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Gradual Evolution
Anagenesis is the gradual evolution of a species that continues to exist as an interbreeding population. This contrasts with cladogenesis, which occurs when branching or splitting occurs, leading to two or more lineages and resulting in separate species. Anagenesis does not always lead to the formation of a new species from an ancestral species. When speciation does occur as different lineages branch off and cease to interbreed, a core group may continue to be defined as the original species. The evolution of this group, without extinction or species selection, is anagenesis. Hypotheses One hypothesis is that during the speciation event in anagenetic evolution, the original populations increases quickly, and then racks up genetic variation over long periods of time by mutation and recombination in a stable environment. Other factors, such as selection or genetic drift will have such a significant effect on genetic material and physical traits that a species can be acknowledged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation. The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book ''On the Origin of Species''. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) phenotypic variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkeley, it is the state's first land-grant university and is the founding campus of the University of California system. Berkeley has an enrollment of more than 45,000 students. The university is organized around fifteen schools of study on the same campus, including the UC Berkeley College of Chemistry, College of Chemistry, the UC Berkeley College of Engineering, College of Engineering, UC Berkeley College of Letters and Science, College of Letters and Science, and the Haas School of Business. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Lawrence Berkeley National Laboratory was originally founded as par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marc Ereshefsky
Marc Ereshefsky is a professor of philosophy at the University of Calgary, specializing in the philosophy of science and the philosophy of biology. His research focuses on issues on the intersection of philosophy and biology. Ereshefsky is specifically known for his work on taxonomy, systematics and natural kinds. His research has been supported by the Social Sciences and Humanities Research Council of Canada, the Canadian Institutes of Health Research, and the National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su .... Personal life Ereshefsky lives in Calgary with his wife, two sons, Jacob and Josh, and their puppy. His favourite weekend activities include hiking in the nearby Rocky Mountains, and going for runs. Publications Books * ''The Units of Evolution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the science, scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxon, taxa (singular: taxon), and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain (biology), domain, kingdom (biology), kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class (biology), class, order (biology), order, family (biology), family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, having developed a ranked system known as Linnaean taxonomy for categorizing organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plio-Pleistocene
The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 Mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene"; see below. In the contexts of archaeology, paleontology, and paleoanthropology, the Plio-Pleistocene is a very useful period to which scientists may assign the long and continuous run in East Africa of datable sedimentary layers and their contents (e.g. the Bouri Formation). These contents collectively present a focused view of the continuous evolution of the region's large vertebrates, especially the evolution of some African apes ( hominids) to the earliest hominins; and then the development of the early humans and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene followed the Oligocene and preceded the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by distinct global events but by regionally defined transitions from the warmer Oligocene to the cooler Pliocene Epoch. During the Early Miocene, Afro-Arabia collided with Eurasia, severing the connection between the Mediterranean and Indian Oceans, and allowing the interchange of fauna between Eurasia and Africa, including the dispersal of proboscideans and Ape, hominoids into Eurasia. During the late Miocene, the conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58See the 2014 version of the ICS geologic time scale million years ago (Ma). It is the second and most recent epoch of the Neogene Period in the Cenozoic, Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.59 to 1.81 Ma, and is now included in the Pleistocene. As with other older geologic periods, the Stratum, geological strata that define the start and end are well-identified but the exact dates of the start a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hominin
The Hominini (hominins) form a taxonomic tribe of the subfamily Homininae (hominines). They comprise two extant genera: ''Homo'' (humans) and '' Pan'' (chimpanzees and bonobos), and in standard usage exclude the genus '' Gorilla'' ( gorillas), which is grouped separately within the subfamily Homininae. The term Hominini was originally introduced by Camille Arambourg (1948), who combined the categories of ''Hominina'' and ''Simiina'' pursuant to Gray's classifications (1825). Traditionally, chimpanzees, gorillas and orangutans were grouped together, excluding humans, as pongids. Since Gray's classifications, evidence accumulating from genetic phylogeny confirmed that humans, chimpanzees, and gorillas are more closely related to each other than to the orangutan. The orangutans were reassigned to the family Hominidae ( great apes), which already included humans; and the gorillas were grouped as a separate tribe (Gorillini) of the subfamily Homininae. Still, details of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoanthropologist
Paleoanthropology or paleo-anthropology is a branch of paleontology and biological anthropology, anthropology which seeks to understand the early development of anatomically modern humans, a process known as wikt:hominization, hominization, through the reconstruction of evolutionary kinship lines within the family Hominidae, working from biological evidence (such as petrified skeletal remains, fossil, bone fragments, footprints) and cultural evidence (such as stone tools, artifacts, and settlement localities). The field draws from and combines primatology, paleontology, biological anthropology, and cultural anthropology. As technologies and methods advance, genetics plays an ever-increasing role, in particular to examine and compare DNA structure as a vital tool of research of the evolutionary kinship lines of related species and genera. Etymology The term paleoanthropology derives from Greek palaiós (παλαιός) "old, ancient", ánthrōpos (ἄνθρωπος) "man, human" an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milford H
Milford may refer to: Place names Canada * Milford (Annapolis), Nova Scotia * Milford (Halifax), Nova Scotia * Milford, Ontario England * Milford, Derbyshire * Milford, Devon, a List of United Kingdom locations: Milb-Milk, place in Devon * Milford on Sea, Hampshire * Milford, Shropshire, a List of United Kingdom locations: Milb-Milk, place in Shropshire * Milford, Staffordshire * Milford, Surrey ** served by Milford railway station * Milford, Wiltshire Ireland * Milford, County Cork * Milford, County Donegal New Zealand * Milford Sound * Milford Track * Milford, New Zealand, a suburb of Auckland Northern Ireland * Milford, County Armagh Wales * Milford, Powys, a List of United Kingdom locations: Milb-Milk#Milb-Milk, location * Milford Haven, Pembrokeshire United States * Milford, California * Milford, Connecticut ** Milford station (Connecticut), commuter rail station * Milford, Delaware * Milford Hundred, an unincorporated subdivision of Kent County, Delaware ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Grade
A grade is a taxon united by a level of morphological or physiological complexity. The term was coined by British biologist Julian Huxley, to contrast with clade, a strictly phylogenetic unit. Phylogenetics The concept of evolutionary grades arises in the context of phylogenetics: the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. Definition of an evolutionary grade An evolutionary grade is a group of species united by morphological or physiological traits, that has given rise to another group that has major differences from the ancestral group's condition, and is thus not considered p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraspecies
A paraspecies (a paraphyletic species) is a species, living or fossil, that gave rise to one or more daughter species without itself becoming extinct. Geographically widespread species that have given rise to one or more daughter species as peripheral isolates without themselves becoming extinct (i.e. through peripatric speciation) are examples of paraspecies. Paraspecies are expected from evolutionary theory (Crisp and Chandler, 1996), and are empirical realities in many terrestrial and aquatic taxa. Examples * A well-documented example of a living mammal species that gave rise to another living species is the evolution of the polar bear from the brown bear. * An example of a living reptile paraspecies is New Zealand's North Island tuatara ''Sphenodon punctatus'', which gave rise to the Brothers Island tuatara '' Sphenodon guntheri''. An example of a living bird paraspecies is '' Empidonax occidentalis'', the Cordilleran flycatcher. * An example of a living plant paraspecies is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
