• Korean Journal of Social Welfare Studies
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• v.44 no.2
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• pp.437-463
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• 2013

As polarization and class reproduction between generations are considered to be serious problems in Korean society, increasing number of assortative mating, which means marrying between homogeneous family background, income class, and educational background, is on the spotlight socially. Some worry that the increase of assortative mating can reinforce closure of social mobility so it deepens inequality and limits class mobility between generations. This research analyzes the effects of accomplishment characteristics of husbands and wives and ascriptive characteristics of parents which consist the concept of assortative mating, on income, consumption, and assets those represent economic status of a family. The purpose of this research is to suggest empirical understanding on the role of assortative mating that affect on inequality within generations and income mobility between generations in Korean society. In the result of multiple regression analysis on the effect of assortative mating on income, consumption, and assets, high educational background was the factor that increase income and consumption level as accomplishment characteristics of assortative mating. As ascriptive characteristics of assortative mating, educational homogeneous of fathers was the factor that increased asset level. While accomplishment characteristics affect income and consumption, ascriptive characteristics of homogeneous had significant effect on assets. Thus, it was found that transfer between generations had effects around asset rather than income. In particular, ascriptive characteristics in young husbands and wives aged 20s or 30s had significant effect only on the assets.

• Animal cells and systems
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• v.1 no.4
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• pp.535-538
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• 1997

Allozyme variation of seven enzyme systems was analyzed from 202 individuals from four Korean populations of Atractomorpha lata. These populations exhibit higher levels of values of in most other insects with a mean 64% of polymorphic loci and a mean 0.384 of expected heterozygosity within populations. Fixation indices indicated considerable substructuring within populations sampled (mean $F_{is}=0.403)$, indicating probable inbreeding or assortative mating coupled with restricted migration between subpopulations. This was supported by the field observation that the species exists as small, discrete colonies in meadow habitats and females carry males. In addition, significant differences in allere frequencies between males and females at polymorphic loci examined (70%, 16 of 23 cases) could account for the observed heterozygote deficiencies.

• Animal Systematics, Evolution and Diversity
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• v.11 no.3
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• pp.359-377
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• 1995

Morphological and isozyme analyses were used to examine closely related species of Tridentiger obscurus and \ulcorner: brevispinis, a pair of cryptic species which has intricate problem with regard to species boundary, and to clarify the taxonomic position. In this study, it was revealed from their 17 allopatric streams that there are differences of band ornamentation on the lateral side and three genetic markers between two species. However, genetic relationship between them (S = 0.813, D = 0.192) was within the intraspecific level of similarity. However, at the sympatry of two species no hybrid was found except at Bangjuk stream where the electrophoretic hybrids with slight deficiency of heterozygosity were observed. It is shown that at sympatry there is a finer microenvironmental subdivision between two species at all populations including Bangjuk stream. To manifest the extent of assortative mating, four syrnpatric subpopulations at Bangjuk stream were analyzed for departure from Hardy-Weinberg equillibrium by F-statistics. All subpopulations were deviated significantly from the expectation under random mating. The evidences presented here supports the recognition of Tridentiger obscurus and T. brevispinis as semispecies in the late stage of reproductive isolation

• The Korean Journal of Zoology
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• v.18 no.3
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• pp.141-146
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• 1975

The purposes of this study were to investigate the frequencies of acatalasemia and hypocatalasemia in Korean population to compare with those of Japanese, Chinese and chiefly Taiwan population. The results obtained were as followings; 1. In south area of Korea, Jeonju, Gwangju, Busan and Daegu, a total of 3,629 individuals were tested. No acatalasemia was found but 0.26% of hypocatalasemia in Jeonju, 0% in Gwangju, 0.21% in Busan and 0.06% in Daegu were found. 2. The frequency of hypocatalasemia in south area of Korea was found to be lower than in middle area. 3. The frequency of hypocatalasemia in this study was similar to that of Chinese(in Taiwan) and higher than that of Japanese. 4. The reason of the geographical differences in the freqency of the hypocatalasemia was considered to be due to the natural selection. And the reason of the higher frequency of Korean population living in Japan was considered that originally the frequency of Korean population is higher, and the maintenace of this higher degree is obliged to the assortative mating beteen them.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.69-76
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• 2018

Sexual dimorphism in birds refers to male-female differences in body size, plumage, color and/or behavior. In general, many seabirds, including the family of Laridae, are monomorphic in plumage-color, which makes the determination of sex difficult in the field because both parents also tend to share a great portion of parental care. The development of an inexpensive sexing tool facilitates understanding the degree of sex-specific parental care in the evolution of the life history. Here, we developed a non-invasive method for the determination of sex using the bill-head morphometric of known captive pairs and applied this tool to wild pairs to document factors underlying male-female parental care during the incubation period of Saunders's gulls (Saundersilarus saundersi). Males exhibited relatively larger bill-head ratios than their mates within naturally formed pairs in captivity, resulting in the determination of sex in12 wild pairs at the nest during the incubation period. Males and females equally shared the incubation role during the daytime, attending the nest at a high rate of 95%. However, the male's proportion of nest attentiveness greatly increased with time towards sunset, presumably reflecting the male duty for nighttime incubation. The present study provides a non-invasive method for the determination of sex in a monomorphic seagull species and highlights how male-female incubation behavior is associated with time of the day, rather than other ecological conditions.