Description and significance. Anaplasma marginale is the most prevalent tick-borne, livestock pathogen worldwide and poses a considerable constraint to animal health. The disease results in significant morbidity and mortality of United State's (US) cattle population, which affects the exportation of beef.
The Geological period consists of time periods in the origin and evolution of earth. The earth is about 4.5 billion years old. The time from the origin of the earth to the present is divided into super eons, eons, eras and periods. The Precambrian period is a super eon that is sub-divided into three eons: â¢ the Hadean Eon (4.5 to 3.8 billion years before present), â¢ the Archean Eon (3.8 to 2.5 billion years before present),, and.
Reconstruction of the map of the world according to drift theory for three epochs, the upper one is the upper Carboniferous, the middle one is for the Eocene, and the lower one is for the Lower Quaternary. The dotted areas on the continents are areas where shallow seas existed during those time periods.