教给学生他们自己时代的生物学

“Eventhemostimaginativeandrigoroussciencebearsthestampofthehistoricalcircumstancesofitsmaking.”...

历史学家研究陈年往事的起因和结果，也会假想事情的另一种可能。比如，如果不列颠在欧洲的一战中作壁上观，可能会发生什么呢？科学史家们也会提出类似的假设性问题，而结果可能相当有益。

说说遗传学吧。去年学界见证了经久不息的庆祝孟德尔（Gregor Mendel）豌豆杂交实验发表150周年的活动。孟德尔的实验在全世界的生物学课程中都是核心内容。相反，牛津大学林纳克教授（Linacre professor，牛津大学的一种教授职位）韦尔登（W. F. R. Weldon ）针对孟德尔理论的批评意见就仅仅成为了书底的注脚。

自1902年开始，韦尔登的观点使他陷入了跟越来越气急败坏的孟德尔追随者们的争吵中。在基本原则上，孟德尔主义者坚信遗传因子（后来被叫做基因）决定了有机体的可见性状，然而，韦尔登看到了遗传的上下文——发育和环境的因素——以被孟德尔忽略了的方式同样重要地影响性状的变化。孟德尔主义者赢了——得益于韦尔登尚未完整发表他的观点便于1906年突然离世——从此遗传学的教学着重强调基因的主导作用。

问题是，孟德尔主义的“基因论”的进展在21世纪的生物学中越发显得落伍了。批评意见认为，如果我们想要变现基因组时代的潜能的话，就必须找到更符合变化迅速的生物学现实情况的概念和词汇。这一点在教育界尤为重要，因为在那里，从简单例子习得的观念反而使人更加相信过时的基因决定论里所说的基因的力量。

但是，假如孟德尔主义从一开始就从未取得遗传学的统治地位，那会怎样呢？假如韦尔登的远见在那场历史论战中获胜，他的相互作用论，与他关于真实有机体的真实性状是如此多变的生动意识结合起来（从来不是非黄即绿，非圆即皱，或者任何其它孟德尔式二元性状）成为了遗传学的核心理论，又会怎样呢？这就是我和我的同事们想要进行的实验。

在最近的一个为期两年的项目中，我们将大学生的教材修改成假设1906年左右生物学采纳了韦尔登而非孟德尔理论框架后可能的样子。这些学生学到的遗传学基础而普遍地跟发育和环境紧密相关。基因没有按照现行观念里遗传“本来的样子”来展示给学生，而是贬谪为任何其它不可忽视的次要因素。比如说，他们会学到尽管基因可以直接影响心脏，也会影响血压，然而，身体的活动水平或别的指标本身却是经常受非遗传因子（比如吸烟）影响的。在这样子混淆后，我们会问他们，哪个基因会引起心脏疾病吗？从效果来说，这份篡改了的教材是想要把原来教学中处于边缘地位的东西放到中心位置，把原来在中心的东西边缘化。

我们的被试组是二年级的人类学本科生，对照组则是按照传统框架教学的生物学一年级学生。我们的确观察到了差异，这些按照韦尔登框架教学的学生更不信基因决定论，而且，我猜他们更容易理解现代遗传学的精妙。（这个差异是统计显著的，但我不敢据此推测太多，毕竟参加实验的人数有限，而且两个组的人数也不一致。我也留意到，正是韦尔登最早注意到了孟德尔在过分夸大统计显著性上的问题。）

有了这样的实验——将历史陈事带进理学的课堂——科学往事能够启示甚至促进科学的未来。反过来，这也揭示了合作研究更广阔的前景。为了推动科学知识的进步，历史学家和科学哲学家们应该和科学家们紧密合作，不是说要真的跑到实验室去，而是通过交流渠道来合作。研究那些被忽略了的现象以及过早终止了的论战也许就可以为创造新的科学观念激发灵感。

那孟德尔怎么办呢？有人可能会抱怨说，这样子挖他在遗传学课程里的光辉大殿的墙脚可是个很糟糕的纪念礼物。依我说，这些碎碎念，虽然可以理解，但肯定是不对的。若是我们想纪念孟德尔，那我们就应该严肃地，按照历史原样的，不落入后来教条的孟德尔主义窠臼地解读他。我们要学习孟德尔，然后让他留在他自己的时代。同样地，我们也该给我们的生物学学生跟得上21世纪脚步的遗传学教程，让他们也成为他们时代的一部分。如果我们教他们孟德尔，我们不应该让他们目瞪口呆地惊叹孟德尔的重大发现，而是帮助他们领略到即使是最为富于想象力和理性力量的科学——孟德尔在这两方面都是一流的——都会被盖上它所处于的时代的历史环境的戳印。从往日科学学习此经验，在今日便当自觉和自省。

翻译：郭子骁

原文：[b]Gregory RadickTeach students the biology of their time

Historians study the causes and consequences of past events, but also consider alternative scenarios. What might have happened, for example, if Britain had stayed out of the war in Europe in 1914? Science historians also ask such counterfactual questions, andthe results can be surprisingly instructive.

