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Map of early human migrations based on the Out of Africa theory; figures are in thousands of years ago (kya). [1]The peopling of the Americas began when Paleolithic hunter-gatherers (Paleo-Indians) entered North America from the North Asian Mammoth steppe via the Beringia land bridge, which had formed between northeastern Siberia and western Alaska due to the lowering of sea level during the ...
Schematic illustration of maternal (mtDNA) gene-flow in and out of Beringia, from 25,000 years ago to present. The genetic history of the Indigenous peoples of the Americas is divided into two distinct periods: the initial peopling of the Americas from about 20,000 to 14,000 years ago (20–14 kya), and European contact, after about 500 years ago.
A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves.These are separate from species that mainly live in above-ground habitats but are also able to live underground (eutroglophiles), and species that are only cave visitors (subtroglophiles and trogloxenes). [1]
This allowed land animals, followed by humans, to migrate south into the interior of the continent. The people went on foot or used boats along the coastline. The dates and routes of the peopling of the Americas remain subjects of ongoing debate. [3] It is likely there were three waves of ancient settlers from the Bering Sea to the America ...
They were one of several succeeding cultures often referred to as mound builders. The Oshara tradition people lived from 5500 BCE to 600 CE. They were part of the Southwestern Archaic tradition centered in north-central New Mexico, the San Juan Basin, the Rio Grande Valley, southern Colorado, and southeastern Utah.
The American Nation: A History of the United States: AP Edition (2008) Egerton, Douglas R. et al. The Atlantic World: A History, 1400–1888 (2007), college textbook; 530pp; Elliott, John H. Empires of the Atlantic World: Britain and Spain in America 1492–1830 (2007), 608pp excerpt and text search, advanced synthesis
Other trogloxenic animals include vertebrates such as bears, hyenas, other predators, reptiles, oilbirds, cave swiftlets and even humans, that enter for short term shelter or for hibernation. Most of them contribute organic matter rather than consuming it, and are important resources for troglobitic insects, many of which actually specialise in ...
Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies or appendages.