人類為古代巨型哺乳類滅絕的元凶

原文網址：www.sciencedaily.com/releases/2015/08/150813104305.htm

Humans responsible for demise of gigantic ancient mammals

人類為古代巨型哺乳類滅絕的元凶

Early humans were the dominant cause of the extinction of a variety of species of giant beasts

早期人類為許多種巨型野獸滅絕的主因

Early humans were the dominant cause of the extinction of a variety of species of giant beasts, new research has revealed.

新的研究顯示早期人類為許多種巨型野獸滅絕的主因

Scientists at the universities of Exeter and Cambridge claim their research settles a prolonged debate over whether humankind or climate change was the dominant cause of the demise of massive creatures in the time of the sabretooth tiger, the woolly mammoth, the woolly rhino and the giant armadillo.

劍齒虎、真猛瑪象、披毛犀(woolly rhino)、巨犰狳以及其他同時代的巨型生物滅絕的主因究竟是人類或者氣候變遷？艾克斯特大學與劍橋大學的科學家主張他們的研究能解決這起歷時已久的爭議。

Known collectively as megafauna, most of the largest mammals ever to roam the earth were wiped out over the last 80,000 years, and were all extinct by 10,000 years ago.

曾漫步在地球上，這些合稱為巨型動物群(megafauna)的哺乳類巨獸在過去的8萬年間逐漸消失，並在1萬年前完全滅絕。

Lewis Bartlett, of the University of Exeter, led the research, which also involved the universities of Reading and Bristol and is published in the journal Ecography. He said cutting-edge statistical analysis had helped solve the mystery almost beyond dispute, concluding that man was the dominant force in wiping out the creatures, although climate change could also have played a lesser role.

此篇刊登在期刊《描述生態學》(Ecography.)上的研究由艾克斯特大學的Lewis Bartlett領導，包含了來自雷丁大學與布里斯托爾大學的學者。他說最尖端的統計分析技術近乎完全解開了這道謎題。結論是，人類就是這些生物消亡的主要推手，雖然氣候變遷可能在其中扮演了次要角色。

The researchers ran thousands of scenarios which mapped the windows of time in which each species is known to have become extinct, and humans are known to have arrived on different continents or islands. This was compared against climate reconstructions for the last 90,000 years.

研究人員統計分析了數千筆個別物種滅絕的時段，以及人類到達不同的大陸或島嶼的時間，並將結果與過去9萬年來的氣候重建結果互相比對。

Examining different regions of the world across these scenarios, they found coincidences of human spread and species extinction which illustrate that man was the main agent causing the demise, with climate change exacerbating the number of extinctions. However, in certain regions of the world -- mainly in Asia -- they found patterns which patterns were broadly unaccounted for by either of these two drivers, and called for renewed focus on these neglected areas for further study.

在檢視了世界各地不同區域的情況之後，他們發現人類擴張與物種滅絕的時間相當雷同，顯示人類為物種滅絕的主因，而氣候變遷則導致了滅亡物種的數目增加。然而，在世界上的某些地區，主要位於亞洲，他們發現大部分物種滅亡的模式並不能以這兩種趨動因子的變化模式來解釋，因此他們認為之後的研究需要進一步聚焦在這些之前未受重視的區域。

Lewis Bartlett, a researcher from the University of Exeter's Centre for Ecology and Conservation, said: "As far as we are concerned, this research is the nail in the coffin of this 50-year debate -- humans were the dominant cause of the extinction of megafauna. What we don't know is what it was about these early settlers that caused this demise. Were they killing them for food, was it early use of fire or were they driven out of their habitats? Our analysis doesn't differentiate, but we can say that it was caused by human activity more than by climate change. It debunks the myth of early humans living in harmony with nature."

艾克斯特大學生態與保育中心的研究員Lewis Bartlett說：「就我們來看，這篇研究終於將這件長達50年的爭議蓋棺論定-人類就是巨型動物群滅亡的主因。但我們所不知道的是這些早期的移民者究竟是如何造成牠們的滅亡。他們是為了食物而獵殺牠們嗎？還是因為早期人類開始用火的影響？或者他們將這些巨獸驅離出牠們原本的棲地？我們的研究無法辨認孰是孰非，但我們可以很肯定地說人類活動的影響比氣候變遷要大得多。而這也破除了早期人類與大自然和諧共處的迷思。」

Dr Andrea Manica, of Cambridge University, was lead supervisor on the paper. He said: "Whilst our models explain very well the timing and extent of extinctions for most of the world, mainland Asia remains a mystery. According to the fossil record, that region suffered very low rates of extinctions. Understanding why megafauna in mainland Asia is so resilient is the next big question."

劍橋大學的Andrea Manica是這篇論文的主要指導教授。他說：「雖然我們的模型能夠成功地解釋世界上大部分地區的滅絕事件的發生時間以及規模大小，但對亞洲本土卻起不了作用。亞洲本土的巨型動物群為何有如此強韌的適應能力將會是下一個重要的問題。」

引用自：University of Exeter. "Humans responsible for demise of gigantic ancient mammals: Early humans were the dominant cause of the extinction of a variety of species of giant beasts." ScienceDaily. ScienceDaily, 13 August 2015.