196 PAUL J. MARKWICK
Fig. 15. Diversity plotted with respect to PET. The close correlation between PET and the diversity of all
groups in North America is not seen in other parts of the world.
change. It also suggests that the critical limit on
species numbers is survival (extinction rate).
Ultimately, an organism is limited by its ability
to survive, and that depends on its adaptive
success in procuring energy and its physiological
ability to exist in a particular environmental
space.
Conclusions
A new GIS-based dataset of Recent taxonomic
diversity has been used to investigate the link
between modern terrestrial biodiversity
patterns and environmental variables. The
results suggest the following.
