How our ancestors evolved and emigrated have long been heatedly disputed and pursued, and scientists from around the world have been working hard to reconstruct the emigration history of early humans by identifying and dating ancient sites of human habitation.
Approximately dated to about 1.77-1.85 million years ago (Ma), a site in Dmanisi, Georgia, was widely agreed to be the earliest skeletal and artefactual evidence for human occupation outside Africa. It is closely followed by several sites in Asia, including a site in Yuanmou, Yunnan, China. Two incisors from this site, believed to be from Homo erectus, are dated to about 1.7 Ma. In the summer of 2018, Dmanisi lost its title to a site on the Loess Plateau in China, however, as the result of a new dating jointly made by scientists from CAS and the University of Exeter, UK.
The landscape and loess-paleosol section of the Shangchen Paleolithic locality recently found by the joint team. The discovery here indicates that human beings might have emigrated out of Africa earlier than formerly believed. (Credit: GIG & IVPP)
Led by Prof. ZHU Zhaoyu from the CAS Guangzhou Institute of Geochemistry (GIG), Prof. HUANG Weiwen from the CAS Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, and Prof. Robin Dennell from the University of Exeter, UK, the joint team discovered a new human habitation site in the Paleolithic strata of the Shangchen locality in Lantian County on the southern Loess Plateau, China. They examined samples and artefacts from a largely continuous paleosol/loess sequence containing 17 artefact layers, and dated the lowest artefactyielding layer to about 2.12 Ma. They analyzed 96 artefacts unearthed from the strata, and determined that their ages ranged from about 1.26 Ma to about 2.12 Ma.
This new age makes Lantian overrun all other human habitation sites to become the oldest outside Africa.
Lantian caught the eye of paleoanthropologists quite early. It came to light in the 1960s, when a Homo erectus cranium was unearthed from the Gongwangling locality in Lantian County by IVPP scientists. The discovery excited the whole paleoanthropological world. The cranium was later named “Lantian man.” Its age has been kept in clouds, because the complicated geological environment there makes it very hard to accurately decide the age of the strata. It was once dated to about 1.15 Ma, and this remained unchanged until 2015, when Profs. ZHU and HUANG’s team updated the age to about 1.63 Ma.
Highlighted in this research is its interdisciplinary background, particularly the integration of stratigraphic, paleoanthropological, paleo-geomagnetic and paleo-climatic methods, and the key role played by the loess sequence previously established by outstanding geologists represented by the late Prof. LIU Dongsheng (LIU Tungsheng), a CAS Member.
而且，她还选择医院医务部副部长励丽出任基层服务指导科、慢病管理中心主任，实现两项工作的整合。而且，励丽主任本来就是内分泌科医生，一直都特别关注慢病管理模式探索。
Selected artefacts found in situ in layers S27-L28 (2.09-2.12 Ma), L27 (1.95-2.09 Ma), L25 (1.73-1.80 Ma) and S23 (1.59-1.65 Ma) from the Shangchen Paleolithic locality. (Credit: GIG & IVPP)
This age has now been further updated by the new results from the Shangchen locality, which is near to Gongwangling. This surprisingly old age suggests that we might need to re-examine the origin and emigration of early humans.
As commented by Prof. Andrew P. Roberts from Australian National University, this impressive work established the age as well as the paleo-climate and environment background of the earliest human habitation site outside Africa, and it has important implications for the understanding of human evolution.
针对应试教育所产生的弊端，首先教师应该抛开以学生成绩为全部侧重点的观念，在关注学生成绩的同时也应该注重学生在各个方面所取得的进步与提高。尤其是对于大学生，教师应该更注重他们的自主学习能力以及综合应用能力。每一个学生都是不同的，都有其自己的优势，教师应该善于去发现学生的每一个长处，比如说有的学生词汇量比较大，有的学生语法点掌握的特别牢固，有的学生的口语特别流利等等，教师应该关注这些细节，以此来给予每个学生鼓励。所以教师不应该只有一个评价标准，而是采取多元化的评价标准，在关注学生整体发展的同时更应该侧重他们每个个体的进步。
在判别网络D中，首先对输入做几个stride=2的卷积，当特征映射的大小变为4×4时，则又一次对文本编码结果执行一个全连接层，降低其维度，将降维后的结果拼接到这个大小为4×4的特征映射上。然后做一个1×1卷积，1×1卷积基本上是在相同维度空间上的线性投影（输入和输出通道的数量相同）[15]，并通过一个4×4卷积以计算来自的最终分数。在判别网络中，每层都使用批量规范化（Batch Normalization）和Leaky-Relu激活函数。
References
1. Zhaoyu Zhu＊, Robin Dennell＊, Weiwen Huang, Yi Wu, Shifan Qiu, Shixia Yang, Zhiguo Rao, Yamei Hou, Jiubing Xie, Jiangwei Han, Tingping Ouyang, Hominin Occupation of the Chinese Loess Plateau since About 2.1 Million Years Ago. Nature 559, 608-612 (Published: July 11, 2018). doi: 10.1038/s41586-018-0299-4
2. Zhaoyu Zhu＊, Robin Dennell＊, Weiwen Huang＊, Yi Wu, Zhiguo Rao, Shifan Qiu, Jiubing Xie, Wu Liu, Shuqing Fu, Jiangwei Han, Houyun Zhou, Tingping Ou Yang, Huamei Li, New Dating of the Homo Erectus Cranium from Lantian (Gongwangling), China. Journal of Human Evolution 78, 144-157 (Published: January 01, 2015). doi: 10.1016/j.jhevol.2014.10.001.
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