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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] |
Human Evolution
''Homo sapiens'' is a distinct species of the hominid family of primates, which also includes all the great apes. Over their evolutionary history, humans gradually developed traits such as Human skeletal changes due to bipedalism, bipedalism, dexterity, and complex language, as well as interbreeding with other hominins (a tribe of the Homininae, African hominid subfamily), indicating that human evolution was not linear but weblike. The study of the origins of humans involves Interdisciplinary, several scientific disciplines, including Biological anthropology, physical and evolutionary anthropology, paleontology, and genetics; the field is also known by the terms anthropogeny, anthropogenesis, and anthropogony—with the latter two sometimes used to refer to the related subject of hominization. Primate evolution, Primates diverged from other mammals about (Myr, mya), in the Late Cretaceous period, with their earliest fossils appearing over 55 mya, during the Paleocene. Prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modern Synthesis (20th Century)
The modern synthesis was the early 20th-century synthesis of Charles Darwin's theory of evolution and Gregor Mendel's ideas on Mendelian inheritance, heredity into a joint mathematical framework. Julian Huxley coined the term in his 1942 book, ''Evolution: The Modern Synthesis''. The synthesis combined the ideas of natural selection, Mendelian inheritance, Mendelian genetics, and population genetics. It also related the broad-scale macroevolution seen by paleontology, palaeontologists to the small-scale microevolution of local population, populations. The synthesis was defined differently by its founders, with Ernst Mayr in 1959, G. Ledyard Stebbins in 1966, and Theodosius Dobzhansky in 1974 offering differing basic postulates, though they all include natural selection, working on heritable variation supplied by mutation. Other major figures in the synthesis included E. B. Ford, Bernhard Rensch, Ivan Schmalhausen, and George Gaylord Simpson. An early event in the modern synthesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with selective breeding, artificial selection, which is intentional, whereas natural selection is not. Genetic diversity, Variation of traits, both Genotype, genotypic and phenotypic, exists within all populations of organisms. However, some traits are more likely to facilitate survival and reproductive success. Thus, these traits are passed the next generation. These traits can also become more Allele frequency, common within a population if the environment that favours these traits remains fixed. If new traits become more favoured due to changes in a specific Ecological niche, niche, microevolution occurs. If new traits become more favoured due to changes in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Genetics
Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as Adaptation (biology), adaptation, speciation, and population stratification, population structure. Population genetics was a vital ingredient in the emergence of the Modern synthesis (20th century), modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics. Traditionally a highly mathematical discipline, modern population genetics encompasses theoretical, laboratory, and field work. Population genetic models are used both for statistical inference from DNA sequence data and for proof/disproof of concept. What sets population genetics apart from newer, more phenotypic approaches to modelling evolution, such as evolutionary game theory and evolu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Drift
Genetic drift, also known as random genetic drift, allelic drift or the Wright effect, is the change in the Allele frequency, frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It can also cause initially rare alleles to become much more frequent and even fixed. When few copies of an allele exist, the effect of genetic drift is more notable, and when many copies exist, the effect is less notable (due to the law of large numbers). In the middle of the 20th century, vigorous debates occurred over the relative importance of natural selection versus neutral processes, including genetic drift. Ronald Fisher, who explained natural selection using Mendelian inheritance, Mendelian genetics, held the view that genetic drift plays at most a minor role in evolution, and this remained the dominant view for several decades. In 1968, population geneticist Mot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternatives To Evolution By Natural Selection
Alternatives to Darwinian evolution have been proposed by scholars investigating biology to explain signs of evolution and the relatedness of different groups of living things. The alternatives in question do not deny that evolutionary changes over time are the origin of the diversity of life, nor that the organisms alive today share a common ancestor from the distant past (or ancestors, in some proposals); rather, they propose alternative mechanisms of evolutionary change over time, arguing against mutations acted on by natural selection as the most important driver of evolutionary change. This distinguishes them from certain other kinds of arguments that deny that large-scale evolution of any sort has taken place, as in some forms of creationism, which do not propose alternative mechanisms of evolutionary change but instead deny that evolutionary change has taken place at all. Not all forms of creationism deny that evolutionary change takes place; notably, proponents of theis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication ( translesion synthesis). Mutations may also result from substitution, insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics ( phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a Common descent, common ancestor is now generally accepted and considered a fundamental scientific concept. In a joint presentation with Alfred Russel Wallace, he introduced his scientific theory that this Phylogenetics, branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.. Darwin has been described as one of the most influential figures in human history and was honoured by Burials and memorials in Westminster Abbey, burial in Westminster Abbey. Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh Medical Schoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On The Origin Of Species
''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life'')The book's full original title was ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life''. In the 1872 sixth edition, "On" was omitted, so the full title is ''The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life.'' This edition is usually known as ''The Origin of Species.'' The 6th is Darwin's final edition; there were minor modifications in the text of certain subsequent issues. See Freeman, R. B. In Van Wyhe, John, ed. ''Darwin Online: On the Origin of Species'', 2002. is a work of scientific literature by Charles Darwin that is considered to be the foundation of evolutionary biology. It was published on 24 November 1859. Darwin's book introduced the scientific theory that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Russel Wallace
Alfred Russel Wallace (8 January 1823 – 7 November 1913) was an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 paper on the subject was published that year On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection, alongside extracts from Charles Darwin's earlier writings on the topic. It spurred Darwin to set aside the Natural Selection (manuscript), "big species book" he was drafting and to quickly write an Abstract (summary), abstract of it, which was published in 1859 as ''On the Origin of Species''. Wallace did extensive fieldwork, starting in the Amazon River basin. He then did fieldwork in the Malay Archipelago, where he identified the faunal divide now termed the Wallace Line, which separates the Indonesian archipelago into two distinct parts: a western portion in which the ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Universal Common Ancestor
The last universal common ancestor (LUCA) is the hypothesized common ancestral cell from which the three domains of life, the Bacteria, the Archaea, and the Eukarya originated. The cell had a lipid bilayer; it possessed the genetic code and ribosomes which translated from DNA or RNA to proteins. Although the timing of the LUCA is not able to be definitively constrained, most studies suggest that the LUCA existed by or prior to 3.5 billion years ago, and possibly as early as 4.3 billion years ago or earlier. The nature of this point or stage of divergence remains a topic of research. All earlier forms of life preceding this divergence and all extant organisms are generally thought to share common ancestry. On the basis of a formal statistical test, this theory of a universal common ancestry (UCA) is supported versus competing multiple-ancestry hypotheses. The first universal common ancestor (FUCA) is a hypothetical non-cellular ancestor to LUCA and other now-extinct s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution (journal)
''Evolution: International Journal of Organic Evolution'', is a monthly scientific journal In academic publishing, a scientific journal is a periodical publication designed to further the progress of science by disseminating new research findings to the scientific community. These journals serve as a platform for researchers, schola ... that publishes significant new results of empirical or theoretical investigations concerning facts, processes, mechanics, or concepts of evolutionary phenomena and events. ''Evolution'' is published by Oxford Academic (formerly by Wiley) for the Society for the Study of Evolution. Its current editor-in-chief is Jason Wolf of the University of Bath, United Kingdom. Former editors-in-chief The journal was founded soon after the Second World War. Its first editor was the systematic ornithologist Ernst Mayr. * Ruth Geyer Shaw, July 2013 – 2017 * Daphne Fairbairn, 2010 – June 2013 References External links * at Oxford AcademicForm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
