plants evolved, and 95% of modern seed plants evolved in the mid-Miocene. The Pliocene lasted from 5.333 million to 2.58 million years ago. The Pliocene featured dramatic climatic changes, which ultimately led to modern species and plants. The Mediterranean Sea dried up for hundreds of thousand years in the Messinian salinity crisis. Along with these major geological events, Africa saw the appearance of Australopithecus, the ancestor of Homo. The isthmus of Panama formed, and animals migrated between North and South America, wreaking havoc on the local ecology. Climatic changes brought savannas that are still continuing to spread across the world, Indian monsoons, deserts in East Asia, and the beginnings of the Sahara desert. The Earth's continents and seas moved into their present shapes. The world map has not changed much since, save for changes brought about by the glaciations of the Quaternary, such as the Great Lakes. Quaternary Period The Quaternary spans from 2.58 million years ago to present day, and is the shortest geological period in the Phanerozoic Eon. It features modern animals, and dramatic changes in the climate. It is divided into two epochs: the Pleistocene and the Holocene. The Pleistocene lasted from 2.58 million to 11,700 years ago. This epoch was marked by a series of glacial periods (ice ages) as a result of the cooling trend that started in the Mid-Eocene. There were numerous separate glaciation periods marked by the advance of ice caps as far south as 40 degrees N latitude in mountainous areas. Meanwhile, Africa experienced a trend of desiccation which resulted in the creation of the Sahara, Namib, and Kalahari deserts. Mammoths, giant ground sloths, dire wolves, sabre-toothed cats, and humans were common and widespread during the Pleistocene. As the Pleistocene drew to a close, a major extinction wiped out much of the world's megafauna, including non-Homo sapiens human species such as Homo neanderthalensis. All the continents were affected, but Africa was impacted to a lesser extent. That continent retained many large animals, such as elephants, rhinos, and hippos. The extent to which Homo Sapiens were involved in this extinction is debated. The Holocene began 11,700 years ago and lasts until the present day. All recorded history and "Human history" lies within the boundaries of the Holocene epoch. Human activity is blamed for an ongoing mass extinction that began roughly 10,000 years ago, though the species becoming extinct have only been recorded since