原文網址：www.sciencedaily.com/releases/2015/09/150918180310.htm
'Tree of
life' for 2.3 million species released
包含230萬個物種的「生命之樹」
Large, open-access resource aims to be 'Wikipedia' for
evolutionary history
以成為演化史「維基百科」為目標的大型公開資源
A first draft of the
"tree of life" for the roughly 2.3 million named species of animals, plants,
fungi and microbes -- from platypuses to puffballs -- has been released.
首幅包含約230萬個已命名的動物、植物、真菌和微生物的生命之樹草圖已經公布，包括了從鴨嘴獸至馬勃菌(puffball)在內的種種生命。
A collaborative effort
among eleven institutions, the tree depicts the relationships among living
things as they diverged from one another over time, tracing back to the
beginning of life on Earth more than 3.5 billion years ago.
由11所研究機構合作建立而成的這棵生命之樹，呈現出從35億年前地球生命起源開始，隨著時間推進，生物逐漸從另一生物分歧出來而開枝散葉的過程中，彼此之間的關係。
Tens of thousands of
smaller trees have been published over the years for select branches of the
tree of life -- some containing upwards of 100,000 species -- but this is the
first time those results have been combined into a single tree that encompasses
all of life. The end result is a digital resource that available free online
for anyone to use or edit, much like a "Wikipedia" for evolutionary
trees.
在過去的數年間，科學界已經發表了數以萬計較小株，僅呈現特定分枝的生命之樹。雖然有些包含了多達100000種以上的生物，但這是第一次有人將這些成果全部合併，而繪出容納所有物種的單一生命樹。最終結果為在網路上公開，可讓任何人免費使用或者編輯的數位化資源，就像是維基百科的演化樹版本。
"This is the first real
attempt to connect the dots and put it all together," said principal
investigator Karen Cranston of Duke University. "Think of it as Version
1.0."
「這是科學家實際上首次嘗試將這些點全部連起來並拼湊出完整的圖像。」計畫主持人，杜克大學的Karen Cranston說，「可以將之視作為版本1.0。」
The current version of the tree
-- along with the underlying data and source code -- is available to browse and
download at https://tree.opentreeoflife.org.
It is also described in an
article appearing Sept. 18 in the Proceedings of the National
Academy of Sciences.
9月18日刊登於《美國國家科學院期刊》的文章中也會詳述這棵生命之樹。
Evolutionary trees,
branching diagrams that often look like a cross between a candelabra and a
subway map, aren't just for figuring out whether aardvarks are more closely
related to moles or manatees, or pinpointing a slime mold's closest cousins.
Understanding how the millions of species on Earth are related to one another
helps scientists discover new drugs, increase crop and livestock yields, and
trace the origins and spread of infectious diseases such as HIV, Ebola and
influenza.
演化樹是一種有許多分枝的圖表，往往看起來像是分枝眾多的燭臺和地鐵路線圖之間的混合體。它的用途不只是找出鼴鼠和海牛誰跟土豚的關係比較近；或者指出誰是粘菌關係最近的表親。瞭解地球上數以百萬計物種彼此之間的關聯，有助於科學家研發新型藥物、增加農業和畜牧業產量，並找出傳染性疾病，像是愛滋病、伊波拉病毒和流感的起源與散播路徑。
Rather than build the tree
of life from scratch, the researchers pieced it together by compiling thousands
of smaller chunks that had already been published online and merging them
together into a gigantic "supertree" that encompasses all named
species.
研究人員並非一點一滴地樹立起這棵大樹，而是收集數千條發表在網路上的枝幹，將它們拼拼湊湊，接合成這棵容納所有已命名物種的「神木」。
The initial draft is based
on nearly 500 smaller trees from previously published studies.
他們利用發表於過往研究中，將近500株的小型演化樹來建立最初的圖樣。
To map trees from different
sources to the branches and twigs of a single supertree, one of the biggest
challenges was simply accounting for the name changes, alternate names, common
misspellings and abbreviations for each species. The eastern red bat, for
example, is often listed under two scientific names, Lasiurus
borealis and Nycteris
borealis. Spiny anteaters once shared their scientific name with a
group of moray eels.
考量到每一個物種名字的變化、別名、常見拼字錯誤和縮寫，要從來自四面八方的資料繪製出這棵神木的一根分枝甚至末梢，便是一大挑戰。拿東方紅蝠(eastern red bat)為例，牠在學名上就有兩種稱呼，Lasiurus
borealis和Nycteris borealis。而針鼴則曾經與一種鯙類(海鱔)共用學名。
"Although a massive
undertaking in its own right, this draft tree of life represents only a first
step," the researchers wrote.
