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蓝海人类学在线 Ryan WEI's Forum of Anthropology

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楼主: cpan0256

现代人经历过两次与丹尼索瓦人的混合

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发表于 2018-3-17 15:16 | 显示全部楼层
两种丹人很有意思,他们是怎么分离的呢?

是一支走南线,一支走北线?还是南从北分离?还是北从南分离?

丹人的遗骸除了阿尔泰,还没有在南方发现过,而尼人的遗骸也只在欧亚北部发现。
lindberg 发表于 2018-3-17 12:00
没在南方发现过?丹人是不断向北退却,最晚的遗址在北方被发现,现在丹人成分最好的就是巴布亚人
发表于 2018-3-17 15:21 | 显示全部楼层
文章似乎没有给出两次与丹人混合的年代,有无这种可能:智人先与丹人在北方混合,然后一部分混合智人南下独立发展,过了N多年,另一波混合智人又南下,与第一波混合,于是就出现了两种成分。
lindberg 发表于 2018-3-17 13:11
你要这么理解的话,反过来讲今天丹尼索瓦成分最高的巴布亚人是不是早期分布在西伯利亚地区?巴布亚人鼻子倒是挺高的。
发表于 2018-3-17 16:35 | 显示全部楼层
本帖最后由 lindberg 于 2018-3-17 16:43 编辑
没在南方发现过?丹人是不断向北退却,最晚的遗址在北方被发现,现在丹人成分最好的就是巴布亚人
wanhuatong 发表于 2018-3-17 15:16

目前为止,不是只在阿尔泰发现过丹人遗骨吗?别的地方还真没听说过。
发表于 2018-3-17 16:40 | 显示全部楼层
本帖最后由 lindberg 于 2018-3-17 16:41 编辑

22# wanhuatong
The component closely related to the Altai Denisovan is primarily present in East Asians, whereas the component more distantly related to the Altai Denisovan forms the major part of the Denisovan ancestry in Papuans and South Asians. The East Asian populations are the only populations with relatively equal and non-negligible contributions from both components, and it is in these populations that the two waves of Denisovan admixture are most evident.

文章不是说,阿尔泰的丹人成分主要在现代东亚人身上;

南亚人和巴布亚人主要是另一种丹人成分;

东亚人是两种都有,比重还比较均衡。
发表于 2018-3-17 16:48 | 显示全部楼层
巴布亚人的丹人成分的确是与众不同,不过他们的丹人成分按照马普所的分析主要属于南方型丹人成分,兼有与东亚人群共享的北方型丹人成分,而这种北方型丹人成分也影响到了更加北方的阿尔泰尼人,不过极少(略大于千分之五)。     不过关于丹人,我们现在知道的太远远不够……



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发表于 2018-3-17 17:20 | 显示全部楼层
22# wanhuatong

文章不是说,阿尔泰的丹人成分主要在现代东亚人身上;

南亚人和巴布亚人主要是另一种丹人成分;

东亚人是两种都有,比重还比较均衡。
lindberg 发表于 2018-3-17 16:40
哦哦,东亚人群与这个阿尔泰丹人混合过。
发表于 2018-3-17 17:22 | 显示全部楼层
那这两种丹人之间的遗传距离如何呢?
发表于 2018-3-17 23:33 | 显示全部楼层
看来亚欧智人的丹人成分也是很不均匀的

In the 1000 Genomes Eurasian populations, the detected putative introgressed haplotypes have median lengths ranging from 59 kb in Bengalis (BEB) to 71 kb in Finns (FIN). Due to tiling across individuals, the full segments that our method reports can be much longer (Figure 2). In the Eurasian 1000 Genomes populations, the median segment length varies from 205 kb in Iberians (IBS) to 239 kb in Telugus (ITU). The longest detected segment is 7.9 Mb.

发表于 2018-3-18 00:52 | 显示全部楼层
从这个表看,东亚人种起源于我之前认为的华中地区是极有可能的
Two-Component Mixtures for Denisovan-Related Introgression

Population[td=1,1,72]μ1[/td]μ2σ1σ2比例Pp value
Southern Han Chinese0.820.460.080.120.420.00002
Han Chinese (Beijing)0.840.50.080.140.360.00021
Chinese Dai0.860.520.040.180.20.00069
Japanese (Tokyo)0.860.520.060.180.260.00143
Finnish0.840.50.040.140.220.00348
Punjabi (Pakistan)0.820.480.10.120.10.04589

.
Populations with a p value < 0.05 for a two-component mixture are shown, ordered by p value. p values should be compared to a Bonferroni-corrected threshold of Math Eq since 19 non-African populations from the 1000 Genomes Project were tested. μ1 and μ2 are the estimated mean per-segment matching of putative archaic-specific variants to the Altai Denisovan genome for the two components; σ1 and σ2 are the estimated standard deviations of per-segment matching for the two components; P is the proportion of segments attributed to the first (high-affinity) component; and the p value is for a likelihood ratio test for the two-component Gaussian mixture versus a single Gaussian distribution.
发表于 2018-3-18 10:53 | 显示全部楼层
本次作者团队采用的分析方法非常多,昨晚看得有一点目不暇接,估计视力减退了至少0.25
发表于 2018-3-18 11:19 | 显示全部楼层
作者团队的结案陈词是这样的:
Overall, East Asians and South Asians carry similar amounts of detected Denisovan ancestry, while Papuans carry much more detected Denisovan ancestry (Figure 5). Approximately one-third of the Denisovan ancestry segments in the East Asians are from the high-affinity component (Table 2), whereas very little of the Denisovan ancestry in the South Asians and Papuans is from the high-affinity component (Figure 4). A possible scenario consistent with this pattern would have the high-affinity component introgressing into East Asia after the split between East and South Asia. Because the Papuans have a much higher frequency of the moderate-affinity Denisovan component than other populations, it may be that this component was primarily introgressed into the ancestors of Papuans after they split from Asia, and arrived in Asia via migration from the ancestors of Papuans; however, other scenarios are also possible (Prüfer et al., 2014, Sankararaman et al., 2016).

