霍比特人曾经是高大的人种，然后

常年生活在岛上可能会产生奇怪的影响。在塞浦路斯，河马体形逐渐缩小到海狮的大小。在印度尼西亚的弗洛雷斯，已绝种的大象骸骨显示其体重不超过大型的猪，但老鼠与猫一样大。所有这些都是所谓的“岛屿效应”的例子——当食物和食肉动物稀缺时，大型动物会萎缩而小型动物会膨胀。但是没有人能确定它是否足以解释弗洛雷斯最著名的现象：在6万至10万年前曾经生活在岛上的人类的一个分支，身高约1米左右的霍比特人。

Now, genetic evidence from modern pygmies on Flores—who are unrelated to the hobbit—confirms that humans, too, are subject to so-called island dwarfing. An international team reports this week in Science that Flores pygmies differ from their closest relatives on New Guinea and in East Asia in carrying more gene variants that promote short stature. The genetic differences testify to recent evolution—the island rule at work. And they imply that the same force gave the hobbit its short stature, the authors say.

现在，来自弗洛雷斯的现代俾格米人的遗传证据——与霍比特人无关——证实人类也受到所谓的岛屿矮化的影响。一支国际联合科研团队本周在Science杂志上报告说，弗洛雷斯俾格米人与他们在新几内亚和东亚的最近支的亲戚不同，他们的基因存在着更多的变异细节导致身材矮小。遗传差异表明了晚近的进化力量——岛屿效应在起作用。作者说，他们倾向于认为同样的力量使霍比特人的身材矮小。

"Flores is a magical place where things go and get small," says population geneticist Joshua Akey at Princeton University, a co-author of the study. "This is the only example in the world where insular dwarfism has arisen twice in hominins."

“弗洛雷斯是一个神奇的地方，那里的东西都会变得越来越小”，共同作者、普林斯顿大学的人类遗传学家Joshua Akey说 ，“在一座岛屿上出现两支侏儒化人种，这是世界上已知绝无仅有的一例。”

Princeton postdoc Serena Tucci set out to study the Rampasasa pygmies of Flores, who average just 145 centimeters tall. Famed Indonesian paleoanthropologist Teuku Jacob, now deceased, had controversially proposed that the Rampasasa people inherited some traits from the hobbit, whom he thought was a modern human. To explore the pygmies' ancestry, Tucci and her then-adviser, Ed Green of the University of California (UC), Santa Cruz, traveled to Flores. With the pygmies' permission, they began a "model" collaboration with Indonesian researchers, says molecular biologist and co-author Herawati Sudoyo of the Eijkman Institute for Molecular Biology in Jakarta. Her colleagues gathered spit and blood from 32 people and extracted the DNA. Then, Eijkman researcher Gludhug Purnomo hand-carried samples to Green's lab, where he helped sequence 2.5 million single nucleotide polymorphisms, or alleles, in every individual, plus 10 complete genomes.

普林斯顿博士后Serena Tucci 一直研究着弗洛雷斯的Rampasasa 俾格米人，他们的平均身高只有145厘米。现已去世的，著名的印度尼西亚古人类学家Teuku Jacob，曾提出有争议地观点，认为Rampasasa人继承了霍比特人的一些特征，他认为后者也是现代人的一支。为了探索俾格米的祖先，Tucci和她当时的顾问，加州大学圣克鲁兹分校的Ed Green，前往弗洛雷斯。在雅加达Eijkman分子生物学研究所的分子生物学家和共同作者Herawati Sudoyo的帮助下，经过俾格米人的同意，他们开始与印尼的研究人员进行合作，收集了当地32位俾格米成员的唾液和血液样本。然后，Eijkman的研究员Gludhug Purnomo将样品运送到Green的实验室提取DNA。科学家在那里对每个个体的250万个单核苷酸多态性等位基因进行测序。

The team found no trace of archaic DNA that could be from the hobbit. Instead, the pygmies were most closely related to other East Asians. The DNA suggested that their ancestors came to Flores in several waves: in the past 50,000 years or so, when modern humans first reached Melanesia; and in the past 5000 years, when settlers came from both East Asia and New Guinea.

该团队没有发现可能来自霍比特人的古老DNA痕迹。相反，俾格米人与其他东亚人关系最密切。DNA表明他们的祖先通过几波迁徙来到弗洛雷斯：5万年前左右，现代人类首次到达美拉尼西亚;过去的5000年里，定居者来自东亚和新几内亚。

The pygmies' genomes also reflect an environmental shift. They carry an ancient version of a gene that encodes enzymes to break down fatty acids in meat and seafood. It suggests their ancestors underwent a "big shift in diet" after reaching Flores, perhaps eating pygmy elephants or marine foods, says population geneticist Rasmus Nielsen of UC Berkeley, who was not part of the study.

俾格米人的基因组也反映了环境的变迁。他们携带了古老版本的基因，可以编码特殊的酶来分解肉类和海鲜中的脂肪酸。加州大学伯克利分校的人口遗传学家Rasmus Nielsen 说，这表明他们的祖先在到达弗洛雷斯之后经历了“饮食习惯的巨大转变”。

The pygmies' genomes are also rich in alleles that data from the UK Biobank have linked to short stature. Other East Asians have the same height-reducing alleles, but at much lower frequencies. This suggests natural selection favored existing genes for shortness while the pygmies' ancestors were on Flores. "We can't say for sure that they got shorter on Flores, but what makes this convincing is they're comparing the Flores population to other East Asian populations of similar ancestry," says population geneticist Iain Mathieson of the University of Pennsylvania.

通过与英国生物银行的数据进行比较，我们知道俾格米人的基因组中存在多组与身材矮小相关的等位基因。其他东亚人具有类似基因的频率要低得多。这表明自然选择有利于现有的基因。宾夕法尼亚大学的人类遗传学家Iain Mathieson说：“我们不能肯定地说他们来到弗洛雷斯后就变得矮小了，但把他们与其他类似血统的东亚人群进行比较，似乎得到了令人信服的结论。”

The discovery fits with a recent study suggesting evolution also favored short stature in people on the Andaman Islands, Green says. Such selection on islands boosts the theory that the hobbit, too, was once a taller species, who dwindled in height over millennia on Flores.

Green说，这一发现符合最近的一项研究，那项研究表明，安达曼群岛岛民矮小的身材在自然选择中有利。岛屿上的这一现象支持了这样的理论：霍比特人曾经是更高大的人种，当他们在弗洛雷斯生活了数千年之后，变得更加矮小了。

"If it can happen in hippos, it can happen in humans," Tucci says. "Humans are not as special as we think. This shows we evolve like all other animals."

“如果它可能发生在河马中，它也可能发生在人类身上，”Tucci说，“人类并不像我们想象的那么特别。我们遵循像所有其他动物一样的进化路径。”