From molecules to phenotypes? – The promise and limits of integrative biology

Abstract

Is integrative biology a good idea, or even possible? There has been much interest lately in the unification of biology and the integration of traditionally separate disciplines such as molecular and developmental biology on one hand, and ecology and evolutionary biology on the other. In this paper I ask if and under what circumstances such integration of efforts actually makes sense. I develop by example an analogy with Aristotle's famous four "causes" that one can investigate concerning any object or phenomenon: material (what something is made of), formal (what distinguishes that particular object from others), efficient (how was the object made) and final (why was the object made). The example is provided by ongoing research on different aspects of flowering time in the model system Arabidopsis, a small weed belonging to the mustard family. I show that understanding how flowering time is controlled is an epistemologically different sort of question from why and how it evolved, and that the two research agendas can be pursued largely independently of each other. Toward the end, I propose that the real goal of integrative biology is to understand the boundary layers between levels of biological analysis, something to which modern philosophy of science can contribute significantly.Ist integrative Biologie eine gute Idee, oder überhaupt möglich? In letzter Zeit existiert ein großes Interesse an einer Vernetzung der Biologie und der Integration von traditionell separaten Disziplinen, wie der Molekular-und Entwicklungsbiologie auf der einen Seite und der Ökologie und Evolutionsbiologie auf der anderen. In dieser Arbeit frage ich, ob und unter welchen Bedingungen solch eine Integration der Bemühungen tatsächlich Sinn macht. An einem Beispiel entwickle ich eine Analogie zu Aristoteles berühmten vier "Gründen", mit denen man jedes betreffende Objekt oder Phänomen untersuchen kann: Material (aus was ist etwas gemacht), formal (was unterscheidet das betreffende Objekt von anderen), effizient (wie wurde das Objekt gemacht) und final (warum wurde das Objekt gemacht). Das Beispiel wird durch die laufende Forschung an unterschiedlichen Aspekten der Blütezeit im Modellsystem Arabidopsis geliefert, einem kleinen Kraut, das zu den Kreuzblütlern gehört. Ich zeige, dass das Verständnis, wie die Blütezeit kontrolliert wird, eine epistemologisch andere Art von Frage ist, wie diejenige, warum und wie sie evolvierte, und dass die zwei Forschungsagendas weitgehend unabhängig voneinander verfolgt werden können. Zum Ende lege ich nahe, dass das wirkliche Ziel der integrativen Biologie ist, die Grenzschichten zwischen Bereichen biologischer Analyse zu verstehen, etwas wozu die moderne Wissenschaftsphilosophie einen signifikanten Beitrag leisten kann.

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