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An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, [1] that may or may not be associated with an increase in morphological disparity. [2] A significantly large and diverse radiation within a relatively short geologic time scale (e.g. a period or epoch ) is often referred to as an ...
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions or opens new environmental niches.
The Great Ordovician Biodiversification Event (GOBE) was an evolutionary radiation of animal life throughout [1] the Ordovician period, 40 million years after the Cambrian explosion, [2] whereby the distinctive Cambrian fauna fizzled out to be replaced with a Paleozoic fauna rich in suspension feeder and pelagic animals.
Radiation exposure through ionizing radiation (IR) affects a variety of processes inside of an exposed cell. IR can cause changes in gene expression, disruption of cell cycle arrest, and apoptotic cell death. The extent of how radiation effects cells depends on the type of cell and the dosage of the radiation.
In evolutionary biology, a key innovation, also known as an adaptive breakthrough or key adaptation, is a novel phenotypic trait that allows subsequent radiation and success of a taxonomic group. Typically they bring new abilities that allows the taxa to rapidly diversify and invade niches that were not previously available.
Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth.
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] 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. [3]
Macroevolution addresses the evolution of species and higher taxonomic groups (genera, families, orders, etc) and uses evidence from phylogenetics, [5] the fossil record, [9] and molecular biology to answer how different taxonomic groups exhibit different species diversity and/or morphological disparity.