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.
Simple illustration of founder effect. The original population is on the left with three possible founder populations on the right. In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population.