英國斯特拉斯克萊德(Strathclyde)大學的科學家表示,透過殘留在鹿屍體上的人體DNA,現在已可追查出盜獵者。
他們的研究是有史以來第一次成功地從動物屍體上取得人體DNA的圖譜。科學家正在探索,可否將此鑑定方法應用在盜獵鹿以外的其他動物盜獵者。
斯特拉斯克萊德大學應用化學系法醫學中心的研究人員Shanan Tobe博士說,「我們取得非常低量的DNA,而這可能會是解決野生動物犯罪的一大突破。它不僅可以協助抓到現有的盜獵者,也可以嚇止其他不肖人士。」
由於盜獵行為通常發生在偏遠的地區,而且常常是在事件發生過後一段時間才會被發現,因此不論是鹿、犀牛或是大象等等大型野生動物的盜獵事件,都很難辨認出其盜獵者。
盜獵者分解動物屍體時通常會留下些許物證,而其中必然會殘留少許人類DNA。
不過,Tobe表示:「由於物證本質的關係,盜獵行為很難調查和起訴。因為在特定季節獵殺鹿是合法的,加上只從屍身無法辨別牠是否死於盜獵,使得盜獵鹿的犯罪調查困難重重。」
Tobe與一位蘇格蘭警務處的法醫學家Jim Govan一同進行研究如何採集利用少量的DNA辯認出盜獵者身分的檢驗方法。他們是從合法宰殺的10隻鹿的腿部取得DNA樣本的,雖然這些鹿原本在寒冷等極端嚴苛的環境下生存不易,不過,研究人員聲明,「於研究中所使用的樣本都是從每年度採獵的鹿群中取得,沒有任何動物因此研究而受傷害。」。
參與宰殺這些鹿的志工提供了本身的DNA,讓法醫專家們檢驗並比對,其比對檢查結果可以對應出宰殺哪隻鹿的志工是哪位。科學家表示,「用這種方法取得的DNA圖譜,和隨機從人群中取得DNA相同的機率,比十億分之一還低。」(編註:意謂此方法非常準確,辨識度高)
科學家說,他們的方法也可以用於其他野生動物盜獵的證據上。他們可以從羽毛、蛋、捕獸陷阱或圈套等具有證據性的物質中,檢測出DNA。
蘇格蘭環境與氣候變遷部長Stewart Stevenson表示:「我很高興有這樣的進展,顯示出蘇格蘭在尖端科學上的領先地位。」「藉由檢測動物屍體上殘留的人體DNA,讓執法者有更多的工具來保護野生動物免於盜獵的傷害。我希望此檢驗方法可以更廣泛地應用於追蹤盜獵鹿群的非法活動。」
本研究的資金有一半以上,是來自蘇格蘭自然襲產署負責的「打擊野生動物犯罪夥伴計畫」(Partnership for Action Against Wildlife Crime, Scotland)。其餘的資金則來自「英國射擊和保育協會」、英國愛鹿協會和蘇格蘭愛鹿委員會,該委員會現已是蘇格蘭自然襲產署轄下機構。
For the first time, suspected poachers can now be tracked through tests for traces of human DNA on deer remains, according to scientists at the University of Strathclyde in Glasgow and the Scottish Police.
Their research is the first time that human DNA profiles have been obtained successfully from an animal carcass. The scientists are exploring the method's potential for identifying poachers of animals other than deer.
"Our research has picked up DNA at very low levels and could be a significant breakthrough in wildlife crime," said Dr. Shanan Tobe, a research fellow in the Centre for Forensic Science in Strathclyde's Department of Pure and Applied Chemistry.
"It could not only help to catch existing poachers but could also act as a deterrent to others," he said.
Identifying poachers of wildlife - whether deer or larger animals such as rhino or elephants - can be problematic, as the crimes are often committed in remote areas and are not discovered until sometime after the event.
Poachers' practice of disassembling a carcass often means that little physical evidence, and consequently little human DNA, is left behind.
"Poaching can be extremely difficult to investigate and prosecute owing to the nature of the evidence available," said Dr. Tobe. "There are particular problems with deer poaching because deer can be legally hunted in season and identifying deer alone would not show whether or not they had been killed in the course of poaching."
Dr. Tobe worked with Jim Govan, a forensic scientist with the Scottish Police Services Authority, to develop a method that can pick up low levels of DNA and identify poachers.
The researchers obtained DNA samples from the legs of 10 deer which had been legally culled as deer are in the UK under freezing and other extreme conditions.
"All deer samples used in the study were obtained from deer as part of an annual cull. No animals were harmed for the purpose of the research," the University of Strathclyde said in a statement announcing the research results.
The forensic scientists examined the deer carcasses for matches of DNA provided by volunteers who had taken part in the cull. The tests yielded results that could be matched back to the volunteer hunter of each deer.
The chances of the DNA profiles picked up by this method being randomly found within the population would be less than one in a billion, the scientists said.
They say their method also could be used on other evidence in wildlife crime. They could test such evidentiary materials such as feathers, eggs, snares or traps for DNA.
Scottish Minister for Environment and Climate Change Stewart Stevenson said, "I welcome this development which demonstrates Scotland is at the forefront of the application of this cutting-edge science."
"The ability to test for the remains of human DNA on animal carcasses, gives law enforcers more tools to protect our wildlife from criminal activity," said Stevenson. "I look forward to hearing more about how this development can be used practically in tackling the illegal activity of deer poaching."
More than half of the funding for the research came from Partnership for Action Against Wildlife Crime, Scotland which is managed by Scottish Natural Heritage.
The remaining funds came from the British Association for Shooting & Conservation, the British Deer Society and the Deer Commission for Scotland, which is now part of Scottish Natural Heritage.
The research paper, "Recovery of human DNA profiles from poached deer remains: A feasibility study," is published in the journal "Science and Justice."