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971.
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Lambrechts D Storkebaum E Morimoto M Del-Favero J Desmet F Marklund SL Wyns S Thijs V Andersson J van Marion I Al-Chalabi A Bornes S Musson R Hansen V Beckman L Adolfsson R Pall HS Prats H Vermeire S Rutgeerts P Katayama S Awata T Leigh N Lang-Lazdunski L Dewerchin M Shaw C Moons L Vlietinck R Morrison KE Robberecht W Van Broeckhoven C Collen D Andersen PM Carmeliet P 《Nature genetics》2003,34(4):383-394
973.
Past discoveries usually become aggrandized in retrospect, especially at jubilee celebrations, and the double helix is no exception. The historical record reveals a muted response by the scientific community to the proposal of this structure in 1953. Indeed, it was only when the outlines appeared of a mechanism for DNA's involvement in protein synthesis that the biochemical community began to take a serious interest in the structure. 相似文献
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975.
The long-term carbon cycle operates over millions of years and involves the exchange of carbon between rocks and the Earth's surface. There are many complex feedback pathways between carbon burial, nutrient cycling, atmospheric carbon dioxide and oxygen, and climate. New calculations of carbon fluxes during the Phanerozoic eon (the past 550 million years) illustrate how the long-term carbon cycle has affected the burial of organic matter and fossil-fuel formation, as well as the evolution of atmospheric composition. 相似文献
976.
Hillier LW Fulton RS Fulton LA Graves TA Pepin KH Wagner-McPherson C Layman D Maas J Jaeger S Walker R Wylie K Sekhon M Becker MC O'Laughlin MD Schaller ME Fewell GA Delehaunty KD Miner TL Nash WE Cordes M Du H Sun H Edwards J Bradshaw-Cordum H Ali J Andrews S Isak A Vanbrunt A Nguyen C Du F Lamar B Courtney L Kalicki J Ozersky P Bielicki L Scott K Holmes A Harkins R Harris A Strong CM Hou S Tomlinson C Dauphin-Kohlberg S Kozlowicz-Reilly A Leonard S Rohlfing T Rock SM Tin-Wollam AM Abbott A 《Nature》2003,424(6945):157-164
977.
A growing body of empirical and theoretical work supports the plausibility of sympatric speciation, but there remain few examples in which all the essential components of the process are well understood. The African indigobirds Vidua spp. are host-specific brood parasites. Indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts. As adults, male indigobirds mimic host song, whereas females use these songs to choose both their mates and the nests they parasitize. These behavioural mechanisms promote the cohesion of indigobird populations associated with a given host species, and provide a mechanism for reproductive isolation after a new host is colonized. Here we show that all indigobird species are similar genetically, but are significantly differentiated in both mitochondrial haplotype and nuclear allele frequencies. These data support a model of recent sympatric speciation. In contrast to the cuckoo Cuculus canorus, in which only female lineages are faithful to specific hosts, host switches have led to speciation in indigobirds because both males and females imprint on their hosts. 相似文献
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