier than previously thought. This contradicts several lines of published geological knowledge in the region, hinges upon unjustified hydrogeological assumptions, and is based on two anomalous data points for which we offer alternative explanations. 相似文献
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Yu F Hill RS Schaffner SF Sabeti PC Wang ET Mignault AA Ferland RJ Moyzis RK Walsh CA Reich D 《Science (New York, N.Y.)》2007,316(5823):370
Mekel-Bobrov et al. (Reports, 9 September 2005, p. 1720) suggested that ASPM, a gene associated with microcephaly, underwent natural selection within the last 500 to 14,100 years. Their analyses based on comparison with computer simulations indicated that ASPM had an unusual pattern of variation. However, when we compare ASPM empirically to a large number of other loci, its variation is not unusual and does not support selection. 相似文献
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Palanichamy MG Agrawal S Yao YG Kong QP Sun C Khan F Chaudhuri TK Zhang YP 《Science (New York, N.Y.)》2006,311(5760):470; author reply 470
On the basis of mitochondrial DNA sequence analyses, Thangaraj et al. (Brevia, 13 May 2005, p. 996) proposed that Andaman islanders descended from the first humans to migrate out of Africa. We identified mitochondrial DNA from two northeast Indian Rajbanshi individuals that shares three specific mutations with the M31a lineage observed in the Great Andamanese, which suggests that the predecessor of haplogroup M31 originated on the Indian subcontinent. 相似文献