The unifying concept that forms the basis of scientific investigation in a particular field is called a paradigm.

Here's why:

* Paradigm: A paradigm is a framework or set of assumptions, theories, and practices that define a scientific discipline. It provides a shared understanding of the fundamental nature of the field, the questions to be asked, and the methods to be used.

* Examples:

* In physics, the Newtonian paradigm dominated for centuries, providing the foundation for understanding motion, gravity, and other physical phenomena.

* In biology, Darwin's theory of evolution by natural selection is a paradigm that shapes research in genetics, ecology, and other areas.

* Shifting Paradigms: Science is constantly evolving, and new discoveries can lead to paradigm shifts. These shifts occur when a new theory or understanding fundamentally alters how scientists view a field.

Let me know if you'd like more examples or clarification!