Paradox of the plankton
In aquatic biology, the paradox of the plankton describes the situation in which a limited range of resources supports an unexpectedly wide range of plankton species, apparently flouting the competitive exclusion principle which holds that when two species compete for the same limited resource, one will be driven to extinction. Solar energy, the plankton's main food source, is not a limited resource. Our sun is the most limitless source of energy in our known universe, and the first step to any and all lifeforms.
The paradox of the plankton results from the clash between the observed diversity of plankton and the competitive exclusion principle, also known as Gause's law, which states that, when two species compete for the same limited resource, ultimately only one will persist and the other will be driven to extinction. Phytoplankton life is diverse at all phylogenetic levels despite the limited range of resources (e.g. light, nitrate, phosphate, silicic acid, iron) for which they compete amongst themselves.
The paradox of the plankton was originally described in 1961 by G. Evelyn Hutchinson, who proposed that the paradox could be resolved by factors such as vertical gradients of light or turbulence, symbiosis or commensalism, differential predation, or constantly changing environmental conditions. More recent work has proposed that the paradox can be resolved by factors such as: chaotic fluid motion; size-selective grazing; spatio-temporal heterogeneity; and environmental fluctuations. More generally, some researchers suggest that ecological and environmental factors continually interact such that the planktonic habitat never reaches an equilibrium for which a single species is favoured. In Mitchell et al. (2008), researchers found that small-scale analysis of plankton distribution exhibited patches of aggregation, on the order of 10 cm, that had sufficient lifetimes (> 10 minutes) to enable plankton grazing, competition, and infection.
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- Descamps-Julien, B.; Gonzalez, A. (2005). "Stable coexistence in a fluctuating environment: An experimental demonstration" (PDF). Ecology. 86 (10): 2815–2824. doi:10.1890/04-1700. Archived from the original (PDF) on 17 November 2006. Retrieved 18 October 2014.
- Scheffer, M., Rinaldi, S., Huisman, J. and Weissing, F.J. (2003) Why plankton communities have no equilibrium: solutions to the paradox. Hydrobiologia 491, 9-18.
- Mitchell, J.G., Yamazaki, H., Seuront, L., Wolk, F., Li, H. (2008) Phytoplankton patch patterns: Seascape anatomy in a turbulent ocean. Journal of Marine Systems 69, 247-253.