Ecosystem Carnival

Insular biogeography
13 NOVEMBER 2014 (VIEWED) WIKIPEDIA

(Wikipedia) -- ... The theory of insular biogeography proposes that the number of species found in an undisturbed insular environment.. is determined by immigration and extinction... [T]he isolated populations may follow different evolutionary routes, as shown by Darwin's observation of finches in the Galapagos Islands.

Immigration and emigration are affected by the distance of an island from a source of colonists... Islands that are more isolated are less likely to receive immigrants than islands that are less isolated.

.. In addition to having an effect on immigration rates, isolation can also affect extinction rates.. Populations on islands that are less isolated are less likely to go extinct because individuals from the source population and other islands can immigrate and "rescue" the population from extinction; this is known as the rescue effect.  Read More