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1.
Darwin was a teleologist 总被引:3,自引:0,他引:3
James G. Lennox 《Biology & philosophy》1993,8(4):409-421
It is often claimed that one of Darwin's chief accomplishments was to provide biology with a non-teleological explanation of adaptation. A number of Darwin's closest associates, however, and Darwin himself, did not see it that way. In order to assess whether Darwin's version of evolutionary theory does or does not employ teleological explanation, two of his botanical studies are examined. The result of this examination is that Darwin sees selection explanations of adaptations as teleological explanations. The confusion in the nineteenth century about Darwin's attitude to teleology is argued to be a result of Darwin's teleological explanations not conforming to either of the dominant philosophical justifications of teleology at that time. Darwin's explanatory practices conform well, however, to recent defenses of the teleological character of selection explanations.I would like to thank John Beatty, David Hull and one of this journal's readers for constructive comments on an earlier draft of this paper. 相似文献
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呼和浩特地区蔬菜污染现状综合评价 总被引:1,自引:0,他引:1
呼和浩特地区蔬菜污染现状综合评价杨在中(内蒙古大学,呼和浩特010021)黄雅琴(内蒙古环境监测中心站,呼和浩特010010)ComprehensiveassessmentonpollutionstatusofvegetablesinHuhehot.... 相似文献
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Inclusion of IAA in the vase water had little effect on leaf yellowing in cut flowering branches of Alstroemeria pelegrina L. while kinetin delayed leaf yellowing at 10-4M (continuous treatment). Chlorophyll was effectively retained by 10-7M gibberellic acid (GA) in the vase water or by a 20h pulse at 5°C with 10-5/10-4M GA. After 16h of 14C-GA, uptake at 20°C relatively high levels of 14C were found in leaves and low levels in stems and flowers. After this treatment about half of the 14C-GA, in leaves was metabolized into unknown compounds.
Corrigendum. Owing to an error in the proofreading process, the article was published incorrectly. The article as it should have been published is presented here. 相似文献
4.
Goldfish (Carassius auratus) and bluegill sunfish (Lepomis macrochirus) were placed in aquaria where their locomotor activity was monitored by photocells, and tested at various acclimation temperatures over a range encompassing their final thermal preferenda. Activity was pooled over 24-hour periods to eliminate any circadian rhythm effects. Both species exhibited an activity well of reduced locomotor activity in the region of the final preferendum. Goldfish, tested either singly or in groups of 2–5 individuals, exhibited a social-interaction effect which became more pronounced at higher temperatures. These results are discussed in relation to a thermokinetic interpretation of thermo-regulatory behavior in fishes, and to the correspondence between thermal preferenda and thermal optima. 相似文献
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保鲜剂及冷藏对鹤望兰切花瓶插品质的影响 总被引:2,自引:0,他引:2
本文探讨不同保鲜剂、预处理液及冷藏时间对鹤望兰切花瓶插寿命和观赏品质的影响。结果表明,供试的8组瓶插保鲜液中,以配方5% S+300 mg/L 8-HQC+100 mg/L CA+150 mg/L STS+100 mg/L CoCl2+25 mg/L EDTA-Na保鲜效果最佳,切花瓶插寿命(23.5 d)比CK延长15.2 d,小花开放率(56.1%)比CK提高1.19倍。供试的5组冷藏预处理液中,以10% S+300 mg/L 8-HQC+75 mg/L KH2PO4·3H2O效果最佳,切花经过2~3周8~10℃冷藏后,瓶插寿命(13.7 d)比CK延长7.9 d,小花开放率(43.6%)比CK提高98.2%;该处理组鹤望兰切花的适宜冷藏时间可延长为3周。 相似文献
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以切花菊'神马'叶片为外植体,采用根癌农杆菌介导法将长筒石蒜凝集素基因LLA导入菊花.结果表明,'神马'叶片对潮霉素(Hyg)十分敏感,叶盘再生筛选以8~10 mg·L~(-1)为宜,生根筛选以18 mg·L~(-1)为宜;羧苄青霉素抑菌浓度早期以500 mg·L~(-1)为宜,后期以250~300 mg·L~(-1)为宜.Hyg抗性再生植株经PCR、RT-PCR检测初步证实外源基因已转入7个转化株系的植物基因组DNA中并发生转录.转基因植株幼苗人工接种蚜虫实验表明,不同转化株系的抗蚜性差异较大,蚜口密度抑制率为12.2%~76.8%不等,平均蚜口密度抑制率为41.8%. 相似文献
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- 1 There is growing appreciation of climatic effects on insect population dynamics at the margins of distribution limits. Climatic effects might be less important and/or involve different drivers and processes near the centre of distributions.
- 2 We evaluated the effects of interannual variation in temperatures, radiation and precipitation on populations of pine processionary moth Thaumetopoea pityocampa in Central–South Portugal, a low altitude area with a relatively mild Mediterranean climate near the centre of the north–south range of the species.
- 3 We tested for effects of climate on mortality of young larvae, growth rates, final larval mass and fecundity.
- 4 Results indicated high mortality of early instars associated with low minimum and maximum daily temperatures and low precipitation. Low minimum temperatures were further associated with high parasitism by the larval parasitoid Phryxe caudata (Rondani) (Diptera, Tachinidae). Furthermore, larval growth rates were higher with high solar radiation during December and January, which was itself negatively related to precipitation and air temperature. Slow larval growth rates led to lower final mass at pupation in the spring, and smaller egg masses and smaller initial colony sizes during the next autumn.
- 5 Thus climatic factors, and temperature in particular, apparently contributed to population dynamics of T. pityocampa in the core of its distribution, as well as at its northern limits. The most specific climatic parameters of importance, however, and the connections between climate, physiology and insect demographics in the core area were clearly different from northern areas.