Search results
Results from the WOW.Com Content Network
Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants. The most famous example of adaptive radiation in plants is quite possibly the Hawaiian silverswords , named for alpine desert-dwelling Argyroxiphium species with long, silvery leaves that live for up to 20 years before growing a single ...
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 ...
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.
Amongst other causes, this can be due to physical, chemical, infectious, biological, nutritional or immunological factors. Cell damage can be reversible or irreversible. Depending on the extent of injury, the cellular response may be adaptive and where possible, homeostasis is restored. [1]
Allopatric speciation (from Ancient Greek ἄλλος (állos) 'other' and πατρίς (patrís) 'fatherland') – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model [1]: 86 – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.
Amid concerns about Russian President Vladimir Putin’s recent nuclear threats came a bit of startling news: The U.S. Department of Health and Human Services said Tuesday that it spent $290 ...
Radioresistance is the level of ionizing radiation that organisms are able to withstand.. Ionizing-radiation-resistant organisms (IRRO) were defined as organisms for which the dose of acute ionizing radiation (IR) required to achieve 90% reduction (D10) is greater than 1,000 gray (Gy) [1]
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.