Climate characteristics during Holocene Epoch were warm, humid, and rich ground vegetation. World sea levels rose approx. 35 meters (110 feet) in the earlier Holocene due to melting ice. Habitable land expanding northwards. Large areas in Southwestern United States, became deserts. The Holocene brought about little animal and plant evolution, but there have been notable shifts in distribution. Extinction of mammoths, mastodons, saber-toothed cats, and giant sloths occured during the early Holocene.