|
Chronospecies
A chronospecies is a species derived from a anagenesis, sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is physically, Comparative anatomy, morphologically, and/or Genetics, genetically distinct from the original ancestors. Throughout the change, there is only one species in the lineage at any point in time, as opposed to cases where divergent evolution produces contemporary species with a common ancestor. The related term paleospecies (or palaeospecies) indicates an extinct species only identified with fossil material. That identification relies on distinct similarities between the earlier fossil specimens and some proposed descendant although the exact relationship to the later species is not always defined. In particular, the range of variation within all the early fossil specimens does not exceed the observed range that exists in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. 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. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists 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. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronospecies
A chronospecies is a species derived from a anagenesis, sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is physically, Comparative anatomy, morphologically, and/or Genetics, genetically distinct from the original ancestors. Throughout the change, there is only one species in the lineage at any point in time, as opposed to cases where divergent evolution produces contemporary species with a common ancestor. The related term paleospecies (or palaeospecies) indicates an extinct species only identified with fossil material. That identification relies on distinct similarities between the earlier fossil specimens and some proposed descendant although the exact relationship to the later species is not always defined. In particular, the range of variation within all the early fossil specimens does not exceed the observed range that exists in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Divergent Evolution
Divergent evolution or divergent selection is the accumulation of differences between closely related populations within a species, leading to speciation. Divergent evolution is typically exhibited when two populations become separated by a geographic barrier (such as in allopatric or peripatric speciation) and experience different selective pressures that drive adaptations to their new environment. After many generations and continual evolution, the populations become less able to interbreed with one another. The American naturalist J. T. Gulick (1832–1923) was the first to use the term "divergent evolution", with its use becoming widespread in modern evolutionary literature. Classic examples of divergence in nature are the adaptive radiation of the finches of the Galapagos or the coloration differences in populations of a species that live in different habitats such as with pocket mice and fence lizards. The term can also be applied in molecular evolution, such as to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphic
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geologic map o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life forms on Earth. Evolution is based on the theory that all species are related and they gradually change over time. In a population, the genetic variations affect the physical characteristics i.e. phenotypes of an organism. These changes in the phenotypes will be an advantage to some organisms, which will then be passed onto their offspring. Some examples of evolution in species over many generations are the Peppered Moth and Flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. The importance of studying Evolutionary biology is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthogenesis
Orthogenesis, also known as orthogenetic evolution, progressive evolution, evolutionary progress, or progressionism, is an obsolete biological hypothesis that organisms have an innate tendency to evolve in a definite direction towards some goal (teleology) due to some internal mechanism or "driving force". According to the theory, the largest-scale trends in evolution have an absolute goal such as increasing biological complexity. Prominent historical figures who have championed some form of evolutionary progress include Jean-Baptiste Lamarck, Pierre Teilhard de Chardin, and Henri Bergson. The term ''orthogenesis'' was introduced by Wilhelm Haacke in 1893 and popularized by Theodor Eimer five years later. Proponents of orthogenesis had rejected the theory of natural selection as the organizing mechanism in evolution for a rectilinear model of directed evolution. With the emergence of the modern synthesis, in which genetics was integrated with evolution, orthogenesis and othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priabonian
