• Journal of Ecology and Environment
• /
• v.31 no.1
• /
• pp.75-81
• /
• 2008

Rates of molecular evolution are known to vary widely among taxonomic groups. A number of studies, examining various taxonomic groups, have indicated that body size is negatively and clutch size is positively correlated with the rates of nucleotide substitutions among vertebrate species. Generally, either smaller body mass or larger clutch size is associated with shorter generation times and higher metabolic rates. However, this generality is subject to ongoing debate, and large-scale comparative studies of species below the Order level are lacking. In this study, phylogenetically independent methods were used to test for relationships between rates of the mitochondrial cytochrome b evolution and a range of life history traits, such as body mass and clutch size in the Order Galliformes. This analysis included data from 67 species of Galliformes birds and 2 outgroup species in Anseriformes. In contrast to previous studies, taxa were limited to within-Order level, not to Class or higher. I found no evidence to support an effect of life history traits on the rate of molecular evolution within the Galliformes. These results suggest that such relationship may be too weak to be observed in comparisons of closely related species or may not be a general pattern that is applicable to all nucleotide sequences or all taxonomic groups.

• Journal of the Korean Home Economics Association
• /
• v.37 no.2
• /
• pp.55-72
• /
• 1999

The purpose of this study was to investigate developmental trends in organization strategy for taxonomic and slot-fiber lists and category typicality, use of organization strategy in relation to developmental changes in category knowledge structure, emergent organization capacity and effects in category typicality on children's recall. Moreover, the influences of children's age, use of organization strategy, list types and category typicality on children's recap were figured out. The major results were as follows. 1. Children's recall use of organization strategy increased with age. That is, the older children performed better recap and used organization strategy on both list types than the younger children. 2. AU children performed recall and used organization strategy better for the slot-filler than taxonomic list. The 4-year-olds, however, demonstrated better recap and use of organization strategy for the slot-filler than taxonomic list. While the 6-year-olds and 8-year-olds showed no such differences. These findings were supported the view that script-based slot-filler categories have a strong influence on young children's memory performance. 3. At each age level, children showed higher level of recall and use of organization strategy for category typical than category atypical list. AU children received higher scores for the typical than atypical items on recap and use of organization strategy. 4. Children's age, use of organization strategy, list types, and category typicality of lists significantly predicted children's recap.58% of the variance of children's recap was explained by four variables.

• ALGAE
• /
• v.18 no.4
• /
• pp.239-253
• /
• 2003

The morphotaxonomic characters of the genus Spirogyra were investigated to clarify their taxonomic category and the variation range among species on the basis of comparative morphological and numerical analyses by unialgal cultures and field samples collected from various freshwater habitats in Korea. 25 characters selected on morphological feature of the species were examined on 568 individuals for morphological comparisons and numerical analyses. Width, length and their length/width ratio of vegetative cell, shape of septum, chloroplast number, maximum width, width, length and their length/width ratio of female gametangium, length of male gametangium, size and shape of zygospore, and cell wall ornamentation of the spore showed a comparatively high vector in principal component analysis. In cluster analysis, 15 taxa analysed were divided into 8 major groups by the average taxonomic distance 1.0 level. Considering the morphology and numerical analysis, Spirogyra crassoidea could not be recognized as an independent species, therefore it was treated as a variety of S. ellipsospora. S. koreana (nom. invalidum), recognized as a new taxon, is under the investigation for its clear taxonomic category.

• Journal of the Korean School Mathematics Society
• /
• v.14 no.2
• /
• pp.143-161
• /
• 2011

Mathematics PBL, which has recently attracted much attention, is a teaching and learning method to increase mathematical ability and help learning mathematical concepts and principles through problem solving using mathematical knowledge the students have. In spite of the attention, however, the implementations are yet significant. In this study, we worked to find the needs of mathematics teachers for mathematics PBL implementation. The methods of this study are taxonomic analysis and componential analysis by using cards depth interviewing. As a result, mathematics teachers' needs are to consider how to develop the mathematics PBL problems and how to make progress.

• The Korean Journal of Mycology
• /
• v.26 no.4 s.87
• /
• pp.437-449
• /
• 1998

This paper is a fourth contribution towards taxonomic studies on Cercospora and allied genera, and contains ten species of Korean cercosporoid fungi; viz. Cercospora capsici, C. cardaminae, C. nasturtii, Phacellium episphaerium, Pseudocercospora chengtuensis, P. diospyrimorrisianae, Pseudocercosporella capsellae, Ramularia armoraciae, R. lamii var. lamii, and R. pratensis var. pratensis. Morphological characteristics of taxonomic value are described and drawn for these species to contribute towards a mycological monograph of Korean cercosporoid fungi.

