Table 2.

Selective advantages and disadvantages of larger body size based on a compilation by Hone & Benton (2005)

Benefits of larger body size

-Increased defence against predation

-Increase in predation success

-Greater range of acceptable foods

-Increased success in mating

-Increased success in intraspecific competition

-Increased success in interspecific competition

-Extended longevity

-Increased intelligence (with increased brain size)

-At very large size, the potential for thermal inertia

-Survival through lean times and resistance to climatic variation and extremes

Problems caused by larger body size

-Increased vulnerability to predation

-Increased development time (both pre- and postnatal)

-Increased demand for resources

-Increased extinction risk because of:

-Longer generation time gives a slower rate of evolution, reducing the ability to adapt

-Lower abundance (i.e. small genetic pool, also reduces ability to adapt)

-Lower fecundity through reduced number of offspring