Spore Fleet

The Spore Fleet was a group of colony ships and generation ships from Alsakan and Corellia that spent several millennia between 15000 and 8000 BBY traveling to dozens of Human colonies across then galaxy and spreading various nonsentient lifeforms in order to assist Human populations in their societal development. The species spread by Spore ships included thousands of species of mammals, reptiles, avians, amphibians, crustaceans, fish, insects, arachnids, plants, fungi, and, unintentionally, bacteria. Over the course of millennia, some of these animals evolved according to their environment while others maintained their baseline characteristics. A majority of the creatures transported by the Spore Fleet originated from Alsakan, Corellia, Coruscant, Duro, and Talus, among other Core planets. By the time of the Imperial era (19 BBY-4 ABY), scientists estimated that more than ninety percent of the galaxy's lifeforms had interstellar origin, either as a result of the Spore Fleet, transportation by interstellar colonists, and in more ancient times, the Rakatan slave trade.

Around 8000 BBY, the Spore Fleet was destroyed after encountering a hyperspace anomaly that ended up disintegrating many small ships and causing the larger ones to end up in an asteroid field, where the remaining Spore ships were shredded by the space rocks.