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Elephant Bird
Elephant birds are members of the extinct ratite family Aepyornithidae, made up of flightless birds that once lived on the island of Madagascar. They are thought to have become extinct around 1000-1200 CE, probably as a result of human activity. Elephant birds comprised the genera '' Mullerornis'', '' Vorombe'' and '' Aepyornis''. While they were in close geographical proximity to the ostrich, their closest living relatives are kiwi (found only in New Zealand), suggesting that ratites did not diversify by vicariance during the breakup of Gondwana but instead evolved from ancestors that dispersed more recently by flying. In September 2018, scientists determined that ''Vorombe titan'' reached weights of and stood tall, making it the world's largest and heaviest bird, slightly larger than the much older '' Dromornis stirtoni''. Other members of the family were also very large, exhibiting the phenomenon of island gigantism. Description Elephant birds have been extinct since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Clock
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins. The benchmarks for determining the mutation rate are often fossil or archaeological dates. The molecular clock was first tested in 1962 on the hemoglobin protein variants of various animals, and is commonly used in molecular evolution to estimate times of speciation or radiation. It is sometimes called a gene clock or an evolutionary clock. Early discovery and genetic equidistance The notion of the existence of a so-called "molecular clock" was first attributed to Émile Zuckerkandl and Linus Pauling who, in 1962, noticed that the number of amino acid differences in hemoglobin between different lineages changes roughly linearly with time, as estimated from fossil evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicariance
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eremopezus
''Eremopezus'' is a prehistoric bird genus, possibly a palaeognath. It is known only from the fossil remains of a single species, the huge and presumably flightless ''Eremopezus eocaenus''. This was found in Upper Eocene Jebel Qatrani Formation deposits around the Qasr el Sagha escarpment, north of the Birket Qarun lake near Faiyum in Egypt. The rocks its fossils occur in were deposited in the Priabonian, with the oldest dating back to about 36 million years ago (Ma) and the youngest not less than about 33 Ma.Rasmussen ''et al.'' (1987, 2001) It is not precisely known from which strata the first few remains of this bird were collected. They were formerly considered of Early Oligocene age—some 33-30 Ma—but this is now assumed incorrect, as only the upper and not the entire Jebel Qatrani Formation is of Oligocene age. It is also possible that they are from the slightly older Qasr el Sagha Formation, but as both this and the Oligocene parts of the Jebel Qatrani Forma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burckhardt (ornithologist)
Burckhardt, or (de) Bourcard in French, is a family of the Basel patriciate, descended from Christoph (Stoffel) Burckhardt (1490–1578), a merchant in cloth and silk originally from Münstertal, Black Forest, who received Basel citizenship in 1523, and became a member of the Grand Council of Basel-Stadt in 1553. The family was represented in the Grand Council continuously from 1553 until the 20th century. In the 17th century and early 18th century, the family was the most powerful family of the canton of Basel. Branches of the family were based in Nantes and in the Kingdom of Naples from the 18th century, where it was ennobled as ''de Bourcard''. The family's famous members include the traveller and orientalist Johann Ludwig Burckhardt, the influential art historian Jacob Burckhardt and the international President of the Red Cross, Carl Jacob Burckhardt. The surname is derived from the dithematic Germanic given name '' Burkhard'', from ''burg'' "protection" and ''hard'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid digital media, digital subscribers. It also is a producer of popular podcasts such as ''The Daily (podcast), The Daily''. Founded in 1851 by Henry Jarvis Raymond and George Jones (publisher), George Jones, it was initially published by Raymond, Jones & Company. The ''Times'' has won List of Pulitzer Prizes awarded to The New York Times, 132 Pulitzer Prizes, the most of any newspaper, and has long been regarded as a national "newspaper of record". For print it is ranked List of newspapers by circulation, 18th in the world by circulation and List of newspapers in the United States, 3rd in the U.S. The paper is owned by the New York Times Company, which is Public company, publicly traded. It has been governed by the Sulzberger family since 189 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EurekAlert!
