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.
The term bottleneck is often used in conjunction with a manufacturing facility and refers to a point in the production process where product bunches up, then slows down or stops completely. For example, if two conveyor belts merge into one, the point where they merge is the bottleneck.