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.
Founder effect refers to the loss of genetic variation in a new population that is derived from only a few members of a large population. A link can be found below.   When one of the new population is drawn from a small sample of the parental population it will be strikingly different geneticaly.