The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the betterment of all humanity. It is the world's largest general scientific society, with over 120,000 members, and is the publisher of the well-known scientific journal ''Science''. History Creation The American Association for the Advancement of Science was created on September 20, 1848, at the Academy of Natural Sciences in Philadelphia, Pennsylvania. It was a reformation of the Association of American Geologists and Naturalists. The society chose William Charles Redfield as their first president because he had proposed the most comprehensive plans for the organization. According to the first constitution which was agreed to at the September 20 meeting, the goal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Open Science
''Royal Society Open Science'' is a peer-reviewed open access scientific journal published by the Royal Society since September 2014. Its launch was announced in February 2014. It covers all scientific fields and publishes all articles which are scientifically sound, leaving any judgement of impact to the reader. As of 2022, the editor-in-chiefDame Wendy Hall DBE FRS FREng FCGI is supported by a team of Subject Editors and Associate Editors. Commissioning and peer review for the chemistry section of the journal is managed by the Royal Society of Chemistry. The journal offers Registered Reports across all subject disciplines, and Replications as a formal article type in the Psychology and Cognitive Neuroscience Section (as of 2019), though the journal welcomes replications in other disciplines, too. In 2021, the journal launched a new 'Science, Society and Policy' section of the journal. Articles published in ''Royal Society Open Science'' are regularly covered in the mainstream ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Academy Of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at the forefront of scientific developments in Europe in the 17th and 18th centuries, and is one of the earliest Academies of Sciences. Currently headed by Patrick Flandrin (President of the Academy), it is one of the five Academies of the Institut de France. History The Academy of Sciences traces its origin to Colbert's plan to create a general academy. He chose a small group of scholars who met on 22 December 1666 in the King's library, near the present-day Bibliothèque Nationals, and thereafter held twice-weekly working meetings there in the two rooms assigned to the group. The first 30 years of the Academy's existence were relatively informal, since no statutes had as yet been laid down for the institution. In contrast to its Bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marco Polo
Marco Polo (, , ; 8 January 1324) was a Venetian merchant, explorer and writer who travelled through Asia along the Silk Road between 1271 and 1295. His travels are recorded in '' The Travels of Marco Polo'' (also known as ''Book of the Marvels of the World '' and ''Il Milione'', ), a book that described to Europeans the then mysterious culture and inner workings of the Eastern world, including the wealth and great size of the Mongol Empire and China in the Yuan Dynasty, giving their first comprehensive look into China, Persia, India, Japan and other Asian cities and countries. Born in Venice, Marco learned the mercantile trade from his father and his uncle, Niccolò and Maffeo, who travelled through Asia and met Kublai Khan. In 1269, they returned to Venice to meet Marco for the first time. The three of them embarked on an epic journey to Asia, exploring many places along the Silk Road until they reached Cathay (China). They were received by the royal court of Kublai Khan, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Étienne De Flacourt
Étienne de Flacourt (1607–1660) was a French governor of Madagascar, born in Orléans in 1607. He was named governor of Madagascar by the French East India Company in 1648. Flacourt restored order among the French soldiers, who had mutinied. In his dealings with the Malagasy, he was less successful; he was continually harassed by their intrigues and attacks during his entire term of office. In 1655 he returned to France and, not long after, he was appointed director general of the company; after again returning to Madagascar, he drowned on his voyage home on the 10th of June 1660. He is the author of a ''Histoire de la grande isle de Madagascar'' (1st edition 1658, 2nd edition 1661). Flacourt was one of the few, if not the only, Westerners to have recorded knowledge of the elephant birds of Madagascar when they were possibly still extant. '' Flacourtia'', a genus of flowering plants in the willow family, Salicaceae The Salicaceae is the willow family of flowering pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Island Gigantism
Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general Foster's rule, "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies (insular dwarfism). This is itself one aspect of the more general phenomenon of island syndrome which describes the differences in Morphology (biology), morphology, ecology, physiology and ethology, behaviour of insular species compared to their continental counterparts. Following the arrival of humans and associated introduced predators (dogs, cats, rats, pigs), many giant as well as other island endemics have become Extinction, extinct. A similar size increase, as well as increased woodiness, has been observed in some insular plants. Possible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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