The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene. Stratigraphic definition The Priabonian Stage was introduced in scientific literature by Ernest Munier-Chalmas and Albert de Lapparent in 1893. The stage is named after the small hamlet of Priabona in the community of Monte di Malo, in the Veneto region of northern Italy. The base of the Priabonian Stage is at the first appearance of calcareous nannoplankton species ''Chiasmolithus oamaruensis'' (which forms the base of nanoplankton biozone NP18). An official GSSP was ratified in 2020, and was placed in the Alano di Piave section in Alano di Piave, Belluno, Italy. The top of the Priabonian Stage (the base of the Rupelian Stage and Oligocene Series) is at the extinction of foram genus ''Hantkenina''. Sometimes local rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdiviathyris
''Valdiviathyris'' is a genus of craniate brachiopods that has changed little since the Silurian, from when fossils are known. The extant species ''V. quenstedti'' is known from the late Eocene. It was initially known only from the holotype collected from the southern Indian Ocean, near Île Saint-Paul, at a depth of . The specimen is considered to be adolescent and has a thin (0.1 mm thick) calcareous dorsal valve. This has an irregular conical shape, with the tip (or apex) not coinciding with the middle, and is on the outside only adorned by growth lines. On the inside it has pits (or punctae) that branch into four or five canals further to the outside. More recent specimens have been found near New Zealand. As long as no fossils of ''Vadiviathyris'' are found dating between the Silurian and the Eocene, this genus can be regarded a Lazarus taxon In paleontology, a Lazarus taxon (plural ''taxa'') is a taxon that disappears for one or more periods from the fossil record ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panthera
''Panthera'' is a genus within the family (biology), family Felidae that was named and described by Lorenz Oken in 1816 who placed all the spotted cats in this group. Reginald Innes Pocock revised the classification of this genus in 1916 as comprising the tiger (''P. tigris''), lion (''P. leo''), jaguar (''P. onca''), and leopard (''P. pardus'') on the basis of common Cranial bones, cranial features. Results of genetic analysis indicate that the snow leopard (formerly ''Uncia uncia'') also belongs to the genus ''Panthera'' (''P. uncia''), a classification that was accepted by IUCN Red List assessors in 2008. The tiger, lion, jaguar and leopard are the only cat species with anatomical structures that enable them to Roar (utterance), roar; the snow leopard cannot. The primary reason for this was formerly assumed to be the incomplete ossification of the hyoid bone. However, new studies show the ability to roar is due to other Morphology (biology), morphological features, especiall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnogyps
''Gymnogyps'' is a genus of New World vultures in the family Cathartidae. There are five known species in the genus, with only one being extant, the California condor. Fossil species *''Gymnogyps amplus'' was first described by L. H. Miller in 1911 from a broken tarsometatarsus. The species is the only condor species found in the La Brea Tar Pits' Pit 10, which fossils date to "a Holocene radiocarbon age of 9,000 years." The smaller, modern California condor may have evolved from ''G. amplus''. *''Gymnogyps howardae'' was described from the Late Pleistocene (Lujanian) asphalt deposits known as the Talara Tar Seeps, near Talara, northwestern Peru. It lived about 126,000-12,000 years ago. *''Gymnogyps kofordi'' was described based on a right tarsometatarsus. *'' Gymnogyps varonai'' is known from fossils found in the late Pleistocene to early Holocene tar seep deposits in Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Vulture
The black vulture (''Coragyps atratus''), also known as the American black vulture, Mexican vulture, zopilote, urubu, or gallinazo, is a bird in the New World vulture family whose range extends from the northeastern United States to Peru, Central Chile and Uruguay in South America. Although a common and widespread species, it has a somewhat more restricted distribution than its compatriot, the turkey vulture, which breeds well into Canada and south to Tierra del Fuego. It is the only extant member of the genus ''Coragyps'', which is in the family Cathartidae. Despite the similar name and appearance, this species is unrelated to the Eurasian black vulture, an Old World vulture in the family Accipitridae (which includes eagles, hawks, kites, and harriers). It inhabits relatively open areas which provide scattered forests or shrublands. With a wingspan of , the black vulture is a large bird, though relatively small for a vulture. It has black plumage, a featherless, grayish-bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassocnus
''Thalassocnus'' is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—''T. antiquus'', ''T. natans'', ''T. littoralis'', ''T. carolomartini'', and ''T. yuacensis''—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Horcón formations of Chile. Thalassocninae has been placed in both the families Megatheriidae and Nothrotheriidae. ''Thalassocnus'' evolved several marine adaptations over the course of 4 million years, such as dense and heavy bones to counteract buoyancy, the internal nostrils migrating farther into the head to help with breathing while completely submerged, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_(cropped).jpg "Click for more on -> Panthera")
