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How did zebras get their stripes? It's hard to get a black-and-white
answer.
斑马身上的条纹是如何形成的?我们很难得到确切的答案。
Some scientists say the stripes are a form of camouflage thatprotects
zebras from hungry lions. Others say they're key tozebra mating rituals. Just
last year, researchers publishedresearch suggesting that the stripes repel
biting flies, thusprotecting the animals from diseases flies sometimes
carry.
有些科学家认为，条纹是一种伪装的形式，保护斑马免落狮口。另一些科学家则认为，条纹在斑马的求偶仪式中起到关键作用。2014年，有研究人员发表研究称，条纹能够赶走苍蝇，保护斑马远离苍蝇经常传播的疾病。
But a peculiar new study offers yet another possible explanation: the
stripes help the zebras staycool in their sometimes sweltering habitats.
一项特殊新研究提供了另一种可能的解释：斑马的栖息地有时会变得闷热难耐，条纹能助它们保持凉爽。
"We discovered that temperature is an important predictor of how stripy
plains zebra are," Dr.Brenda Larison, an assistant researcher at the University
of California, Los Angeles and the study'slead author, told The Huffington Post
in an email. "Zebra in areas with seasonal cold temperaturesare less stripy than
those in areas with sustained warm temperatures."
“我们发现，温度差异是决定平原斑马条纹的一个重要因素，”这项研究报告的主要作者，美国加州大学洛杉矶分校助理研究员布伦达·拉尔松博士在写给《赫芬顿邮报》的一封电子邮件中说，“季节性低温地区的斑马，条纹比气候持续温暖地区的斑马要少。”
For the study, the researchers analyzed variations in the stripes seen in
plains zebras at 16 sitesin Africa. The researchers then examined the
relationship between the stripe patterns and 29environmental variables,
including climate to predation to biting flies.
关于这项研究，研究人员对非洲16个地区的平原斑马条纹变化进行了分析。他们然后还研究了这些条纹图案与29种环境变量之间的关系，包括气候、捕食和苍蝇叮咬等。
What did the analysis show? The extent of striping was correlated more
closely with hot weatherthan with other environmental variables. In other words,
the hotter their habitat the more stripeszebras tended to have.
分析说明了什么?相比其它环境变量而言，条纹的覆盖程度与热气候关系更紧密。换句话说，栖息地越热，斑马条纹就越多。
One hypothesis for the correlation is that bold black and white stripes
cool zebras by creatingconvection currents in the air around the animals'
bodies. That is, air moves faster over sunlight-absorbing black stripes and
slower over white stripes to create cooling airflow, NationalGeographic
reported.
《国家地理》杂志报道称，此种关联的一种假说认为，醒目的黑白条纹能让斑马身体周围的空气产生对流，从而达到冷却效果。也就是说，空气在吸收阳光的黑色条纹上流动得快，而在白色条纹上流动得慢，这样就会形成冷却气流。
Indeed, preliminary observations using a digital thermometer gun showed
that grazing zebrasmaintain a significantly lower surface body temperature (84.6
degrees Fahrenheit) than nearbyantelopes that are similar in size but have brown
coats (90.5 degrees).
的确如此，数字式测温枪的初步观察结果表明，牧场上斑马的体表温度(84.6华氏度)与附近同等大小、褐色毛皮的羚羊(90.5华氏度)相比，明显较低。
2020207_091333_1.jpg
But this doesn't mean the zebra stripes mystery has finally been solved,
according to Larison.
但拉尔松认为，这并不意味着斑马条纹的谜底被最终揭开。
"We need to give all the hypotheses for zebra striping serious
consideration," she said in theemail. "We don't see any of the hypotheses as
being out of the running yet and there is no reasonto think there has to be just
one answer. Multiple functions of a trait are not unheard of."
“我们需要严肃对待关于斑马条纹的所有假说，”她在邮件中说，“目前尚无法断定哪一条假说说不通，也没有任何理由表明答案只有一个。一种动物的特性具有多种功能的例子此前也并非未听说过。”
The study was published in the journal Royal Society Open Science.
这项研究发表在《皇家学会开放科学》杂志上。
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发表于 2016-7-10 18:17:12