當Gary Rosenberg博士15年前開始編譯一個海貝殼的在線數(shù)據(jù)庫的時候,，他根本沒有想象到他精心保存的記錄最終解決了一個持續(xù)了40年的進化爭論問題,。
??這個爭論包括海島規(guī)則的機制：在這個島上棲息的小型動物比它們在大陸上生活的近親體型進化得更大，而大型的動物則進化得更小,。九月即將發(fā)表在《生物地理學(xué)雜志》上的一篇名為《島嶼規(guī)則與深海動物體型進化》的論文中,，費城自然科學(xué)院自然歷史博物館的系統(tǒng)生物和進化中心的副院長Rosenberg和他的合著者利用他詳細的海螺數(shù)據(jù)庫將島嶼規(guī)則運用到深海動物身上。他們發(fā)現(xiàn)了一個相似的模式：當海螺統(tǒng)治深海的時候,，大型的海螺變得更小,，而小型的海螺則變得更大。
??Rosenberg表示：我建立Malacolog數(shù)據(jù)庫（西大西洋軟體動物物種數(shù)據(jù)庫）作為一種研究工具已經(jīng)許多年了,，這個數(shù)據(jù)庫歸納總結(jié)了軟體動物物種的名稱和分布情況,，但是，并沒有考慮到這個特殊的進化問題,。這就意味著輸入該系統(tǒng)的數(shù)據(jù)并不能下意識地偏向于這個結(jié)果,。這個Malacolog數(shù)據(jù)庫記錄了大西洋西部從格陵蘭島到南極洲的軟體動物物種。
??科學(xué)家們也對生活在這個與世隔絕的島嶼上的動物體型進化問題作出了幾個解釋：面積縮小,、天敵減少,、競爭削弱、資源限制,。而其中僅資源限制適用于深海動物,，我們都知道深海中可得的食物來源少于淺層海域，但是深海的面積卻大得多,。競爭者和動物天敵通常也不會到達這個小島,，但是深海的競爭和掠食卻很猛烈。關(guān)于這些因素的重要性還需要進一步地研究,，但是目前很清晰的是在動物體型的進化上，資源限制是一個關(guān)鍵的因素,。
英文原文：
Scientist’s persistence sheds light on marine science riddle
When he started compiling an online database of seashells 15 years ago, Dr. Gary Rosenberg did not envision that his meticulous record-keeping would eventually shed light on a 40-year-old evolutionary debate.
The debate involves the mechanism underlying the island rule: that small animals isolated on islands evolve to be larger than their mainland relatives, and large animals evolve to be smaller. In a paper to be published in September in the Journal of Biogeography, “The Island Rule and the Evolution of Body Size in the Deep Sea,” Rosenberg and his co-authors apply the island rule to deep-sea animals using Rosenberg’s detailed database of marine snails. They find a similar pattern: when species colonize the deep sea, large-bodied species become smaller and small-bodied species become larger.
“I’ve been building the Malacolog database for many years as a tool for research, summarizing information on the names and distributions of species of mollusks, but I had not anticipated asking this particular evolutionary question,” said Rosenberg, Vice President for the Center for Systematic Biology and Evolution at The Academy of Natural Sciences, Philadelphia’s natural history museum. “That means that the data entered in the system could not have been subconsciously biased toward this result. I hope there will be many more surprising results in the years to come.” The database Malacolog (www.data.acnatsci.org/wasp) documents species of mollusks in the Western Atlantic, from Greenland to Antarctica.
Scientists have suggested several explanations for the evolution of body size in animals isolated on islands: reduced area, fewer predators, less competition, and resource limitation. “Only resource limitation clearly applies to deep-sea animals,” said Rosenberg. “We know there is less food available in the deep sea than in shallow water, but the area of the deep sea is much larger. Also, the competitors and predators of a species often don’t reach an island, but competition and predation in the deep sea can be intense. A lot more study needs to be done on the relative importance of these factors, but clearly resource limitation is a key factor in the evolution of size.”
