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River Out Of Eden
''River Out of Eden: A Darwinian View of Life'' is a 1995 popular science book by Richard Dawkins. The book is about Darwinian evolution and summarizes the topics covered in his earlier books, ''The Selfish Gene'', ''The Extended Phenotype'' and ''The Blind Watchmaker''. It is part of the ''Science Masters'' series and is Dawkins's shortest book. It is illustrated by Lalla Ward, Dawkins's then-wife. The book's name is derived from Genesis 2:10 relating to the Garden of Eden. The King James Version reads "And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads." ''River Out of Eden'' has five chapters. The first chapter lays down the framework on which the rest of the book is built, that life is like a river of genes flowing through geological time where organisms are mere temporary bodies. The second chapter shows how human ancestry can be traced via many gene pathways to different ''most recent common ancestors'', with speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Dawkins
Richard Dawkins (born 26 March 1941) is a British evolutionary biology, evolutionary biologist, zoologist, science communicator and author. He is an Oxford fellow, emeritus fellow of New College, Oxford, and was Simonyi Professor for the Public Understanding of Science, Professor for Public Understanding of Science at the University of Oxford from 1995 to 2008, and is on the advisory board of the University of Austin. His book ''The Selfish Gene'' (1976) popularised the gene-centred view of evolution and coined the word ''meme''. Dawkins has won several academic and writing awards. A vocal Atheism, atheist, Dawkins is known for his criticism of creationism and intelligent design. He wrote ''The Blind Watchmaker'' (1986), in which he argues against the watchmaker analogy, an argument for the existence of a creator deity based upon the Evolution of biological complexity, complexity of living organisms. Instead, he describes evolutionary processes as analogous to a ''blind'' watc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Most Recent Common Ancestor
A most recent common ancestor (MRCA), also known as a last common ancestor (LCA), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assumed to have been a species. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms. The ancestry of a set of individuals can sometimes be determined by referring to an established pedigree, although this may refer only to patrilineal or matrilineal lines for sexually-reproducing organisms with two parents, four grandparents, etc. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such ''time to most recent common ancestor'' (''TMRCA'') estimates can be given based on DNA test results and established mutation rates as practiced in genetic genealogy, or by reference to a non- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copying
Copying is the duplication of information or an wiktionary:artifact, artifact based on an instance of that information or artifact, and not using the process that originally generated it. With Analog device, analog forms of information, copying is only possible to a limited degree of accuracy, which depends on the quality of the equipment used and the skill of the operator. There is some inevitable generation loss, deterioration and accumulation of "noise (signal processing), noise" (random small changes) from original to copy when copies are made. This deterioration accumulates with each generation. With digital data, digital forms of information, copying is perfect. Copy and paste is frequently used by a computer user when they select and copy an area of text or content. In art In visual art, copying the works of the masters is a standard way that students learn to paint and sculpt. Often, artists will use the term ''after'' to credit the original artist in the title of the copy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alleles
An allele is a variant of the sequence of nucleotides at a particular location, or locus, on a DNA molecule. Alleles can differ at a single position through single nucleotide polymorphisms (SNP), but they can also have insertions and deletions of up to several thousand base pairs. Most alleles observed result in little or no change in the function or amount of the gene product(s) they code or regulate for. However, sometimes different alleles can result in different observable phenotypic traits, such as different pigmentation. A notable example of this is Gregor Mendel's discovery that the white and purple flower colors in pea plants were the result of a single gene with two alleles. Nearly all multicellular organisms have two sets of chromosomes at some point in their biological life cycle; that is, they are diploid. For a given locus, if the two chromosomes contain the same allele, they, and the organism, are homozygous with respect to that allele. If the alleles are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene-centered View Of Evolution
The gene-centered view of evolution, gene's eye view, gene selection theory, or selfish gene theory holds that adaptive evolution occurs through the differential survival of competing genes, increasing the allele frequency of those alleles whose phenotypic trait effects successfully promote their own propagation. The proponents of this viewpoint argue that, since heritable information is passed from generation to generation almost exclusively by DNA, natural selection and evolution are best considered from the perspective of genes. Proponents of the gene-centered viewpoint argue that it permits understanding of diverse phenomena such as altruism and intragenomic conflict that are otherwise difficult to explain from an organism-centered viewpoint. Some proponents claim that the gene-centered view is the aspect of evolutionary theory that is the most empirically validated, has the greatest predictive power, and has the broadest applicability. The gene-centered view of evolut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamarckism
Lamarckism, also known as Lamarckian inheritance or neo-Lamarckism, is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. It is also called the inheritance of acquired characteristics or more recently soft inheritance. The idea is named after the French zoologist Jean-Baptiste Lamarck (1744–1829), who incorporated the classical era theory of soft inheritance into his theory of evolution as a supplement to his concept of orthogenesis, a drive towards Evolution of biological complexity, complexity. Introductory textbooks contrast Lamarckism with Charles Darwin's theory of evolution by natural selection. However, Darwin's book ''On the Origin of Species'' gave credence to the idea of heritable effects of use and disuse, as Lamarck had done, and his own concept of pangenesis similarly implied soft inheritance. Many researchers from the 1860s onwards attempted to find evidence ... [...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] |
DNA Replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all life, living organisms, acting as the most essential part of heredity, biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a nucleic acid double helix, double helix of two Complementary DNA, complementary DNA strand, strands. DNA is often called double helix. The double helix describes the appearance of a double-stranded DNA which is composed of two linear strands that run opposite to each other and twist together. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generation
A generation is all of the people born and living at about the same time, regarded collectively. It also is "the average period, generally considered to be about 20–30 years, during which children are born and grow up, become adults, and begin to have children." In kinship, ''generation'' is a structural term, designating the parent–child relationship. In biology, ''generation'' also means biogenesis, reproduction, and procreation. ''Generation'' is also a synonym for ''birth/age cohort'' in demographics, marketing, and social science, where it means "people within a delineated population who experience the same significant events within a given period of time." The term ''generation'' in this sense, also known as '' social generations'', is widely used in popular culture and is a basis of sociological analysis. Serious analysis of generations began in the nineteenth century, emerging from an increasing awareness of the possibility of permanent social change and the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-celled Organism
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms. Most prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi. Unicellular organisms are thought to be the oldest form of life, with early organisms emerging 3.5–3.8 billion years ago. Although some prokaryotes live in colonies, they are not specialised cells with differing functions. These organisms live together, and each cell must carry out all life processes to survive. In contrast, even the simplest multicellular organisms have cells that depend on each other to survive. Most multicellular organisms have a unicellular life-cycle stage. Gametes, for example, are reproductiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary System
A planetary system is a set of gravity, gravitationally bound non-stellar Astronomical object, bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. For example, the Sun together with the planetary system revolving around it, including Earth, form the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems. Planetary systems are, by convention, named for their host, or parent star, as is the case in our Solar Planetary System, named for its hosting, star, "Sol". Debris disk, Debris disks are known to be common while other objects are more difficult to observe. Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraterrestrial Life
Extraterrestrial life, or alien life (colloquially, aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been scientifically conclusively detected. Such life might range from simple forms such as prokaryotes to Extraterrestrial intelligence, intelligent beings, possibly bringing forth civilizations that might be Kardashev scale, far more, or far less, advanced than humans. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology. Speculation about the possibility of inhabited worlds beyond Earth dates back to antiquity. Early Christianity, Christian writers discussed the idea of a "plurality of worlds" as proposed by earlier thinkers such as Democritus; Augustine of Hippo, Augustine references Epicurus's idea of innumerable worlds "throughout the boundless immensity of space" in ''The City of God''. Pre-modern writers typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
