当Gary Rosenberg博士15年前开始编译一个海贝壳的在线数据库的时候，他根本没有想象到他精心保存的记录最终解决了一个持续了40年的进化争论问题。
??这个争论包括海岛规则的机制：在这个岛上栖息的小型动物比它们在大陆上生活的近亲体型进化得更大，而大型的动物则进化得更小。九月即将发表在《生物地理学杂志》上的一篇名为《岛屿规则与深海动物体型进化》的论文中，费城自然科学院自然历史博物馆的系统生物和进化中心的副院长Rosenberg和他的合著者利用他详细的海螺数据库将岛屿规则运用到深海动物身上。他们发现了一个相似的模式：当海螺统治深海的时候，大型的海螺变得更小，而小型的海螺则变得更大。
??Rosenberg表示：我建立Malacolog数据库（西大西洋软体动物物种数据库）作为一种研究工具已经许多年了，这个数据库归纳总结了软体动物物种的名称和分布情况，但是，并没有考虑到这个特殊的进化问题。这就意味着输入该系统的数据并不能下意识地偏向于这个结果。这个Malacolog数据库记录了大西洋西部从格陵兰岛到南极洲的软体动物物种。
??科学家们也对生活在这个与世隔绝的岛屿上的动物体型进化问题作出了几个解释：面积缩小、天敌减少、竞争削弱、资源限制。而其中仅资源限制适用于深海动物，我们都知道深海中可得的食物来源少于浅层海域，但是深海的面积却大得多。竞争者和动物天敌通常也不会到达这个小岛，但是深海的竞争和掠食却很猛烈。关于这些因素的重要性还需要进一步地研究，但是目前很清晰的是在动物体型的进化上，资源限制是一个关键的因素。
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.”
