User:Abyssal/Portal:Devonian
IntroductionThe The first significant myriapods, arachnids and hexapods, also became well-established early in this period, after beginning their colonization of land at least from the Ordovician period. (Full article... )
Selected article on the Devonian world and its legacies specialize in certain types of host. About 5,000 viruses have been described in detail, although there are millions of different types. Viruses are found in almost every ecosystem on Earth and are the most abundant type of biological entity. The study of viruses is known as virology .
Virus particles (known as virions) consist of two or three parts: i) the genetic material made from either DNA or RNA, long molecules that carry genetic information; ii) a proteincoat that protects these genes; and in some cases iii) an envelope of lipids that surrounds the protein coat when they are outside a cell. The shapes of viruses range from simplehelical and icosahedral forms to more complex structures. The average virus is about one one-hundredth the size of the average bacterium.
The origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids—pieces of DNA that can move between cells—while others may have evolved from bacteria. Viruses are considered by some to be a life form, because they carry genetic material, reproduce, and evolve through natural selection. However they lack key characteristics (such as cell structure) that are generally considered necessary to count as life, so whether or not viruses are truly alive is controversial. (see more... )
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Selected article on the Devonian in human science, culture and economicssee more... )
GeochronologyEpochs - Late Devonian Ages - Lochkovian - Pragian - Emsian - Eifelian - Givetian - Frasnian - Famennian Events - Karoo Ice Age Landmasses - Euramerica - Gondwana Bodies of water Proto-Tethys - Rheic Ocean Animals - Trilobites Fungi - Prototaxites Plants - Progymnosperms Fossil sites - Grenfell fossil site History - The Great Devonian Controversy SubcategoriesQuality ContentThings you can do
Current Devonian FACs - none currently Related contentAssociated WikimediaThe following Wikimedia Foundation sister projects provide more on this subject:
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