The widely accepted MacArthur & Wilson model of island biogeography proposes a number of species that, after an initial growth, stabilize on each oceanic island at an equilibrium point. This species number depends on the available space, the vicinity of mainland, and the habitat diversification, thus being directly correlated with space characteristics. This space based model, however, does not explains some astonishingly evidences of species richness. The story length (the age) of each environment, possibly associated to the stability of conditions, should offer a better interpretation of species richness in each situation. Lakes, as water islands, more than land islands, have been considered in the present review as evidences of such an affection of the time on the species richness. The high species richness in the most ancient lakes is probably completely due to the genetic drift which produces diversification within each population possibly without any dependence from variability of conditions and habitats.
SPECIES RICHNESS IN ISOLATED ENVIRONMENTS: A CONSIDERATION ON THE EFFECT OF TIME
BELMONTE, Genuario
2012-01-01
Abstract
The widely accepted MacArthur & Wilson model of island biogeography proposes a number of species that, after an initial growth, stabilize on each oceanic island at an equilibrium point. This species number depends on the available space, the vicinity of mainland, and the habitat diversification, thus being directly correlated with space characteristics. This space based model, however, does not explains some astonishingly evidences of species richness. The story length (the age) of each environment, possibly associated to the stability of conditions, should offer a better interpretation of species richness in each situation. Lakes, as water islands, more than land islands, have been considered in the present review as evidences of such an affection of the time on the species richness. The high species richness in the most ancient lakes is probably completely due to the genetic drift which produces diversification within each population possibly without any dependence from variability of conditions and habitats.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
