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81.
Michael Gudo 《Theorie in den Biowissenschaften》2002,121(1):101-137
Summary The critical theory of evolution was developed by a group of scientists working together with Wolfgang F. Gutmann at the Senckenberg-Research-Institute
in Frankfurt am Main. Gutmann worked at Senckenberg for 37 years. In this time he presented 247 contributions which are distributed
over 47 periodicals and books. The ideas that were developed by Gutmann and his colleagues were innovative and pathbreaking
for morphology and evolutionary biology. The large number of his morphological publications is indicative of the wide field
that was opened up by the concepts of constructional morphology. As some of his colleagues have suggested, constructional
morphology as an engineering approach to the study of organisms (i. e., engineering morphology) may replace the traditional
concepts of morphology and anatomy and provides the observational base for the historical reconstruction of evolutionary pathways.
Constructional morphology as a quasi-engineering approach can be the morphological pendant to the contemporary molecular approaches
to biology, as it can provide the necessary morphological basis for the interpretation of the results of molecular studies
in the light of evolution. 相似文献
82.
83.
Anton Weber 《Plant Systematics and Evolution》1987,157(3-4):187-199
Phyllagathis tuberculata
King and two closely allied new species,P. magnifica
A. Weber andP. stonei
A. Weber, are described and illustrated. Within the genus, these species form a distinct and isolated group which is restricted to Peninsular Malaysia.P. tuberculata occurs in Perak (probably confined to G. Bujang Melaka),P. magnifica andP. stonei are found in the mountains on the Pahang/Selangor border (Genting Highlands, Gombak valley). The distinctive characters of the three species are listed and some general information relating to inflorescence morphology, tubercle anatomy, fruit structure and seed dispersal is provided. 相似文献
84.
85.
Intraspecific Variation in Cryptocaryon irritans 总被引:10,自引:0,他引:10
ABSTRACT. Intraspecific variation in the ciliate Cryptocaryon irritans was examined using sequences of the first internal transcribed spacer region (ITS-1) of ribosomal DNA (rDNA) combined with developmental and morphological characters. Amplified rDNA sequences consisting of 151 bases of the flanking 18 S and 5.8 S regions, and the entire ITS-1 region (169 or 170 bases), were determined and compared for 16 isolates of C. irritans from Australia, Israela and the USA. There was one variable base between isolates in the 18 S region nd 11 variables indicate that Australian C. irritans isolates from estuarine (Moreton Bay) and coral reef (Heron Island) environments are distinct. The Heron Island isolate was genetically closer to morphologically dissimilar isolates from Israel (1.8% divergence) and USA (2.3 % divergence) than it was to the Moreton Bay isolates. Three isolates maintained in our laboratory since February 1994 originated from the same source. During this time the sequence of the isolates from wild fish in Moreton Bay remained unchanged. These genetic differences indicate the existence of a founder effects in laboratorty populations of C. irritans . The genetic variation found here, combined with known morphological and developmental differences, is used to characterise four strains of C. irritans . 相似文献
86.
PASCAL NEIGE DIDIER MARCHAND BERNARD LAURIN 《Lethaia: An International Journal of Palaeontology and Stratigraphy》1997,30(2):145-155
Ontogenetic and then heterochronic approaches are used here to analyze sexual differentiation within two well-known Jurassic dimorphic species. This analysis compares two ways of determining the relative biological age of ammonites, one using size (diameter) and the other the number of septa as a proxy of age. The shape standard is established from factor analysis of morphological and growth parameters. Size-age-shape relationships are analyzed on the basis of a new heterochronic representation. When diameter is used as a proxy of age, microconch morphs are globally considered to be progenetic compared with macroconch morphs. When size and age are determined separately and shape is included, (1) Ebrayiceras jactatum (microconch morph) has a shorter period of growth (progenesis) with acceleration of shape compared with its macroconch morph ( Morphoceras macrescens ), (2)( Cardioceras cordatum (microconch morph) has a shorter period of growth (progenesis) coupled with a slower rhythm of growth (dwarfism) compared with its macroconch morph. These findings emphasize the complex relationship between supposed sexual dimorphs in ammonites when size and age standards can be separated, as well as the need for an ontogenetic approach. 相似文献
87.
