Related topics: dna sequences

Hidden life revealed inside dinosaur bones

One of the tricks you learn hunting dinosaurs in Canada is to look for orange. Dinosaur bones are dull browns, tans, and greys. But in the middle of the drab sandstones of the badlands—a dry landscape where wind and water ...

Island cores unravel mysteries of ancient Maltese civilisation

The mysteries of an ancient civilisation that survived for more than a millennium on the island of Malta—and then collapsed within two generations—have been unravelled by archaeologists who analysed pollen buried deep ...

Dark centers of chromosomes reveal ancient DNA

Geneticists exploring the dark heart of the human genome have discovered big chunks of Neanderthal and other ancient DNA. The results open new ways to study both how chromosomes behave during cell division and how they have ...

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Ancient DNA

Ancient DNA can be loosely described as any DNA recovered from biological samples that have not been preserved specifically for later DNA analyses. Examples include the analysis of DNA recovered from archaeological and historical skeletal material, mummified tissues, archival collections of non-frozen medical specimens, preserved plant remains, ice and permafrost cores, Holocene plankton in marine and lake sediments, and so on. Unlike modern genetic analyses, ancient DNA studies are characterised by low quality DNA. This places limits on what analyses can achieve. Furthermore, due to degradation of the DNA molecules, a process which correlates loosely with factors such as time, temperature and presence of free water, upper limits exist beyond which no DNA is deemed likely to survive. Current estimates suggest that in optimal environments, i.e environments which are very cold, such as permafrost or ice, an upper limit of max 1 Million years exists. As such, early studies that reported recovery of much older DNA, for example, from Cretaceous dinosaur remains, have been proven to be wrong, with results stemming from sample or extract contamination, as opposed to authentic extracted DNA.

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