5月6日,在南非约翰内斯堡,一名参观者注视着200多万年前的猿人完整头盖骨“普莱斯夫人”。自从1947年在南非斯泰克方丹出土以来,这枚轰动世界的头盖骨今年5月第一次公开展出。斯泰克方丹位于南非最大城市约翰内斯堡西北约50公里,其山谷洞穴内的化石记载着过去350万年里人类进化的信息。新华社发(南非新闻联合社)
美国等国一些科学家最新研究显示,非洲人基因最多元。这项研究结果还进一步佐证人类起源非洲说,将人类进化起源地范围缩小至今天南非和纳米比亚边境附近。
美国《科学》周刊电子版4月30日刊登这份研究报告。研究人员通过10多年非洲实地工作、比对分析不同族群基因信息后发现,非洲人基因变异最剧。
“基于现代人类起源非洲说,他们(非洲人)有时间展开强烈基因变异,”研究团队负责人、美国宾夕法尼亚大学女遗传学家莎拉·蒂什科夫说。
她进一步解释,这意味着非洲人在不断适应非洲大陆多变自然环境的过程中,基因同时发生变异。
研究人员说,科学家先前对非洲人的基因变异知之甚少。这项研究发现对于找到疾病对不同族群影响存在差异的原因、进而为对抗这些疾病“设计”不同治疗方案至关重要。(生物谷Bioon.com)
生物谷推荐原始出处:
Science DOI: 10.1126/science.1172257
The Genetic Structure and History of Africans and African Americans
Sarah A. Tishkoff 1*, Floyd A. Reed 2, Fran?oise R. Friedlaender 3, Christopher Ehret 4, Alessia Ranciaro 5, Alain Froment 6, Jibril B. Hirbo 1, Agnes A. Awomoyi 7, Jean-Marie Bodo 8, Ogobara Doumbo 9, Muntaser Ibrahim 10, Abdalla T. Juma 10, Maritha J. Kotze 11, Godfrey Lema 12, Jason H. Moore 13, Holly Mortensen 14, Thomas B. Nyambo 12, Sabah A. Omar 15, Kweli Powell 16, Gideon S. Pretorius 17, Michael W. Smith 18, Mahamadou A. Thera 9, Charles Wambebe 19, James L. Weber 20, Scott M. Williams 21
1 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Departments of Genetics and Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
2 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Present address: Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, 24306 Pl?n, Germany.
3 Independent researcher, Sharon, CT 06069, USA.
4 Department of History, University of California, Los Angeles, CA 90095, USA.
5 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Departments of Genetics and Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.; Dipartimento di Biologia ed Evoluzione, Università di Ferrara, 44100 Ferrara, Italy.
6 UMR 208, IRD-MNHN, Musée de l’Homme, 75116 Paris, France.
7 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Present address: Department of Internal Medicine, Ohio State University, Columbus, OH 43210, USA.
8 Ministère de la Recherche Scientifique et de l’Innovation, BP 1457, Yaoundé, Cameroon.
9 Malaria Research and Training Center, University of Bamako, Bamako, Mali.
10 Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, 15-13 Khartoum, Sudan.
11 Department of Pathology, Faculty of Health Sciences, University of Stellenbosch, Tygerberg 7505, South Africa.
12 Department of Biochemistry, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
13 Departments of Genetics and Community and Family Medicine, Dartmouth Medical School, Lebanon, NH 03756, USA.
14 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Present address: Office of Research and Development, National Center for Computational Toxicology, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
15 Kenya Medical Research Institute, Center for Biotechnology Research and Development, 54840-00200 Nairobi, Kenya.
16 Department of Biology, University of Maryland, College Park, MD 20742, USA.; Present address: College of Education, University of Maryland, College Park, MD 20742, USA.
17 Division of Human Genetics, Faculty of Health Sciences, University of Stellenbosch, Tygerberg 7505, South Africa.
18 Laboratory of Genomic Diversity, National Cancer Institute, Frederick, MD 21702, USA.
19 International Biomedical Research in Africa, Abuja, Nigeria.
20 Marshfield Clinic Research Foundation, Marshfield, WI 54449, USA.
21 Department of Molecular Physiology and Biophysics, Center for Human Genetics Research, Vanderbilt University, Nashville, TN 37232, USA.
* To whom correspondence should be addressed.
Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, 4 African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observe high levels of mixed ancestry in most populations, reflecting historic migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan-speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies.