Table 1.
Some theories of species diversity
| Theory | Author, date | Ref(s). |
| Nonmechanistic | ||
| Broken stick | MacArthur, 1957 | 1 |
| Log normal | Preston, 1962 | 2 |
| Log series | Whittaker, 1965 | 3 |
| Neutral theory | Hubbell, 1979, 2001 | 4, 5 |
| Heterogeneity | ||
| Intermediate disturbance | Connell, 1978 | 6 |
| Lottery competition | Chesson and Warner, 1981 | 7 |
| Spatial heterogeneity | Tilman and Pacala, 1993 | 8 |
| Dispersal limitation | Tilman, 1994 | 9 |
| Winner by forfeit | Hurtt and Pacala, 1995 | 10 |
| Individual variation | Clark, 2010 | 11 |
| Bottom-up | ||
| Resource competition | Lotka, 1925 | 12 |
| Resource competition | Volterra, 1926 | 13 |
| Limiting similarity | Hutchinson, 1959 | 14 |
| Habitat complexity | MacArthur and MacArthur, 1961 | 15 |
| Immigration vs. extinction | MacArthur and Wilson, 1967 | 16 |
| Resource gradients | Tilman, 1982 | 17 |
| Productivity | Brown, 2014 | 18 |
| Top-down | ||
| Keystone predation | Paine, 1966 | 19 |
| Escape in space | Janzen, 1970 | 20 |
| Escape in space | Connell, 1971 | 21 |
| Predation/competition | Menge and Sutherland, 1976 | 22 |
| Pathogens | Givnish, 1999 | 23 |
| Predation/competition | Chesson and Kuang, 2008 | 24 |