NationMaster - Encyclopedia: Microevolution

Microevolution is the occurrence of small-scale changes in allele frequencies in a population, over a few generations, also known as change at or below the species level. In biology, a species is the basic unit of biodiversity. ...

These changes may be due to several processes: mutation, natural selection, gene flow, and genetic drift. In biology, mutations are changes to the genetic material (usually DNA or RNA). ... Natural Selection is the phrase Charles Darwin used in 1859 in his book The Origin of Species to name the natural process he proposed to be responsible for the origin of new species and the adaptation of organisms to their environments. ... Gene flow (also known as gene migration) is the transfer of genes from one population to another. ... Genetic drift is the term used in population genetics to refer to the statistical drift over time of allele frequencies in a finite population due to random sampling effects in the formation of successive generations. ...

Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance. Population genetics is the study of the distribution of and change in allele frequencies under the influence of the four evolutionary forces: natural selection, genetic drift, mutation, and migration. ... Ecological genetics is the study of genetics (itself a field of biology) from an ecological perspective. ... â€¹ The template below has been proposed for deletion. ... Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic. ...

Microevolution can be contrasted with macroevolution; which is the occurrence of large-scale changes in gene frequencies, in a population, over a geological time period (i.e. consisting of lots of microevolution). The difference is largely one of approach. Microevolution is reductionist, but macroevolution is holistic. Each approach offers different insights into evolution. Macroevolution refers to evolution that occurs above the level of species. ... Reductionism in philosophy describes a number of related, contentious theories that hold, very roughly, that the nature of complex things can always be reduced to (explained by) simpler or more fundamental things. ... Holism (from holon, a Greek word meaning entity) is the idea that the properties of a system cannot be determined or explained by the sum of its components alone. ...

Because microevolution can be observed directly, creationists agree that it occurs, though they tend to make a distinction between microevolution, macroevolution, and speciation. Creationism is generally the belief that the universe was created by a deity, or alternatively by one or more powerful and intelligent beings. ... Speciation refers to the evolutionary process by which new biological species arise. ...

Categories: Science stubs | Population genetics Evolutionary biology is a subfield of biology concerned with the origin and descent of species, as well as their change over time, i. ... A speculative phylogenetic tree of all living things, based on rRNA gene data, showing the separation of the three domains, bacteria, archaea and eukaryotes. ... HMS Beagle, from an 1841 watercolour by Owen Stanley. ... Macroevolution refers to evolution that occurs above the level of species. ... Speciation refers to the evolutionary process by which new biological species arise. ... Selection is hierachically classified into natural and artificial selection. ... Genetic drift is the term used in population genetics to refer to the statistical drift over time of allele frequencies in a finite population due to random sampling effects in the formation of successive generations. ... Gene flow (also known as gene migration) is the transfer of genes from one population to another. ... In biology, mutations are changes to the genetic material (usually DNA or RNA). ... We dont have an article called Phenotypic plasticity Start this article Search for Phenotypic plasticity in. ... Anagenesis is the progressive evolution of species involving a change in gene frequency in an entire population rather than a cladogenetic branching event. ... Catagenesis is an archaic term from evolutionary biology referring to evolutionary directions that were considered retrogressive. ... Cladogenesis is an evolutionary splitting event in which each branch and its smaller branches is a clade; an evolutionary mechanism and a process of adaptive evolution that leads to the development of a greater variety of animals or plants. ... The history of evolutionary thought has a long history since the idea of biological evolution has existed since ancient times, but the modern theory wasnt established until the 18th and 19th centuries, with scientists such as Jean-Baptiste Lamarck and Charles Darwin. ... In his lifetime Charles Darwin gained international fame as an influential scientist examining controversial topics. ... The title page of the 1859 edition of On the Origin of Species. ... The modern evolutionary synthesis (often referred to simply as the modern synthesis or the evolutionary synthesis), neo-Darwinian synthesis or neo-Darwinism, generally denotes the combination of Charles Darwins theory of the evolution of species by natural selection, Gregor Mendels theory of genetics as the basis for biological... Population genetics is the study of the distribution of and change in allele frequencies under the influence of the four evolutionary forces: natural selection, genetic drift, mutation, and migration. ... Ecological genetics is the study of genetics (itself a field of biology) from an ecological perspective. ... Human evolution is the part of the theory of evolution by which human beings emerged as a distinct species. ... Molecular evolution is the process of the genetic material in populations of organisms changing over time. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... In biology, systematics is the study of the diversity of organism characteristics, and especially how they relate evolutionarily. ... Evolutionary developmental biology (evolution of development or informally, evo-devo) is a field of biology that compares the developmental processes of different animals in an attempt to determine the ancestral relationship between organisms and how developmental processes evolved. ... This is a list of topics in evolutionary biology and evolution. ... This timeline of evolution of life outlines the major events in the development of life on the planet Earth. ... The timeline of human evolution outlines the major events in the development of our species and the evolution of our ancestors. ...