生物谷報(bào)道：綜合大熊貓化石及現(xiàn)生種體型大小變化,、食物特化、種群數(shù)量急劇下降,、棲息地破碎化,、圈養(yǎng)種群繁殖衰退和竹子開花等多方面研究，傳統(tǒng)的觀點(diǎn)認(rèn)為大熊貓的瀕危是進(jìn)化歷程的必然,。記者今天從中國(guó)科學(xué)院動(dòng)物研究所了解到,，由該所研究員魏輔文領(lǐng)導(dǎo)的研究小組最新完成的一項(xiàng)研究成果表明，大熊貓并未走到進(jìn)化歷史的盡頭,，仍然具有進(jìn)化潛力,。該成果發(fā)表于近期出版的進(jìn)化生物學(xué)領(lǐng)域權(quán)威期刊《分子生物學(xué)與進(jìn)化》上。
魏輔文小組在中科院海外創(chuàng)新團(tuán)隊(duì)項(xiàng)目和國(guó)家杰出青年基金的資助下,，與四川省林業(yè)廳,、英國(guó)卡迪夫大學(xué)、西華師范大學(xué)等單位的專家合作,，采用群體遺傳學(xué)的研究方法,，對(duì)現(xiàn)存大熊貓種群遺傳多樣性與變異、種群遺傳結(jié)構(gòu)與基因流,、種群動(dòng)態(tài)歷史等問題進(jìn)行深入討論,。發(fā)現(xiàn)該物種現(xiàn)生種群仍保持較高的遺傳多樣性和長(zhǎng)期續(xù)存的進(jìn)化潛力，大熊貓?jiān)谀┐伪谙诤筮€經(jīng)歷了強(qiáng)烈的種群擴(kuò)張,，而現(xiàn)生種群的衰退僅始于幾千年前,。這一結(jié)果提示大熊貓種群的瀕危和中國(guó)歷史上人口不斷增長(zhǎng)所帶來(lái)的壓力密切相關(guān)。上述發(fā)現(xiàn)修正了長(zhǎng)久以來(lái)公眾對(duì)大熊貓前途命運(yùn)的認(rèn)識(shí),，表明大熊貓并非處于進(jìn)化歷史盡頭的孑遺物種,，而仍是具有進(jìn)化潛力的美麗生靈。大熊貓的瀕危由自身以外的因素造成,，而人類應(yīng)為其種群瀕危負(fù)有不可推卸的責(zé)任,。
大熊貓憨態(tài)可掬的外表、以竹為生的獨(dú)特食性,、不為人所知的生活習(xí)性等,，使它幾乎成為世界范圍內(nèi)最受關(guān)注的物種、世界自然保護(hù)的象征。近年來(lái),，我國(guó)野生大熊貓的調(diào)查結(jié)果顯示,，其棲息地質(zhì)量逐步改善，種群數(shù)量已有回升的良好勢(shì)頭,。這一方面表明我國(guó)政府所采取的一系列保護(hù)措施——如實(shí)施大熊貓棲息地保護(hù)工程、天然林保護(hù)工程和退耕還林工程,，建立大熊貓自然保護(hù)區(qū)網(wǎng)絡(luò)等——正日益凸現(xiàn)出其生態(tài)效益,；另一方面，也表明現(xiàn)生大熊貓種群仍保持勃勃生機(jī),，為其并未走到進(jìn)化歷史盡頭提供了佐證,。（科學(xué)時(shí)報(bào)）
原始出處:
MBE Advance Access originally published online on May 19, 2007
Molecular Biology and Evolution 2007 24(8):1801-1810; doi:10.1093/molbev/msm099
Genetic viability and population history of the giant panda, putting an end to the evolutionary dead-end
Baowei Zhang*, Ming Li*, Zejun Zhang*,, Benoît Goossens, Lifeng Zhu*, Shanning Zhang*, Jinchu Hu, Michael W. Bruford and Fuwen Wei*,
* Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, the Chinese Academy of Sciences, Haidian, Beijing, People's Republic of China
Biodiversity and Ecological Processes Group, School of Biosciences, Cardiff University, Cardiff, United Kingdom
Institute of Rare Animals and Plants, China West Normal Univeristy, Nanchong, Sichuan, People's Republic of China
Corresponding author: Fuwen Wei, Tel: +86-010-64807152, Fax: +86-010-64807099, E-mail: [email protected]
Received for publication November 26, 2006. Revision received April 10, 2007. Accepted for publication May 15, 2007.
The giant panda (Ailuropoda melanoleuca) is currently threatened by habitat loss, fragmentation and human persecution. Its dietary specialization, habitat isolation and reproductive constraints have led to a perception that this is a species at an ‘evolutionary dead-end’, destined for deterministic extinction in the modern world. Here, we examine this perception by a comprehensive investigation of its genetic diversity, population structure and demographic history across its geographic range. We present analysis of 655 base pairs of mitochondrial (mt) control region (CR) DNA and ten microsatellite loci for samples from its five extant mountain populations (Qinling, Minshan, Qionglai, Liangshan and Lesser Xiangling). Surprisingly, extant populations display average to high levels of CR and microsatellite diversity compared with other bear species. Genetic differentiation among populations was significant in most cases but was markedly higher between Qinling and the other mountain ranges, suggesting, minimally, that the Qinling population should comprise a separate management unit for conservation purposes. Recent demographic inference using microsatellite markers demonstrated a clear genetic signature for population decline starting several thousands years ago or even futher back in the past, and being accelerated and enhanced by the expansion of human populations. Importantly, these data suggest that the panda is not a species at an evolutionary ‘dead-end’, but in common with other large carnivores, has suffered demographically at the hands of human pressure. Conservation strategies should therefore focus on the restoration and protection of wild habitat and the maintenance of the currently substantial regional genetic diversity, through active management of disconnected populations.
Key Words: giant panda • genetic diversity • population structure • population demography • evolutionary dead-end
