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WILLIAM A. ROTTSCHAEFER 《Biology & philosophy》1997,12(3):369-384
In his recent The Temptation of Evolutionary Ethics, Paul Farber has given a negative assessment of the last one hundred years of attempts in Anglo-American philosophy, beginning with Darwin, to develop an evolutionary ethics. Farber identifies some version of the naturalistic fallacy as one of the central sources for the failures of evolutionary ethics. For this reason, and others, Farber urges that though it has its attraction, evolutionary ethics is a temptation to be resisted. In this discussion I identify three major, historically relevant forms of the naturalistic fallacy, the (1) the deductive, (2) genetic, and (3) open question forms and argue that none of them pose an intrinsic problem for evolutionary ethics. I conclude that on this score at least there is no reason to resist temptation. 相似文献
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NANCY S. LAMONTAGNE DAVID F. JOHNSON WILLIAM B. JAKOBY CHESTER E. HOLMLUND 《The Journal of eukaryotic microbiology》1982,29(3):401-405
ABSTRACT. Dehydrogenase activity with hydroxysteroids has been observed in Tetrahymena furgasoni (formerly T. pyriformis strain W), and the enzyme responsible has been isolated from this organism. The purified dehydrogenase is active with a variety of steroid alcohols at apparent Km values ranging from 0.2 to 4.0 mM. The C-3 hydroxyl of ring A of the steroid nucleus is the preferred position of oxidation. However, a variety of other secondary alcohols are also substrates, with apparent Km values for 2-butanol, 2-pentanol, and cyclohexanol of 880, 1000. and 150 mM, respectively. With both steroidal and nonsteroidal alcohols. NAD is the preferred co-substrate, although low activity with NADP is observed. Evidence is presented that the activity with secondary alcohols, whether steroidal or not, is the property of a single protein species. 相似文献
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WILLIAM W. SANFORD F.L.S. ILESANMI ADANLAWO 《Botanical journal of the Linnean Society. Linnean Society of London》1973,66(4):307-321
The velamen and exodermis of roots of 76 species of epiphytic orchids occurring in West Africa were examined and evaluated for the following characters: number of velamen layers; wall striations and hairs of the velamen; wall thickening and lignification of velamen and exodermal cells; size, and uniformity in shape and size, of velamen and exodermal cells. The term epi-velamen is proposed for the distinctive outermost layer of multi-seriate velamen. High correlation is reported between the number of velamen layers and taxonomic as well as habitat-tolerance groupings, together with lower, but still appreciable, correlation between the other characters evaluated and taxonomic and habitat-tolerance groupings. 相似文献
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WILLIAM W. SANFORD 《Botanical journal of the Linnean Society. Linnean Society of London》1971,64(2):163-181
Induction of flowering in orchids and controlling factors are briefly reviewed and results presented of observations on 121 epiphytic and 22 terrestrial West African orchid species under cultivation in Nigeria, together with field observations and published reports. It is concluded that about 66% of West African epiphytes flower during one fairly consistent period of the year, 21% during two or three periods and 13% over a long and variable period. At least 35% of the epiphytes and perhaps at least 27% of the terrestrials seem directly day-length controlled. Additional species appear indirectly influenced by day-length. Low temperature and temperature fluctuations induce flowering in other species. Moisture influences flowering only in shortening the time required for ontogenetic maturity. Epiphytes at high altitudes bloom earlier than plants in lowlands, and sometimes at different seasons. Possible genetically controlled blooming-time variations are mentioned. 相似文献
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