Collaboration has quickly become the de facto standard in the life sciences. There are examples in every discipline; to give you something specific would only highlight my ignorance of other fields. It happens between members of the same lab group, between groups and between institutions. The single-author publication is becoming a rarity.<p>For an example from my own experience, researcher A makes a groundbreaking discovery in a disease, and collaborates with mouse expert researcher B at a different institution to develop a model for this. For the most part, any paper in a respected journal with authors from various institutions reflects an aspect of this collaboration.