Jurassic Park will never be opened
The half-life of DNA is 521 years
Dmitry Tselikov, Compulenta
Some researchers take the liberty to claim that even today it is possible to isolate dinosaur DNA, because no one knows how long it takes for the genetic material to disintegrate...
More precisely, I did not know, because the study of fossils from New Zealand allowed us to approximately establish the half-life of DNA and finally dispelled hopes for cloning tyrannosaurus.
After cell death, enzymes begin to destroy the bonds between the nucleotides that form the basis of DNA. The decay is accelerated by microorganisms, and in the long term, water is responsible for the degradation of most bonds. Groundwater is ubiquitous, so DNA in bones, in theory, should decay at an increasing rate.
It turned out to be difficult to determine this rate, because it is rarely possible to find a large number of DNA-containing fossils that would allow for comparison. Even worse, the rate of decay is influenced by environmental variables: temperature, the degree of biochemical activity of microorganisms, the rate of oxygenation, etc.
But paleogenetics under the leadership of Morten Allentoft (pictured from Nature News – VM) from the University of Copenhagen (Denmark) and Michael Bunce from Murdoch University (Australia) were able to obtain 158 DNA-containing leg bones belonging to three species of extinct giant moa birds. The remains were from 600 to 8,000 years old, they were found at three sites within 5 km of each other, and subsequently they were stored in almost identical conditions at a temperature of 13.1 °C.
Comparing the age and degree of degradation of the genetic material of bones, the researchers calculated that the half-life of DNA is 521 years. In other words, during this time, half of the bonds between the nucleotides are destroyed, then half of the remaining ones disintegrate, and so on.
Scientists believe that even at a temperature ideal for the preservation of genetic material (-5 ° C), each bond will be destroyed in a maximum of 6.8 million years (at a negative temperature, the half-life of DNA can reach 158 thousand years). In reality, DNA ceases to be readable much earlier: it takes about 1.5 million years for the DNA strands to become too short and stop giving meaningful information.
Therefore, the talk that it would be good to isolate the DNA of dinosaurs or insects trapped in an amber trap can be stopped.
At the same time, a number of experts would like to look at similar studies of fossils from permafrost, because it is obvious that bones stored under different conditions can give a different result. Indeed, the analysis of the remains of moa showed that age differences are responsible for only 38.6% of the discrepancies in the degree of DNA degradation. Obviously, the speed is influenced by the storage conditions of the sample after excavation, and the chemical composition of the soil, and even the time of year in which the animal died.
The oldest DNA today belongs to insects and plants found in ice aged from 450 to 800 thousand years.
The results of the study are published in the journal Proceedings of the Royal Society B (Allentoft et al., The half-life of DNA in bone: measuring decay kinetics in 158 dated fossils).
Prepared based on Nature News: DNA has a 521-year half-life.
Portal "Eternal youth" http://vechnayamolodost.ru11.10.2012