Mardi Gras-a carnival held in some countries on Shrove Tuesday (the last day before Lent) but especially in New Orleans.
Bottleneck effect is when there's something that either kills the majority of the population or just prevents it from reproducing. This creates genetic drift because the likelihood of gene prominence changing is much higher in a small population. The Founder Effect is a type of Bottleneck effect. It is when a small amount of individuals starts a population usually due to migration.
Unlike bottlenecks, which persist as long as the effective population size remains low, a founder effect is an instant event. Here is a link to a website that delves into the genomic heritage of the people of Quebec. Quebec is a community whose genomic heritage is a result of founder effects.