Take genetics. The past year has seen prolonged celebrations of the work of Gregor Mendel, linked to the 150th anniversary of the paper that reported his experiments with hybrid peas.Mendel’s experiments are central to biology curricula across the world. Bycontrast, the criticisms levelled at Mendel’s ideas by W. F. R. Weldon, Linacre professor at the University of Oxford, UK, are a footnote.

From 1902, Weldon’s views brought him into increasingly bad-tempered conflict with Mendel’s followers. In basic terms, the Mendel­i­­­­ans believed that inherited factors (later called ‘genes’) determine the visible characters of an organism, whereas Weldon sawcontext — developmental and environmental — as being justas important, with its influence making characters variable in ways thatMendelians ignored. The Mendelians won — helped by Weldon’s suddendeath in 1906, before he published his ideas fully — and the teachingof genetics has emphasized the primacy of the gene ever since.

The problem is that the Mendelian ‘genes for’ approach is increasingly seen as out of step with twenty-first-century biology. If we are to realize the potential of the genomic age, critics say, we must find new concepts and language better matched to variable biological reality. This is important in education, where the reliance on simple examples may even promote an outmoded determinism about the power of genes.

But what if Mendelism had never come to dominate genetics in the first place? What if Weldon’s perspective had emergedas the winner in that historical battle, and his interactionism, allied to hisvivid sense of how variable the real characters of real organisms are (neverjust yellow or green, round or wrinkled, or any other Mendelian binary), had become the core of the subject? This is where I, and colleagues, have tried to run an experiment.

In a recent two-year project, we taught university students a curriculum that was altered to reflect what genetics text books might be like now if biology circa 1906 had taken the Weldonian rather than the Mendelian route. These students encountered genetics as funda­mentally tied to development and environment. Genes were not presented to them as what inheritance is ‘really about’, with everything else relegated to ignorable supporting roles. For example, they were taught that although genes can affectthe heart directly, they also affect blood pressure, the body’s activity levels and other influential factors, themselves often influenced by non-geneticfactors (such as smoking). Where in this tangle, we ask them, is a gene for heart disease? In effect, this revised curriculum seeks to take what is peripheral inthe existing teaching of genetics and make it central, and to make what iscentral peripheral.

Our experimental group consisted of second-year humanities undergraduates. First-year biologists, who were taughtthe conventional approach, acted as our control. We saw a difference — those students taught the Weldon way emerged as lessbelieving of genetic determinism, and, I suspect, better prepared to understand the subtleties of modern genetics. (The difference was statistically significant, but I hesitate to make much of that, given that numbers were smalland there were differences between the groups. I am mindful, too, that it was Weldon who first drew attention to Mendel’s own problems with exaggerated statistics.)

With such experiments — bringing insights from the archive into the science classroom — the scientific past can informand maybe even improve the scientific future. In turn, they suggest a broader vision of collaboration. To advance scientific knowledge, historians and philosophers of science should work in close proximity to scientists, not actually in the lab but right down the corridor. Then, investigations into neglected phenomena and debates that were shut down too soon might provide the spark to serve creative science.

What of Mendel? Some might complain that itis a poor anniversary gift to jettison him from his place of honour in the genetics curriculum. Let me suggest that this grumbling, although understandable, is misguided. If we want to honour Mendel, then let us read him seriously, which is to say historically, without back-projecting the doctrinaire Mendelism that came later. Study Mendel, but let him be part of his time.

Likewise, let our biology students be part of their time, by giving them a genetics curriculum fit for the twenty-first century. If we teach them about Mendel, we should do so not to fill them with slack-jawed wonderat his foundational achievement, but to help them to appreciate how even the most imaginative and rigorous science — and Mendel’s was first rateon both counts — bears the stamp of the historical circumstances of its making. To learn that lesson about past science is to bring a welcome level of self-awareness and critical self-reflection to the present.

### Gregory Radick is professor of history and philosophy of science at
the University of Leeds, UK, and president of the British Society for the
History of Science. This is an edited version of his presidential address,
to be published in the British Journal for the History of Science.
e-mail: g.m.radick@leeds.ac.uk

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