AL A. DÖNMEZ 《Botanical journal of the Linnean Society. Linnean Society of London》2007,155(2):231-240
The Turkish Crataegus taxa were investigated using morphological, palynological, and anatomical characters. A new series ( Crataegus Section Crataegus Series Peshmenia ), two new species ( Crataegus peshmenii and Crataegus christensenii ), and one variety ( Crataegus rhipidophylla var. kutahyaensis ) are described. Furthermore, Crataegus × browicziana has been assigned to Crataegus rhipidophylla with a new status. Illustrations of the described taxa and their distribution map are also given. The lectotype for Crataegus yaltirikii is designated here. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 231–240. 相似文献
88.
Sk Moquammel Haque 《Grana》2017,56(2):124-136
The various normal and abnormal stages of meiosis and pollen mitosis of Drimiopsis botryoides are described, and a comparison between naturally propagated in vivo and tissue culture derived ex vitro plants in respect to their cytological behaviour presented. We also describe the floral morphology and investigate the relationship between the floral developmental stages and the progression of microgametogenesis. In total, 33 bivalents are observed in diakinesis, which indicate the diploid number 2n = 66 and this number is cross-checked by a haploid set of n = 33 chromosomes in pollen mitosis. Only 6.8% and 4.9% meiotic abnormalities were recorded on in vivo and ex vitro plants, respectively, which led to the formation of non-viable pollen. Finally, the microspores have to develop into tri-cellular male gametophyte. Only 0.2% pollen grains are found with a micro-nucleus. Though the higher pollen viability was recorded on both in vivo (89.3 ± 4.1%) and ex vitro (92.1 ± 4.6%) plants, but surprisingly the pollen germination rate is extremely low with 13.6 ± 1.74% and 21.3 ± 1.55%, respectively. The present study obviously enriches the cytological database of D. botryoides and may help future research on androgenesis and genetic improvement. 相似文献
89.
Population differentiation in Crepis tectorum (Asteraceae): patterns of correlation among characters
STEFAN ANDERSSON 《Biological journal of the Linnean Society. Linnean Society of London》1993,49(2):185-194
This study examines the relationship among traits distinguishing populations of C. tectorum and the extent to which existing trait associations reflect underlying (genetic) tradeoffs. Highly consistent trait associations were found in a comparison of 52 populations representing the western part of the geographical range of the species. In addition to a tight integration of traits reflecting plant stature and inflorescence development, there were consistent links between vegetative and reproductive traits; populations characterized by individuals with large leaves and tall stems with terminal branches usually had larger heads, flowers and fruits (achenes) than those whose individuals had small leaves and a short stem branched from the base. There was a weak negative relationship between the extent of leaf dissection and plant stature; short and compact plants had more deeply lobed leaves than tall plants with terminal branches. Few of these associations were present among families representing a single population of C. tectorum , but there was remarkable similarity between the correlations at the between-population level and those obtained in two segregating F2 progenies of crosses between contrasting populations. Hence, provided that the F2 correlations have a strong genetic basis, it appears that the course of population divergence has been constrained by the underlying correlation structure, although some trait associations may also be a result of selection operating in a correlated fashion on functionally related traits, perhaps leading to linkage disequilibrium of parental traits in the first segregating generation of a cross between ecologically differentiated populations. 相似文献
90.
Harihara M. Mehendale 《Phytochemistry》1973,12(7):1591-1594
Aldrin epoxidase activity of the cell-free pea and bean root preparations was located in the particulate fraction. High speed centrifugation at 250 000 g for 2 hr resulted in a pellet with almost all the activity of the crude cell-free preparations. While the epoxidase was stimulated by NADPH generating system in these cell-free root preparations, that in high speed centrifugation pellets was not. Aldrin epoxidase activity of the dwarf bean root homogenates was increased by addition of p-aminobenzoic acid (10?4 M). This increase in activity is above that already manifested by Polyclar AT. No activity was detected in the dormant or germinating Alaska peas or dwarf beans until the 5th and 6th day, respectively. 相似文献