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Making North America
''Making North America'' is a 2015 American documentary film which premiered nationwide on November 4, 2015. The PBS Nova film, comprising three episodes of one hour each, was hosted by Kirk Johnson (Director of the Smithsonian National Museum of Natural History); Peter Oxley directed the first episode while Gwyn Williams directed the second and third. The series describes the very beginnings and later developments of the North American continent: from the origin of planet Earth 4.54 billion years ago; to the various movements of tectonic plates and their effect on the sculpturing of the continent's land and mountains, including the Rocky Mountains, Yellowstone and the Grand Canyon; to the emergence of life on the continent and its later evolution; and, finally, to the more recent settlement of the land by humans. According to Johnson, "Most people will not have considered a time when there was no North America ... What was there before North America? How did it form? When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirk Johnson (scientist)
Kirk R. Johnson (born 1960) is an American paleontologist, author, curator, and museum administrator, and is currently serving as Sant Director of Smithsonian National Museum of Natural History. Early life and education Johnson was born in 1960 and grew up in Seattle, Washington. He attended Amherst College as an undergraduate, where he received a bachelor's degree in geology and fine arts. He joined Chi Psi fraternity. He then attended the University of Pennsylvania, earning a master's degree in geology and paleobotany. He received his Ph.D. in geology and paleobotany from Yale University in 1989. While in graduate school, in 1987, Johnson discovered an extinct species of linden leaf, which was named Tilia johnsoni in his honor. His postdoctoral work included field research in the northern Australian rainforests, while he served as a postdoctoral research associate in the department of botany at the University of Adelaide. Career From 1991 to 2012, Johnson worked at the Denver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinized name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phanerozoic
The Phanerozoic is the current and the latest of the four eon (geology), geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has population growth, proliferated, evolutionary radiation, diversified and colonization (biology), colonized various ecological niche, niches on the Earth's surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the ''Precambrian'', is now divided into the Hadean, Archean, Archaean and Proterozoic eons. The time span of the Phanerozoic starts with the Cambrian Explosion, sudden appearance of fossilised evidence of a number of animal phylum (biology), phyla; the evolution of those phyla into diverse forms; the evolutionary history of plants, evolution of plants; the evolution of fish, arthropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in life on Earth; prior to the Period, the majority of living organisms were small, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it was not until the Cambrian that fossil diversity seems to rapidly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life
Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, metabolism, Cell growth, growth, adaptation, response to stimulus (physiology), stimuli, and reproduction. All life over time eventually reaches a state of death, and none is Immortality, immortal. Many philosophical definitions of living systems have been proposed, such as self-organizing systems. Viruses in particular make definition difficult as they replicate only in Host (biology), host cells. Life exists all over the Earth in air, water, and soil, with many ecosystems forming the biosphere. Some of these are harsh environments occupied only by extremophiles. Life has been studied since ancient times, with theories such as Empedocles's materialism asserting that it was composed of Classical element, four eternal elements, and Aristotle's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of The Evolutionary History Of Life
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. In biology, evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organization, from kingdoms to species, and individual organisms and molecules, such as DNA and proteins. The similarities between all present day organisms imply a common ancestor from which all known species, living and extinct, have diverged. More than 99 percent of all species that ever lived (over five billion) are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, with about 1.2 million or 14% documented, the rest not yet described. However, a 2016 report estim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Oceans
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian, Antarctic/Southern, and Arctic Ocean),"Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, https://www.merriam-webster.com/dictionary/ocean . Accessed March 14, 2021. and are themselves mostly divided into s, s and subsequent bodies of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular Organism
A multicellular organism is an organism that consists of more than one cell (biology), cell, unlike unicellular organisms. All species of animals, Embryophyte, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social Amoeba, amoebae such as the genus ''Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony (biology), colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also macroscopic organisms that are multinucleate though technically unicellular, such as the Xenophyophorea that can reach 20 cm. Evolutionary history ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicellular Organism
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms. Most prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi. Unicellular organisms are thought to be the oldest form of life, with early organisms emerging 3.5–3.8 billion years ago. Although some prokaryotes live in colonies, they are not specialised cells with differing functions. These organisms live together, and each cell must carry out all life processes to survive. In contrast, even the simplest multicellular organisms have cells that depend on each other to survive. Most multicellular organisms have a unicellular life-cycle stage. Gametes, for example, are reprodu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phil
Phil may refer to: * Phil (given name), a shortened version of masculine and feminine names * Phill, a given name also spelled "Phil" * Phil, Kentucky, United States * Phil (film), ''Phil'' (film), a 2019 film * -phil-, a lexical fragment, used as a root term for many words * Philippines, a country in Southeast Asia, frequently abbreviated as ''PHIL'' * Philosophy, abbreviated as "phil." * Philology, abbreviated as "phil." * University Philosophical Society of Trinity College Dublin, Trinity College, Dublin, nicknamed "the Phil" See also * Master of Philosophy (M.Phil) * Doctor of Philosophy (D.Phil or Ph.D) * University Philosophical Society, known as "The Phil" * * Big Phil (other) * Dr. Phil (other) * Fil (other) * Fill (other) * Philip (other) * Philipp * Philippa * Philippic * Philipps {{dab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earliest Known Life Forms
The earliest known life forms on Earth may be as old as 4.1 billion years (or Year#SI prefix multipliers, Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a Stratigraphic unit, stratigraphic unit, not just a single mineral grain, is the 3.7 Ga Metasedimentary rock, metasedimentary rocks containing graphite from the Isua Greenstone Belt, Isua Supracrustal Belt in Greenland. The earliest direct known life on Earth are stromatolite fossils which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation, Dresser Formation of the Pilbara craton, Pilbara Craton of Western Australia. Various Micropaleontology#Microfossils, microfossils of Microorganism, microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Pilbara craton, Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
