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Winter Wren
The winter wren (''Troglodytes hiemalis'') is a very small North American bird and a member of the mainly New World wren family Troglodytidae. It was once lumped with the Pacific wren (''Troglodytes pacificus'') of western North America and the Eurasian wren ''(Troglodytes troglodytes)'' of Eurasia under the name winter wren. It breeds in coniferous forests from British Columbia to the Atlantic Ocean. It migrates through and winters across southeastern Canada, the eastern half the United States and (rarely) north-eastern Mexico. Small numbers may be casual in the western United States and Canada. The scientific name is taken from the Greek word ''troglodytes'' (from "trogle" a hole, and "dyein" to creep), meaning "cave-dweller", and refers to its habit of disappearing into cavities or crevices while hunting arthropods or to roost. Taxonomy The winter wren was described and illustrated in 1808 by the American ornithologist Alexander Wilson. He was uncertain as to whether the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurasian Wren
The Eurasian wren (''Troglodytes troglodytes'') or northern wren is a very small insectivorous bird, and the only member of the wren family Troglodytidae found in Eurasia and Africa (Maghreb). In Anglophone Europe, it is commonly known simply as the wren. It has a very short tail which is often held erect, a short neck and a relative long thin bill. It is russet brown above, paler buff-brown below and has a cream buff supercilium. The sexes are alike. The species was once lumped with ''Troglodytes hiemalis'' of eastern North America and '' Troglodytes pacificus'' of western North America as the winter wren. The Eurasian wren occurs in Europe and across the Palearctic – including a belt of Asia from northern Iran and Afghanistan across to Japan. It is migratory in only the northern parts of its range. It is also highly polygynous, an unusual mating system for passerines. The scientific name is taken from the Greek word "troglodytes" (from τρώγλη "hole", and δῠ� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Wren
The Pacific wren (''Troglodytes pacificus'') is a very small North American bird and a member of the mainly New World wren family Troglodytidae. It was once lumped with ''Troglodytes hiemalis'' of eastern North America and ''Troglodytes troglodytes'' of Eurasia as the winter wren. It breeds along the Pacific coast from Alaska to California and inland as far as Wyoming and the Black Hills of South Dakota. It migrates through and winters across the western half of the United States and Canada. The scientific name is taken from the Greek word "troglodytes" (from "trogle" a hole, and "dyein" to creep), meaning "cave-dweller", and refers to its habit of disappearing into cavities or crevices whilst hunting arthropods or to roost. Description Rufous brown above, richly colored below, barred with darker brown and dusky, even on wings and tail. The bill is dark brown, the legs pale brown. Young birds are less distinctly barred. Taxonomy By studying the songs and genetics of individ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prospect Park (Brooklyn)
Prospect Park is an urban park in Brooklyn, New York City. The park is situated between the neighborhoods of Park Slope, Prospect Heights, Prospect Lefferts Gardens, Flatbush, and Windsor Terrace, and is adjacent to the Brooklyn Museum, Grand Army Plaza, and the Brooklyn Botanic Garden. With an area of , Prospect Park is the second largest public park in Brooklyn, behind Marine Park. First proposed in legislation passed in 1859, Prospect Park was laid out by Frederick Law Olmsted and Calvert Vaux, who also helped design Manhattan's Central Park, following various changes to its design. Prospect Park opened in 1867, though it was not substantially complete until 1873. The park subsequently underwent numerous modifications and expansions to its facilities. Several additions to the park were completed in the 1890s, in the City Beautiful architectural movement. In the early 20th century, New York City Department of Parks and Recreation (NYC Parks) commissioner Robert Mose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binomial Name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name (which may be shortened to just "binomial"), a binomen, name or a scientific name; more informally it is also historically called a Latin name. The first part of the name – the '' generic name'' – identifies the genus to which the species belongs, whereas the second part – the specific name or specific epithet – distinguishes the species within the genus. For example, modern humans belong to the genus ''Homo'' and within this genus to the species ''Homo sapiens''. ''Tyrannosaurus rex'' is likely the most widely known binomial. The ''formal'' introduction of this system of naming species is credit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book ''On the Origin of Species''. He also identified sexual selection as a likely mechanism, but found it problematic. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject of much ongoing discussion. Rapid sympatric speciation can take place through polyploidy, such as by doubling of chromosome numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing a faunal interchange between the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Ancestor
Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal common ancestor (LUCA) of all life on Earth, according to modern evolutionary biology. Common descent is an effect of speciation, in which multiple species derive from a single ancestral population. The more recent the ancestral population two species have in common, the more closely are they related. The most recent common ancestor of all currently living organisms is the last universal ancestor, which lived about 3.9 billion years ago. The two earliest pieces of evidence for life on Earth are graphite found to be biogenic in 3.7 billion-year-old metasedimentary rocks discovered in western Greenland and microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. All currently living organisms on Earth s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being deri ... [...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 ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Isolation
The mechanisms of reproductive isolation are a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile. These barriers maintain the integrity of a species by reducing gene flow between related species.Strickberger, M. 1978. ''Genética''. Omega, Barcelona, España, p.: 874-879. .Futuyma, D. 1998. ''Evolutionary biology'' (3ª edición). Sinauer, Sunderland. The mechanisms of reproductive isolation have been classified in a number of ways. Zoologist Ernst Mayr classified the mechanisms of reproductive isolation in two broad categories: pre-zygotic for those that act before fertilization (or before mating in the case of animals) and post-zygotic for those that act after it.Mayr, E. 1963. ''Animal species and evolution''. Harvard University Press, Cambridge. The mechanisms are genetically controlled and can appear in species who ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Trait inheritance and molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the cell, the organism (e.g. dominance), and within the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conspecific
Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organisms or constituents of living organisms of being special or doing something special. Each animal or plant species is special. It differs in some way from all other species...biological specificity is the major problem about understanding life." Biological specificity within ''Homo sapiens'' ''Homo sapiens'' has many characteristics that show the biological specificity in the form of behavior and morphological traits. Morphologically, humans have an enlarged cranial capacity and more gracile features in comparison to other hominins. The reduction of dentition is a feature that allows for the advantage of adaptability in diet and survival. As a species, humans are culture dependent and much of human survival relies on the culture and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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