The Abaco Islands. The Abaco Islands consists of several islands and cays (very small islands) that are great for exploring and snorkeling. Andros Island is the Bahamas' largest island but it's also the least developed. Like other Out Islands, Andros Island is ideal for eco-travelers.
bottleneck (bÅt'l-nÄk') An abrupt and severe reduction in the number of individuals during the history of a species, resulting in the loss of diversity from the gene pool. The generations following the bottleneck are more genetically homogenous than would otherwise be expected. Bottlenecks often occur in consequence of a catastrophic event.
This article is a good article explaining how the founder effects affect genetic drift. An example of a bottleneck effect: Northern elephant seals have reduced genetic variation most likely due to being hunted. Hunting reduced their population size to as few as 20 individuals at the end if the 19th century.