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The Silurian hypothesis is a thought experiment, [ 1 ] which assesses modern science's ability to detect evidence of a prior advanced civilization, perhaps several million years ago. The most probable clues for such a civilization could be carbon, radioactive elements or temperature variation. The name "Silurian" derives from the eponymous ...
The timeline of human evolution outlines the major events in the evolutionary lineage of the modern human species, Homo sapiens, throughout the history of life, beginning some 4 billion years ago down to recent evolution within H. sapiens during and since the Last Glacial Period. It includes brief explanations of the various taxonomic ranks in ...
Arsenic is the 53rd most abundant element in the Earth's crust, comprising about 1.5 parts per million (0.00015%). [ 43 ] Typical background concentrations of arsenic do not exceed 3 ng/m 3 in the atmosphere; 100 mg/kg in soil; 400 μg/kg in vegetation; 10 μg/L in freshwater and 1.5 μg/L in seawater. [ 44 ]
Alvarez hypothesis. The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and ...
Lucy Catalog no. AL 288-1 Common name Lucy Species Australopithecus afarensis Age 3.2 million years Place discovered Afar Depression, Ethiopia Date discovered November 24, 1974 ; 49 years ago (1974-11-24) Discovered by Donald Johanson Maurice Taieb Yves Coppens Tom Gray AL 288-1, commonly known as Lucy or Dinkʼinesh, is a collection of several hundred pieces of fossilized bone comprising 40 ...
The direct association of the drawings with dinosaur fossil tracks is unique and may shed more light on rock art importance, meaning and significance, according to Radosław Palonka, an associate ...
Arsenic poisoning. Arsenic poisoning (or arsenicosis) is a medical condition that occurs due to elevated levels of arsenic in the body. [ 4 ] If arsenic poisoning occurs over a brief period of time, symptoms may include vomiting, abdominal pain, encephalopathy, and watery diarrhea that contains blood. [ 1 ]
The history of paleontology traces the history of the effort to understand the history of life on Earth by studying the fossil record left behind by living organisms. Since it is concerned with understanding living organisms of the past, paleontology can be considered to be a field of biology, but its historical development has been closely tied to geology and the effort to understand the ...