8
Dynamic Zoogeography
Therefore, the Lessepsian migration may serve not only as an example of the
establishment of a new zoogeographie provinee, but also of the evolutionary
eonsequenee of this-the appearanee of vicariant (i. e. zoogeographieally replaeing) speeies whieh ean be monitored.
The Lessepsian migrants are near-ideal eases for what Mayr (1965a) calls "peripheral isolates". These isolates, eonneeted to their parental populations only
through the gene triekle via the narrow Suez Canal, are prone to undergo major
eeologie shifts leading to speeiation.