• Journal of Life Science
• /
• v.14 no.1
• /
• pp.57-60
• /
• 2004

To get basic information on the Korea local corn lines collected from Busan and Gyungnam Province, a total of 49 lines were classified by the principal component analysis method. The lines were classified into 4 lineal groups by the taxonomic distance. Croup I included 11 lines, and groupII, groupIII and groupIV included 20 lines, 14 lines and 4 lines, respectively. Four groups could be characterized as follows: Croup I : early maturity, short plant, small ears, small kernels, low tillering and medium yielding. Croup II : early maturity, tall plant, large ears, large kernels, multi-ears, low tillering and high yielding. GroupIII: late maturity, short plant, small ears, small kernels, high tillering and low yielding. Croup W medium maturity, tall plant, large ears, small kernels, prolific ears, high tillering and higher yielding.

• Fisheries and Aquatic Sciences
• /
• v.17 no.1
• /
• pp.137-143
• /
• 2014

The hairtail (currently recognized as Trichiurus lepturus in Korea) is one of the most important commercial fish species in Korea, Japan, China, and Taiwan. Because the amount of catches has been steadily declining, we must determine the early life stages of the hairtail from the viewpoint of resource management. Furthermore, the taxonomic status of the hairtail is unclear among ichthyologists, potentially creating management difficulties. Therefore, the purpose of this study was to compare morphological and molecular information on eggs, larvae, and adults of hairtail from Korea with that of T. lepturus from the Atlantic Ocean, and to review the taxonomic status of the hairtail. A total of 510 base pairs of the mitochondrial DNA cytochrome oxidase subunit I sequences of 12 eggs, 2 larvae, and 11 adults of the hairtail from the Korean waters clearly matched those of Trichiurus japonicus adults (d = 0.000-0.014) from the East China Sea rather than those of T. lepturus (d = 0.100-0.110) from the Atlantic Ocean. Our results also showed that larvae of the Korean hairtail are different than those in the Atlantic Ocean in having no melanophores along the ventral edge of the lower jaw. Therefore, our findings suggest that the hairtail in the Korean waters may not be T. lepturus, but T. japonicus.

• Korean Journal of Plant Taxonomy
• /
• v.47 no.1
• /
• pp.6-10
• /
• 2017

Microsatellite markers were isolated for Daphne kiusiana var. kiusiana (Thymelaeaceae), an evergreen broad-leaved shrub endemic to Korea and Japan. Because its populations in Jeju Island are morphologically controversial, and consistently threatened by anthropogenic pressures, taxonomic delimitation and conservation effort are required at the genetic level. We developed 21 polymorphic microsatellite loci from Next Generation Sequencing data. The primer set included di-, tri-, and tetra-nucleotide repeats. Variability in the markers was tested for 80 individuals of D. kiusiana from three natural populations in Jeju Island and Japan. Among the 21 loci, three were unavailable for population JKJU of Japan. The Neighbor-Joining tree based on microsatellite markers described here classified the three populations into two groups according to geographical or morphological traits. These will be a powerful genetics tool for determining the taxonomic boundary and establishing suitable conservation strategies for D. kiusiana in Jeju Island.

• Korean Journal of Plant Taxonomy
• /
• v.38 no.2
• /
• pp.111-120
• /
• 2008

Taxonomic identities of Utricularia japonica and U. tenuicaulis were examined. Utricularia japonica was differed from U. tenuicaulis by having a scape narrower than the stem, rather sparsely arranged leaves, and more or less oblong leaves. Utricularia japonica has been known to occur widely in Korea due to the misidentification of U. tenuicaulis, which is distributed widely in southern and middle Korea. However, only one population of U. japonica was found in Chunjin Lake, near Kosung-gun, Kwangwon-Do, in Korea.

• Korean Journal of Plant Taxonomy
• /
• v.38 no.3
• /
• pp.251-270
• /
• 2008

Members of the genus Asarum of Korea were reviewed taxonomically, and classified into seven species. Among them, four species - A. koreanum, A. maculatum, A. patens and A. versicolor - were recorded as Korean endemics. The most valuable taxonomic characters in identifying the Asarum taxa were shape, size and color of the calyx tube and lobe. In addition, the presence of white spots on the adaxial surface, size and color of leaf, presence of trichome, shape and size of the stylar protuberance and thickness of the calyx lobe were also important characters. Keys to the species including descriptions and figures of floral structures of each taxon were provided here for the accurate identification of each species.