• Title/Summary/Keyword: Glacier

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Genetic Variation of nSSR Markers in Natural Populations of Abies koreana and Abies nephrolepis in South Korea (남한지역 구상나무와 분비나무 집단에서의 nSSR 표지 유전 변이)

  • Hong, Yong-Pyo;Ahn, Ji-Young;Kim, Young-Mi;Yang, Byeong-Hoon;Song, Jeong-Ho
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.577-584
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    • 2011
  • To estimate level of genetic variation and genetic differentiation among populations of 3 populations in Abies koreana and 5 populations in Abies nephrolepis, 5 nSSR markers were analyzed. Except 1 locus where too many alleles were observed excessively, population genetic parameters were recalculated with 4 loci. Mean expected heterozygosities ($H_e$) were 0.292 in A. koreana and 0.220 in A. nephrolepis, respectively. In both species, positive fixation coefficient was estimated (F=0.065 for A. koreana and F=0.095 for A. nephrolepis), which suggests that there is an excess of homozygotes relative to Hardy-Weinberg expectations within populations. Relatively high degree of population differentiation was observed in A. koreana ($F_{ST}=0.063$). compared to that of A. nephrolepis ($F_{ST}=0.039$). From 3-level Hierarchical estimation of F-staticstics, only 4.9% of the genetic variation was allocated between species ($F_{PT}$), which suggested that most of genetic variation was shared between two species. On the basis of results from analysis of genetic relationships among populations, 2 populations of A. koreana (Mt. Halla and Mt. Deogyu) were genetically distinct from the populations of A. nephrolepis but a population of Mt. Jiri was allocated within a group of populations of A. nephrolepis. Populations of both species seemed to have undergone genetic drift due to gradual decrease in population size induced by global warming after the last glacier, which resulted in increase of homozygotes by inbreeding. It could be also postulated that these species might be diverged recently and It is likely that the two species have not fully speciated yet.

Qualitative Meta-analysis on Students' Understanding of Earth Science Concepts from the Perspective of Collective PCK: Focusing on the Concepts of Greenhouse Effect, Global Warming, and Climate Change (집단적 PCK 관점에서 학생들의 지구과학 개념 이해에 대한 질적 메타 분석: 온실 효과, 지구 온난화, 기후변화 개념을 중심으로)

  • Kwon Jung Kim;Eui Seon Choi;Ho Jun Kim;Jae Yong Park;Ki Young Lee
    • Journal of the Korean earth science society
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    • v.45 no.3
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    • pp.239-259
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    • 2024
  • In this study, a qualitative meta-analysis was conducted on research papers on earth science education to derive knowledge of students' understanding of specific science topics-greenhouse effect, global warming, and climate change-within the context of collective Pedagogical Content Knowledge (PCK). Twenty-two research papers addressing students' alternative conceptions (misconceptions) about these topics were selected and analyzed for their respective definitions, causes (mechanisms), and impacts. Semantic network analysis and a mental model framework were applied to synthesize the findings. The meta-analysis revealed several key insights: (1) Regarding the greenhouse effect, students often used the terms "greenhouse effect" and "global warming" interchangeably, lacked knowledge about the types of greenhouse gases, and misunderstood their roles. They commonly associated the greenhouse effect with environmental pollution or changes in the ozone layer, failing to recognize its relation to the heat balance between the surface and atmosphere. (2) Concerning global warming, students confused it with sea level rise and linked it to pollution, ozone layer changes, and glacier melting. They understood global warming as a disruption of the heat balance between the surface and atmosphere but had misconceptions about its environmental impacts. (3) In terms of climate change, students used the term interchangeably with global warming, weather change, and climate anomalies. They associated climate change with atmospheric pollution and ozone layer depletion but misunderstood its environmental impacts. As result, three mental models-categorical, mechanistic, and hierarchical misconceptions-were identified as collective PCK. The implications for enhancing earth science teachers' PCK were discussed based on these findings.