Figure 1
From: Detecting adaptive evolution based on association with ecological gradients: Orientation matters!
Schematic representation of evolutionary scenarios. Populations (demes) are represented by a regular array of dots, the larger ones indicating the origin of expansion. The main direction of expansion is shown by black arrow (solid line), the circular wave front is shown by an orange circle. The main axis of the ecological gradient is shown by a green arrow (dashed line) which angle varies from −90 degrees to +90 degrees.
