by Elena Kovachich
Moscow (Voice of Russia) Apr 11, 2012
A group of scientists from the Altay University became pioneers in decoding the DNA of ancient Metasequoia, known as dawn redwood. The remains of the plant were discovered in the north of the Canadian Arctic Archipelago. The remains are said to be aged about 50 million years.
It turned out that the relict does not differ much from the contemporary redwood which can be found in China. The fact that no major DNA mutations have taken place over such a huge period of time allows the scientists have a look at the process of evolution from a different angle.
The DNA decoded at the Altay University is the oldest ever found. The research was carried out using several branches of the relict tree which remains were found in northern Canada at the end of the 19th century.
Millions years ago the land not far from the North Pole were not covered with snow but looked like tropical forests full of metasequoia trees which comprise the cypress subfamily. Nowadays such forests still can be found in the Sichuan Hollow in China.
Scientists at the Altay University decided to compare their gene type with that of the ancient relict to see whether any changes have occurred. The task turned impossible to fulfill because all organic molecules were destroyed, genetic biologist Yevgeny Davydov told the VoR: "You can extract DNA only from young species aged not more than 10 years.
Once an attempt to extract DNA from a century-old herbarium proved successful, which was a true sensation in the world of science. A new method of DNA extraction was invented at the Altay University: it relies on brand new methods."
The scientists managed not just to extract DNA from the relict tree but also to learn that no major DNA mutations had taken place during millions of years.
"The study showed that metasequoia evolves very slowly: only several mutations per 1,000 nucleotides over 50 million years. This is a very slowly evolution process. Now we can affirm that the rate of evolution must be approached in different ways. This offers a new take on the molecular clock hypothesis.
First suggested by American scientist Masatoshi Nei, the molecular clock hypothesis suggests that within given gene, mutations accumulate at an approximately equal rate in all evolutionary lineages. So, knowing the number of nucleotide changes we may define when this or that species appeared."
The biologists at the Altay University say that this approach cannot be attributed to the evolutionary process: some plants show major alterations with time, while other can preserve its original gene type for centuries. This is exactly the case with this 50-million-year-old metasequoia.
Recently, a group of biologists from the Soil Physics Chemistry and Biology Institute outside Moscow grew the seeds of Bladder Campion which had remained in permafrost soil for 30,000 years.
A plant which they grew and its contemporary analogue differed only in flowers. It adds new evidence to the molecular clock hypothesis, urging genetic biologists to take a brand new approach to the history of life on Earth.
Source: Voice of Russia
Forestry News - Global and Local News, Science and Application
Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.
Scientists forecast forest carbon loss
Boston MA (SPX) Apr 11, 2012
When most people look at a forest, they see walking trails, deer yards, or firewood for next winter. But scientists at the Harvard Forest and Smithsonian Institution take note of changes imperceptible to the naked eye - the uptake and storage of carbon. What they've learned in a recent study is that an immense amount of carbon is stored in growing trees, but if current trends in Massachuse ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|