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Rapa Nui Palm
''Paschalococos disperta'', the Rapa Nui palm or Easter Island palm, formerly ''Jubaea disperta,'' was the native coccoid palm species of Easter Island. It disappeared from the pollen record circa AD 1650. Taxonomy It is not known whether the species is distinct from ''Jubaea,'' but there is no evidence that it was ''Jubaea'' either, as the soft tissues used for the identification of cocoid genera have not been preserved. All that remain are pollen from lake beds, hollow endocarps (nuts) found in a cave, and casts of root bosses. Partly to avoid giving credence to the common but speculative assumption that the palms were ''Jubaea chilensis'' and used as rollers to move the moai statues of Easter Island, John Dransfield assigned the species to a new genus. The assignment is not accepted by the World Checklist of Selected Plant Families, which does not list the genus ''Paschalococos'', nor by The Plant List which regards the name as "unresolved". Usage and extinction The over-har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently defined as the time between 129,000 and c. 11,700 years ago. The late Pleistocene equates to the proposed Tarantian Age of the geologic time scale, preceded by the officially ratified Chibanian (commonly known as the Middle Pleistocene). The beginning of the Late Pleistocene is the transition between the end of the Penultimate Glacial Period and the beginning of the Last Interglacial around 130,000 years ago (corresponding with the beginning of Marine Isotope Stage 5). The Late Pleistocene ends with the termination of the Younger Dryas, some 10th millennium BC, 11,700 years ago when the Holocene Epoch began. The term Upper Pleistocene is currently in use as a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collapse Of Society
Societal collapse (also known as civilizational collapse or systems collapse) is the fall of a complex human society characterized by the loss of cultural identity and of social complexity as an Complex adaptive system, adaptive system, the downfall of government, and the rise of violence. Possible causes of a societal collapse include natural catastrophe, war, pandemic, pestilence, famine, economic collapse, population decline or overshoot (population), overshoot, mass migration, Competence (human resources), incompetent leaders, and sabotage by rival civilizations. A collapsed society may revert to a more primitive state, be absorbed into a stronger society, or completely disappear. Virtually all civilizations have suffered such a fate, regardless of their size or complexity. Most never recovered, such as the Western and Eastern Roman Empires, the Spanish conquest of the Maya, Maya civilization, and the History of Easter Island#Destruction of society and population, Easter Isl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Extinctions Since 1500
Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular, except for some green algae. Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts, mosses, lycophytes, ferns, conifers and other gymnosperm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Arecaceae Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene Extinctions
The Holocene () is the current geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene is an interglacial period within the ongoing glacial cycles of the Quaternary, and is equivalent to Marine Isotope Stage 1. The Holocene correlates with the last maximum axial tilt towards the Sun of the Earth's obliquity. The Holocene corresponds with the rapid proliferation, growth, and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global significance for the future evolution of living species, including approximately synchronous lithospheric evidence, or more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Made Extinct By Human Activities
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour, or ecological niche. In addition, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomen". The first part of a binomen is the name of a genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes in zoological nomenclature). For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct Plants
Extinction is the termination of an organism by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. As a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, and mammoths. Through evolution, species arise through the process of speciation. Species become extinct when they are no longer able to survive in changing conditions or against superio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Easter Island
Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring ( indigenous) native plants. The corresponding term for animals is ''fauna'', and for fungi, it is '' funga''. Sometimes bacteria and fungi are also referred to as flora as in the terms ''gut flora'' or ''skin flora'' for purposes of specificity. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocoseae
Cocoseae is a tribe (biology), tribe of cocosoid palms of the family Arecaceae. Description The fruit of the Cocoseae is a modified drupe, with a sclerenchymatous epicarp and a highly developed mesocarp, formed mainly by parenchyma . The endocarp is generally sclerenchymatous and protects the seeds from predation and drying. The most obvious synapomorphy of the species of this tribe is the presence, in the endocarp, of three or more "eyes" or pores of germination. According to Thomas C. Whitmore all Cocosoid palms have inflorescences in which the flowers are in triads (sets of three flowers). Distribution The Cocoseae are distributed mainly in the Neotropical regions, with two genera endemic to Africa (''Jubaeopsis'' and ''Elaeis'') and Madagascar (''Beccariophoenix'' and ''Voanioala''), respectively. Systematics The Cocoseae in the sense of Dransfield et al. (2008) are identified as natural relatives (monophylum) in most studies. Their systematic position within the Arecoideae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rongorongo 067
Rongorongo ( or ; Rapa Nui: ) is a system of glyphs discovered in the 19th century on Easter Island that has the appearance of writing or proto-writing. Numerous attempts at decipherment have been made, but none have been successful. Although some calendrical and what might prove to be genealogical information has been identified, none of the glyphs can actually be read. If rongorongo does prove to be writing and to be an independent invention, it would be one of very few inventions of writing in human history. Two dozen wooden objects bearing rongorongo inscriptions, some heavily weathered, burned, or otherwise damaged, were collected in the late 19th century and are now scattered in museums and private collections. None remain on Easter Island. The objects are mostly tablets shaped from irregular pieces of wood, sometimes driftwood, but include a chieftain's staff, a ''tangata manu'' statuette, and two ''reimiro'' ornaments. There are also a few petroglyphs which may include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polynesian Rat
The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), or , is the third most widespread species of rat in the world behind the brown rat and black rat. Contrary to its vernacular name, the Polynesian rat originated in Southeast Asia, and like its relatives has become widespread, migrating to most of Polynesia, including New Zealand, Easter Island, and Hawaii. It shares high adaptability with other rat species extending to many environments, from grasslands to forests. It is also closely associated with humans, who provide easy access to food. It has become a major pest in most areas of its distribution. Description The Polynesian rat is similar in appearance to other rats, such as the black rat and the brown rat. It has large, round ears, a pointed snout, black/brown hair with a lighter belly, and comparatively small feet. It has a thin, long body, reaching up to in length from the nose to the base of the tail, making it slightly smaller than other human-associ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