「儘管我們為此已嘔心瀝血，這幅生命之樹草圖仍然只是相當初步的成果。」研究人員寫道。
For one, only a tiny
fraction of published trees are digitally available.
原因之一是已發表的演化樹中，只有一小部份能以數位化的形式取得。
A survey of more than 7,500
phylogenetic studies published between 2000 and 2012 in more than 100 journals
found that only one out of six studies had deposited their data in a digital,
downloadable format that the researchers could use.
在調查了從2000至2012年發表在超過100種期刊中，7500篇以上有關親緣關係的研究後，他們發現當中大概只有六分之一有數位化他們的數據，成為可供其他研究人員下載的格式。
The vast majority of evolutionary
trees are published as PDFs and other image files that are impossible to enter
into a database or merge with other trees.
絕大部分的演化樹是以PDF或其他影像檔的格式發表，而這類格式並無法輸入資料庫或是合併至其餘演化樹。
"There's a pretty big
gap between the sum of what scientists know about how living things are
related, and what's actually available digitally," Cranston said.
「科學家全體對現存生物彼此之間關聯的所有相關知識中，能以數位化形式取得的部分實則少之又少。」Cranston說。
As a result, the
relationships depicted in some parts of the tree, such as the branches
representing the pea and sunflower families, don't always agree with expert
opinion.
因此，呈現在這棵生命之樹中的部分親緣關係，像是豌豆與向日葵家族所在分枝的樣貌，並非總是符合其他專家的意見。
Other parts of the tree,
particularly insects and microbes, remain elusive.
至於其他一些部分仍然混沌不清，尤其是代表昆蟲和微生物的分枝。
That's because even the
most popular online archive of raw genetic sequences -- from which many
evolutionary trees are built -- contains DNA data for less than five percent of
the tens of millions species estimated to exist on Earth.
即便是科學家在建構許多演化樹時最常使用的原始基因序列網路資料庫，其含有的DNA資料估計也不到現存於地球上的數千萬種生物中的5%。
"As important as
showing what we do know about relationships, this first tree of life is also
important in revealing what we don't know," said co-author Douglas Soltis
of the University of Florida.
「第一棵生命之樹的重要之處在於它顯現出我們對這些親緣關係所知多少，而同樣重要的是它也呈現了我們未知的部分。」共同作者，佛羅里達大學的Douglas Soltis說。
To help fill in the gaps,
the team is also developing software that will enable researchers to log on and
update and revise the tree as new data come in for the millions of species
still being named or discovered.
由於還有數百萬筆仍在命名或尚待發現的物種的新資料會來填補這些空缺，團隊也設計出可以讓其他研究人員登入、更新並持續審查這棵生命之樹的軟體。
"It's by no means
finished," Cranston said. "It's critically important to share data
for already-published and newly-published work if we want to improve the
tree."
「這絕不是個結束，」Cranston說，「若我們想要繼續改良並優化這棵生命之樹，至關重要的是分享已經發表的數據，以及新刊出的成果。」
"Twenty five years ago
people said this goal of huge trees was impossible," Soltis said.
"The Open Tree of Life is an important starting point that other
investigators can now refine and improve for decades to come."
「25年前人們會說要創建一株這麼雄偉的演化樹是痴人說夢，」Soltis說，「「開放的生命之樹」是個重要的開始，未來數十年其他研究人員將會繼續讓它變得更加完備且精確。」
This research was supported
by a three-year, $5.76 million grant from the U.S. National Science Foundation
(1208809).
美國國家科學基金會給予此研究3年總計576萬美元的贊助(編號：1208809)。
This circular
family tree of Earth's lifeforms is considered a first draft of the
3.5-billion-year history of how life evolved and diverged.
此幅呈現環形，包含所有地球生命的家族樹為首張草圖繪出35億年來，地球生命如何演化與分枝。
(Metazoa：動物；Archaea：古菌；Bacteria：細菌；Excavata：古蟲；Amoebozoa：變形蟲；SAR：SAR超類群；Archaeplastida：原始色素體生物(泛植物)；Fungi：真菌)
來源：opentreeoflife.org
引用自：Duke
University. "'Tree of life' for 2.3 million species released: Large,
open-access resource aims to be 'Wikipedia' for evolutionary history."
ScienceDaily. ScienceDaily, 18 September 2015.
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