Andrew Knoll | |
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Born | West Reading, Pennsylvania | April 23, 1951
Occupation | Botanist |
Awards |
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Scientific career | |
Thesis | Studies in Archean and early Proterozoic paleontology (1977) |
Website | eps |
Andrew Herbert Knoll (born 1951) is the Fisher Research Professor of Natural History [1] and a Research Professor of Earth and Planetary Sciences [2] at Harvard University. [2] [3] Born in West Reading, Pennsylvania, in 1951, Andrew Knoll graduated from Lehigh University with a Bachelor of Arts in 1973 [2] [3] and received his Ph.D. from Harvard University in 1977 [3] for a dissertation titled "Studies in Archean and Early Proterozoic Paleontology." [2] Knoll taught at Oberlin College for five years before returning to Harvard as a professor in 1982. [2] At Harvard, he serves in the departments of Organismic and Evolutionary Biology and Earth and Planetary Sciences. [1] [2]
Andrew Knoll is best known for his contributions to Precambrian paleontology and biogeochemistry. He has discovered microfossil records of early life in Spitsbergen, East Greenland, Siberia, China, Namibia, western North America, and Australia, [1] and was among the first to apply principles of taphonomy and paleoecology to their interpretation. He has also elucidated early records of skeletonized animals in Namibia and remarkable fossils of the Ediacaran Doushantuo Formation, China, preserved in exceptional cellular detail by early diagenetic phosphate precipitation. Knoll and colleagues authored the first paper to demonstrate strong stratigraphic variation in the carbon isotopic composition of carbonates and organic matter preserved in Neoproterozoic (1000–539 million years ago) sedimentary rocks, and Knoll's group also demonstrated that mid-Proterozoic carbonates display little isotopic variation through time, in contrast to both older and younger successions.
Knoll has longstanding interests in biomineralization, paleobotany, plankton evolution, and mass extinction. [1] [2] Among other things, Knoll and his colleagues were the first to hypothesize that rapid build-up of carbon dioxide played a key role in end-Permian mass extinction, 252 million years ago. More generally, Knoll uses physiology as a conceptual bridge to integrate geochemical records of environmental change with paleontological records of biological history. He has also served as a member of the science team for NASA's MER rover mission to Mars. [4]
Honors include membership in the US National Academy of Sciences, [5] the American Academy of Arts and Sciences, [6] the American Philosophical Society, [7] the American Academy of Microbiology, and Foreign Membership in the Royal Society of London and the National Academy of Sciences, India, as well as the Paleontological Society Medal, the Wollaston Medal of the Geological Society (London), the Moore Medal of the Society for Sedimentary Geology, the Oparin Medal of the International Society for the Study of the Origin of Life, the Sven Berggren Prize of the Royal Physiographic Society, Sweden, and both the Walcott and Thompson medals of the US National Academy of Sciences. He received the Phi Beta Kappa Book Award for "Life on a Young Planet: The First Three Billion Years of Evolution on Earth". In 2018, Knoll received the International Prize for Biology, conferred in Tokyo in the presence of the Emperor and Empress of Japan. In 2022, he received the Crafoord Prize in Geosciences.
The Ediacaran period is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya, to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon where recognizable fossil evidence of life becomes common.
The timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. Dates in this article are consensus estimates based on scientific evidence, mainly fossils.
The Paleoproterozoic Era is the first of the three sub-divisions (eras) of the Proterozoic eon, and also the longest era of the Earth's geological history, spanning from 2,500 to 1,600 million years ago (2.5–1.6 Ga). It is further subdivided into four geologic periods, namely the Siderian, Rhyacian, Orosirian and Statherian.
Panarthropoda is a proposed animal clade containing the extant phyla Arthropoda, Tardigrada and Onychophora. Panarthropods also include extinct marine legged worms known as lobopodians ("Lobopodia"), a paraphyletic group where the last common ancestor and basal members (stem-group) of each extant panarthropod phylum are thought to have risen. However the term "Lobopodia" is sometimes expanded to include tardigrades and onychophorans as well.
Geobiology is a field of scientific research that explores the interactions between the physical Earth and the biosphere. It is a relatively young field, and its borders are fluid. There is considerable overlap with the fields of ecology, evolutionary biology, microbiology, paleontology, and particularly soil science and biogeochemistry. Geobiology applies the principles and methods of biology, geology, and soil science to the study of the ancient history of the co-evolution of life and Earth as well as the role of life in the modern world. Geobiologic studies tend to be focused on microorganisms, and on the role that life plays in altering the chemical and physical environment of the pedosphere, which exists at the intersection of the lithosphere, atmosphere, hydrosphere and/or cryosphere. It differs from biogeochemistry in that the focus is on processes and organisms over space and time rather than on global chemical cycles.
The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, was a time interval during the Early Earth's Paleoproterozoic Era when the Earth's atmosphere and the shallow ocean first experienced a rise in the concentration of oxygen. This began approximately 2.460–2.426 Ga (billion years) ago, during the Siderian period, and ended approximately 2.060 Ga, during the Rhyacian. Geological, isotopic, and chemical evidence suggests that biologically-produced molecular oxygen (dioxygen or O2) started to accumulate in Earth's atmosphere and changed it from a weakly reducing atmosphere practically devoid of oxygen into an oxidizing one containing abundant free oxygen, with oxygen levels being as high as 10% of their present atmospheric level by the end of the GOE.
Elso Sterrenberg Barghoorn was an American paleobotanist, called by his student Andrew Knoll, the present Fisher Professor of Natural History at Harvard, "the father of Pre-Cambrian palaeontology."
The history of life on Earth traces the processes by which living and fossil organisms evolved, from the earliest emergence of life to present day. Earth formed about 4.5 billion years ago and evidence suggests that life emerged prior to 3.7 Ga. Although there is some evidence of life as early as 4.1 to 4.28 Ga, it remains controversial due to the possible non-biological formation of the purported fossils.
Philip Conrad James Donoghue FRS is a British palaeontologist and Professor of Palaeobiology at the University of Bristol.
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James William Schopf is an American paleobiologist and professor of earth sciences at the University of California Los Angeles. He is also Director of the Center for the Study of Evolution and the Origin of Life, and a member of the Department of Earth and Space Sciences, the Institute of Geophysics and Planetary Physics, and the Molecular Biology Institute at UCLA. He is most well known for his study of Precambrian prokaryotic life in Australia's Apex chert. Schopf has published extensively in the peer reviewed literature about the origins of life on Earth. He is the first to discover Precambrian microfossils in stromatolitic sediments of Australia (1965), South Africa (1966), Russia (1977), India (1978), and China (1984). He served as NASA's principal investigator of lunar samples during 1969–1974.
Lindsay E. Zanno is an American vertebrate paleontologist and a leading expert on theropod dinosaurs and Cretaceous paleoecosystems. She is the Head of Paleontology at the North Carolina Museum of Natural Sciences and an Associate Research Professor in the Department of Biological Sciences at North Carolina State University.
Roberta L. Rudnick is an American earth scientist and professor of geology at the University of California, Santa Barbara. She was elected a member of the National Academy of Sciences in 2010 and was awarded the Dana Medal by the Mineralogical Society of America. Rudnick is a world expert in the continental crust and lithosphere.
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