我的推测是这样的:

CF人群在南亚或南亚附近某地开始东西大分离之后,东进的CF人群在南亚或中南半岛北部某地发生第一次与亚洲土著丹人的混合(我定义为北方型丹人,即文中的“archaic people with the high-affinity component),不过这次混合的规模不大。
之后东亚欧古人发生分离,北上的是我们的NO先祖以及C2人群(可能走东线),他们在华中某地遭遇到北方丹人的主力(十堰古人或许昌古人的后代? 更有可能是中国丹人与早期智人的混血种),双方开始长期的大规模混合,形成最早的‘东亚人种’,或是未来‘东亚人种’的主力;
而另一支继续东进的EE人群应该在中南半岛南部与南方型丹人遭遇,几场大战之后,双方开始融合,继之在印尼或华莱士分界线附近,他们的融合达到高潮,形成一个新人种---‘巴布亚人种’。

特别值得指出的是,现在南亚存在的两种成分,更多的是后期‘东亚人种’与‘巴布亚人种’回流的结果,尽管ASE 人群同时也为前二者不断地输送血液...

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发表于 2018-3-18 12:31 | 显示全部楼层
现在这些对于现代人常染中早期智人的成分研究来看,那些分布在欧亚大陆和太平洋地区的4万年前的早期智人,的确是被出非洲体质上的现代人迅速排挤消灭殆尽了。而且从人种间混血的广泛程度看,双方不是以前某些人假想的“你进我退”的温和方式,而是很可能带有一定暴力成分。
发表于 2018-3-18 19:50 | 显示全部楼层
现在这些对于现代人常染中早期智人的成分研究来看,那些分布在欧亚大陆和太平洋地区的4万年前的早期智人,的确是被出非洲体质上的现代人迅速排挤消灭殆尽了。而且从人种间混血的广泛程度看,双方不是以前某些人假想的 ...
baiyueren 发表于 2018-3-18 12:31


如果真是这样,其实有一个间接证据。旧大陆只有澳大利亚土著没有弓箭,可能这些早期智人缺乏这种武器。
发表于 2018-3-18 20:02 | 显示全部楼层
从这个表看,东亚人种起源于我之前认为的华中地区是极有可能的
Two-Component Mixtures for Denisovan-Related Introgression

Populationμ1μ2σ1σ2比例Pp valueSouthern Han Chinese0.820.460.080.120.420.00 ...
imvivi001 发表于 2018-3-18 00:52

怎么讲呢?
发表于 2018-3-18 21:00 | 显示全部楼层
如果真是这样,其实有一个间接证据。旧大陆只有澳大利亚土著没有弓箭,可能这些早期智人缺乏这种武器。
skyyrie 发表于 2018-3-18 19:50

弓箭在远古也算是高科技了~
发表于 2018-3-18 21:04 | 显示全部楼层
35# lindberg
请看表格数字认真领悟一下~
发表于 2018-3-18 22:24 | 显示全部楼层
看来咱们东亚人的强大还要感谢尼人先祖呢,呵呵

The second of these immunity-related regions is on chromosome 14q32.33. The introgressed alleles in this region are at very high frequency throughout Eurasia. This region is located in the immunoglobulin heavy locus, which contains multiple genes that code for antibodies (Schroeder and Cavacini, 2010). Immunoglobulin heavy genes contained within the high-frequency region are IGHA1, IGHG1, and IGHG3. The most highly conserved introgressed position is rs10144746 (PhyloP score 4.1) and is an expression quantitative trait locus (eQTL) for IGHG4 and several other immunoglobulin heavy genes in various tissues including esophagus and liver. The high-frequency introgression is in a region with significant masking of the Altai Neanderthal and Altai Denisovan genomes due to poor quality sequence. For example, for the segment found in the Southern Han Chinese (CHS) population, 119 of the 145 putatively introgressed alleles are filtered in the Altai Neanderthal genome (see the STAR Methods). Of the 26 unfiltered alleles, 22 match the Altai Neanderthal genome. Thus this region appears to be derived from Neanderthal admixture, but would be difficult to find using a reference-based approach
发表于 2018-3-18 22:30 | 显示全部楼层
数据里没有藏族的数据,也许和傣族差不多
发表于 2018-3-18 22:38 | 显示全部楼层
35# lindberg
请看表格数字认真领悟一下~
imvivi001 发表于 2018-3-18 21:04

哪儿能看出来啊,从古至今人群又不是固定不动的。
发表于 2018-3-18 23:15 | 显示全部楼层
40# lindberg
这个可能需要你了解更多相关的数据,也需要一些领悟力~
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