我們是外星人再一章 ~ 跟恩師說的 一樣，演化並不是人種唯一的來源！ ~

美國研究驚人新發現　顛覆鳥類演化史
更新日期:2008/06/27 13:20 楊玫寧

（法新社華盛頓二十六日電） 美國研究人員今天指出，一項五年計劃已顛覆科學界對鳥類演化的見解，由由於研究結果驚人，如今教科書甚至可能必須改寫。研究主要撰寫人，伊利諾州芝加哥菲爾德博物館的芮迪及一名同僚說：「藉由這項研究，我們獲知兩件大事。」「第一，外貌不足信，外貌或是行為相似的鳥類不見得互有關連；第二，許多鳥類分類以及有關演化關係的傳統見解大錯特錯。」這項歷年來最大規模的鳥類遺傳學研究，結果包羅萬象，數十種鳥類命名如今將必需正名。這項研究報告將刊登在美國「科學」雜誌。 這項「早期鳥類聚集族譜研究計劃」調查了所有現存主要鳥類的演化史，且已針對約一百六十九種鳥類中每一種的19個不同DNA部位排序，建立和分析了三十二千個鹼基（Kilobases）資料組。 在分子生物學上，千個鹼基是DNA片段長度單位，代表一千個DNA鹼基對（base pair）。 鳥類會不斷地適應於新環境是這個研究小組的新發現之一，舉例來說，紅鶴和鷿虒並不是由其他水鳥演化而來，現今棲息在陸地上的鳥類也非自其他陸鳥演化而來，例如杜鵑鳥。其他與當今科學界見解大相逕庭的發現為，白天活動的蜂鳥演化自夜行的歐夜鷹，獵鷹與隼和老鷹沒有關連，飛行速度很快的海鳥也與鵜鶘和其他水鳥無關。

精采原文：
http://www.sciencemag.org/cgi/content/abstract/320/5884/1763
Science 27 June 2008: Vol. 320. no. 5884, pp. 1763 - 1768
DOI: 10.1126/science.1157704

A Phylogenomic Study of Birds Reveals Their Evolutionary History

Deep avian evolutionary relationships have been difficult to resolve as a result of a putative explosive radiation. Our study examined 32 kilobases of aligned nuclear DNA sequences from 19 independent loci for 169 species, representing all major extant groups, and recovered a robust phylogeny from a genome-wide signal supported by multiple analytical methods. We documented well-supported, previously unrecognized interordinal relationships (such as a sister relationship between passerines and parrots) and corroborated previously contentious groupings (such as flamingos and grebes). Our conclusions challenge current classifications and alter our understanding of trait evolution; for example, some diurnal birds evolved from nocturnal ancestors. Our results provide a valuable resource for phylogenetic and comparative studies in birds.

1. Zoology Department, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA.
2. Department of Zoology, University of Florida, Gainesville, FL 32611, USA.
3. Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.
4. Department of Science and Technology–National Research Foundation Centre of Excellence at the Percy FitzPatrick Institute, Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa.
5. Department of Vertebrate Zoology, Smithsonian Institution, 4210 Silver Hill Road, Suitland, MD 20746, USA.
6. Behavior, Ecology, Evolution, and Systematics Program, University of Maryland, College Park, MD 20742, USA.
7. Pepperwood Way, San Jose, CA 95124, USA.
8. Museum of Natural Science, 119 Foster Hall, Louisiana State University, Baton Rouge, LA 70803, USA.
9. Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA.
10. Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
11. Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131, USA.
* These authors contributed equally to this work.
* To whom correspondence should be addressed. E-mail: rkimball@ufl.edu