For each of the following scenarios label what type of genetic...

For each of the following scenarios label what type of genetic drift is occurring; bottleneck effect, founder effect, drift by chance.  (Provide support for your decision.)

1. A very small population of snails have either blue shells or purple shells.  The phenotypic ratio of the current generation of snails is 2:1, blue:purple. The environment in which the snails live and then breed in remains constant with no changes in the availability of resources or predation pressure. The next generation of snails are all blue.
2. A very small population of snails have either blue shells or purple shells.  The phenotypic ratio of the current generation of snails is 2:1, blue:purple. There is a flood and many snails die. The generation born after the flood is all blue.
3. A very small population of snails have either blue shells or purple shells.  The phenotypic ratio of the current generation of snails is 2:1, blue:purple. There is a flood that carries part of the population away on a log while the rest stay where they currently are. The population that floated away breeds just within their segmented population and the resulting generation is 1:1 blue to purple.