Variations in environmental conditions and fluctuations in other species all exert an effect. Sooner or later, all populations will run to extinction under natural circumstances. All of the concerns of conservation biology mentioned above have a hand in increasing the extinction rates of many species. Habitat destruction and fragmentation are possibly the biggest causes of extinction. As habitat is eroded, species reliant upon that habitat reduce in number.
Fragmentation isolates proportionally small populations, reducing genetic variability over time.
Metapopulations can be modelled with respect to networks of genetic exchange between core and satellite populations. Protected Habitats Arguably, the greatest priority for conservationists is the preservation of habitats. This should conserve biodiversity most efficiently. Thus a crucial step in protecting biological communities is the establishment of protected areas. GIS can be an important tool for establishing and managing nature reserves.