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Pairwise Shared Genealogical Ancestry in Structured Populations 被引量:1
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作者 Philip M. Service 《Natural Science》 CAS 2022年第8期305-321,共17页
Simulation was used to investigate the effects of population structure and migration on metrics of pairwise shared ancestry. Random and hierarchical structures, or migration geometries, were examined. Compared to panm... Simulation was used to investigate the effects of population structure and migration on metrics of pairwise shared ancestry. Random and hierarchical structures, or migration geometries, were examined. Compared to panmictic populations, progress to all qualitative metrics of pairwise ancestry is delayed in structured populations. However, unless migration is very low, the time required is generally less than triple and often less than twice that required in a panmictic population of the same total size. Population structure also increases, to a similar degree, the time required for a population-wide most recent common ancestor (MRCA). As a result, the relationships between various qualitative metrics of pairwise shared ancestry and MRCA time are relatively unaffected by population structure. For example, the mean time to most recent shared ancestor (MRSA) with global sampling of pairs is 40% - 50% of the MRCA time for almost all simulated structures and migration levels. Quantitative pairwise genealogical overlap is strongly affected by population structure. With global sampling, pairwise quantitative overlap never approaches 1.0, as it does in panmictic populations;and instead eventually becomes stationary at much lower values. Possible implications of the present results for human pairwise shared ancestry are discussed. For globally sampled pairs, the longest time to most recent shared ancestor (MRSA) for humans is suggested to be approximately 2100 years before the present. If generation time is 30 years, then all humans are 69th, or closer, cousins. For people with recent European ancestry, the MRSA time may be only half as long, about 1000 years. 展开更多
关键词 Population Structure Pairwise Shared Ancestry GENEALOGY MIGRATION Most Recent common ancestor Humans
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Pairwise Shared Ancestry in Random-Mating Constant-Size Populations 被引量:2
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作者 Philip M. Service 《Natural Science》 2022年第5期193-202,共10页
In a panmictic population of constant size N, random pairs of individuals will have a most recent shared ancestor who lived slightly more than 0.5 log<sub>2</sub>N generations previously, on average. The p... In a panmictic population of constant size N, random pairs of individuals will have a most recent shared ancestor who lived slightly more than 0.5 log<sub>2</sub>N generations previously, on average. The probability that a random pair of individuals will share at least one ancestor who lived 0.5 log<sub>2</sub>N generations ago, or more recently, is about 50%. Those individuals, if they do share an ancestor from that generation, would be cousins of degree (0.5 log<sub>2</sub>N) - 1. Shared ancestry from progressively earlier generations increases rapidly until there is universal pairwise shared ancestry. At that point, every individual has one or more ancestors in common with every other individual in the population, although different pairs may share different ancestors. Those ancestors lived approximately 0.7 log<sub>2</sub>N generations in the past, or more recently. Qualitatively, the ancestries of random pairs have about 50% similarity for ancestors who lived about 0.9 log<sub>2</sub>N generations before the present. That is, about half of the ancestors from that generation belonging to one member of the pair are present also in the genealogy of the other member. Qualitative pairwise similarity increases to more than 99% for ancestors who lived about 1.4 log<sub>2</sub>N generations in the past. Similar results apply to a metric of quantitative pairwise genealogical overlap. 展开更多
关键词 Pairwise Shared Ancestry Genealogical Overlap Quantitative Ancestry Most Recent common ancestor Number of Cousins
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北朝炎黄祖先记忆与“中华”认同 被引量:4
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作者 陈鹏 蒋晓斐 《赤峰学院学报(哲学社会科学版)》 2022年第8期17-25,共9页
炎帝、黄帝作为中华民族“共祖”,是由中国历史上各民族共同确立的,而北朝是炎黄祖先“共祖”身份确立的关键时期。十六国至北魏,边疆民族进入中原建立政权后,往往祖述炎黄,以促使本族“华夏化”,确立民族政权的合法性。北魏孝文帝迁洛... 炎帝、黄帝作为中华民族“共祖”,是由中国历史上各民族共同确立的,而北朝是炎黄祖先“共祖”身份确立的关键时期。十六国至北魏,边疆民族进入中原建立政权后,往往祖述炎黄,以促使本族“华夏化”,确立民族政权的合法性。北魏孝文帝迁洛,施行“汉化”改革,推动了各虏姓家族接受“炎黄子孙”身份。至西魏北周,炎帝、黄帝成为关陇地区鲜卑、汉人、氐羌诸族共同尊奉的祖先。至此,炎黄祖先正式由“华夏先祖”发展为“华夷共祖”,并影响到后来突厥、契丹诸族。这推动了历史上中华民族共同体意识的自觉和发展。 展开更多
关键词 北朝 炎黄祖先 华夷共祖 中华认同
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论中国疆域最终形成的路径与模式 被引量:7
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作者 于逢春 《长春师范大学学报(人文社会科学版)》 2012年第11期1-13,共13页
迄今为止,世界级前近代帝国在大国游戏中被淘汰出局后,其嫡传文化继承者能够凤凰涅磐且成功地重返世界大国之列者,惟有中国。与世界其他几个从大河流域崛起的世界级帝国的核心力量都是在帝国中心地带兴起,一旦灭亡,支撑着帝国的核心力... 迄今为止,世界级前近代帝国在大国游戏中被淘汰出局后,其嫡传文化继承者能够凤凰涅磐且成功地重返世界大国之列者,惟有中国。与世界其他几个从大河流域崛起的世界级帝国的核心力量都是在帝国中心地带兴起,一旦灭亡,支撑着帝国的核心力量便随之冰消瓦解的情景不同,古代中国的世界级帝国均形成于中原地带的边缘,他们为中国链条式世界级帝国的形成提供了源源不断、前仆后继的能量。虽然这些帝国建立者出身的民族(族群)各不相同,但维系帝国链条运作的"大一统"思想、"天下观"理论、"华夷共祖"谱系等古代中国文化从来没有中断过,从而使得古代中国的各个世界级帝国之间具有内在的文化承继性与疆域连续性。 展开更多
关键词 帝国 五大文明板块 大一统 天下观 华夷共祖
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