Marc A. Carrasco

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Estimates of paleodiversity patterns through time have relied on datasets that lump taxonomic occurrences from geographic areas of varying size per interval of time. In essence, such estimates assume that the species-area effect, whereby more species are recorded from larger geographic areas, is negligible for fossil data. We tested this assumption by using(More)
We derived species richness curves using three different methods for mammal species recorded in fossil deposits between 30 million and 9 million years old (late Oligocene through late Miocene) for three geographic regions in the USA: the Northwest, northern Rocky Mountains and northern Great Plains. The data were used to examine the relationship between(More)
future Quaternary megafaunal extinctions and implications for the Collateral mammal diversity loss associated with late service Email alerting articles cite this article to receive free e-mail alerts when new here click request Permission this article to seek permission to re-use all or part of here click
Earth has experienced five major extinction events in the past 450 million years. Many scientists suggest we are now witnessing a sixth, driven by human impacts. However, it has been difficult to quantify the real extent of the current extinction episode, either for a given taxonomic group at the continental scale or for the worldwide biota, largely because(More)
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a r t i c l e i n f o It is becoming increasingly important to understand how present diversity patterns compare with past ones, in order to understand the extent of change that present faunas exhibit with respect to past baselines for such parameters as extinction rate and magnitude, ecological structure, and ecosystem function. However, these comparisons(More)
a r t i c l e i n f o Previous work has suggested that tectonically active regions act as speciation pumps for mammals and plant species , but little is known about how fast or widespread tectonism must be in order to directly influence evolution. Here, we use oxygen and hydrogen isotopic data from Miocene sedimentary deposits to characterize the(More)
Cover illustration: Artist's depiction of the living Laotian rodent Laonastes aenigmamus standing upon lacustrine strata containing a well-preserved skeleton of the early Miocene rodent Diatomys shantungensis. Mary Dawson and her colleagues were the first to recognize that Laonastes is a surviving member of the otherwise extinct rodent clade Diatomyidae(More)
This paper traces the influence of F. W. Taylor and H. Fayol in the scientific output of brazilian nursing from 1930 to 1980. The scientific output of brazilian nursing is reviewed, looking for work based upon the Scientific and Classical Schools of Administration. The author executes a bibliographic survey based upon two periodicals: Revista Brasileira de(More)