In the most recent podcast we discussed how baby bats learn their calls from all the other bats in their crowded colonies. And we mentioned in passing that songbirds usually get tutored directory from their dads. So, how does that avian system work?

在最新发布的一期播客中，我们讨论了蝙蝠宝宝们是如何在拥挤的蝙蝠群中学习发声的。其中提到了，在通常情况下，鸣禽会直接从父亲那里得到指导。那么，在它们之间，这种‘学习’系统是如何运作的呢？

撰文/播音：克里斯多夫·利亚塔（Christopher Intagliata）

翻译：曲荟龙

审校：许楠

"At about 25 days, the father starts singing directly to the juvenile." David Mets, a geneticist at the University of California San Francisco. "That is the onset of what's called the sensory phase of learning. Where they incorporate information from their environment."

“在出生后25天左右，雄鸟便开始对向幼鸟鸣叫。”加州大学旧金山分校的遗传学家大卫·梅茨这样说，“这是学习过程中感知阶段的开始，在这一阶段中，幼鸟们从周围环境中获得信息。”

What Mets and his team wanted to know was how much of a baby bird's future musicality is influenced by that tutoring…an environmental factor…and how much is written in their genes. So they studied Bengalese finches.. which sing like this. < >

幼鸟的乐感，有多少源于雄鸟对其的指导，又有多少是受到环境因素的影响，还有多少是由其基因导致，这正是梅茨及其团队想要了解的问题。他们选取孟加拉雀作为研究对象，它们的鸣叫声是这样。

<雀鸣1 >

The tempo of that song appears to vary, according to a finch's genetics. So they tried training baby finches, with different genetic tendencies - fast, medium or slow singing - on a synthetic finch song, made from a library of different types of song syllables. "Tonal downward sweeps, you know. Or sort of broadband noisy ones, like sshhhh."

孟加拉雀鸣叫的节奏听起来有所不同，这取决于它们的基因。根据幼雀的基因谱，人类可以将它们分为快节奏、中等节奏和慢节奏三个不同的种类。实验团队尝试训练这些基因谱不同的幼雀来演奏一场雀类大合唱——这场大合唱包含着不同的音节。这其中有像吹口哨那样逐渐下降的音调，也有像“sshhhh”那样宽频的杂音。

But when baby finches with different genetic backgrounds were trained on the resulting tune < >, the training didn't stick. Instead, the greatest predictor of their singing tempo was the way their fathers sang—which they’d never heard. So their genes seemed to be in charge.

但是，这些遗传背景不同的幼雀，经过训练却无法演唱规定的“训练曲目”。而是它们父亲的鸣叫方式取代了遗传因素，成为了最能够预测它们鸣叫节奏的手段。而在（梅茨的）实验中，这些幼雀并没有听过其父亲是如何鸣叫的。因此，幼雀的基因似乎就是鸣叫方式的主要决定因素。

But then Mets flipped the experiment—exposing genetically similar birds to actual live birds that sang fast, medium, or slow. And that live training appears to have been compelling enough to override the influence of the birds' genetics. So that genetically identical chicks sang tunes fast < > medium < > or slow < >…depending what their tutor sang.

但随后梅茨又进行了一组实验——让基因谱相似的幼雀们分别和自然界中的雀类一同生活，这些雀的鸣叫节奏不同，有快有慢有中速。结果显示，生活训练的作用可以有力地覆盖掉基因对雀鸣方式的影响。因此，这些基因谱相似的幼雀虽然鸣叫的节奏有快有慢，但都和它们的‘导师’相同。

The results are in the Proceedings of the National Academy of Sciences. [David G. Mets and Michael S. Brainard, Genetic variation interacts with experience to determine interindividual differences in learned song]

本结果刊于在美国国家科学院的论文集中。[David G. Mets and Michael S. Brainard, Genetic variation interacts with experience to determine interindividual differences in learned song]

The study suggests that the right kind of schooling…or environmental influences… might be able to overcome 'baked in' genetic influence on certain traits. And Mets says this push-pull of nature versus nurture might hold true for humans, too.

研究表明适当的教育或环境也许能够克服“遗传信息”对某些性状的影响。梅茨表示这种先天因素和后天因素之间的相互作用也可能适用于人类。

"We're moving very rapidly into a period where genetic data is easier and easier to collect. And an understanding of these kinds of gene-environment push/pull interactions, and how they impact ultimate phenotypic outcomes, is going to be important in understanding things like cancer susceptibility." Because that too has both genetic and environmental factors.

“现如今，基因数据的收集变得越来越容易。我们可以了解基因和环境之间的促进/抑制作用，以及它们如何影响最终表型，这在研究癌症易感性等方面是很重要的。”因为癌症的发生也包括遗传和环境因素之间的相互作用。

But no word yet on whether the genetic influences of an off-tempo human father…can be conquered with enough training.

但对于后天足够的训练是否能够弥补先天的不足，现在仍然没有确定的说法。