Studies of altitudinal gradients in species richness have increasingly replaced the latitudinal gradient as a model template for large-scale gradient studies 9. Altitudinal gradients encompass several ...

The type of graph is important to show the meaning of the data in an easy-to-understand manner, but the color coding is also an important factor. Color coding can indicate that the data is of the same ...

The geographic area hypothesis advances area as the primary cause of latitudinal gradients in diversity. The greater area of tropical zones, it suggests, stimulates speciation, inhibits extinction, ...