Entire genome of extinct human (Denisovans) decoded from fossil
In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The DNA sequences showed that this individual came from a previously unknown group of extinct humans that have become known as Denisovans. Together with their sister group the Neandertals, Denisovans are the closest extinct relatives of currently living humans.
The Leipzig team has now developed sensitive novel techniques which have allowed them to sequence every position in the Denisovan genome about 30 times over, using DNA extracted from less than 10 milligrams of the finger bone. In the previous draft version published in 2010, each position in the genome was determined, on average, only twice. This level of resolution was sufficient to establish the relationship of Denisovans to Neandertals and present-day humans, but often made it impossible for researchers to study the evolution of specific parts of the genome. The now-completed version of the genome allows even the small differences between the copies of genes that this individual inherited from its mother and father to be distinguished. This Wednesday the Leipzig group makes the entire Denisovan genome sequence available for the scientific community over the internet.
“The genome is of very high quality”, says Matthias Meyer, who developed the techniques that made this technical feat possible. “We cover all non-repetitive DNA sequences in the Denisovan genome so many times that it has fewer errors than most genomes from present-day humans that have been determined to date”.
Researchers have now been able to sequence the entire Denisova genome using 10 milligram of a finger bone fragment that was found in the Denisova-Cave in Southern Sibiria
This genome is the first complete genome sequence of an archaic human group. A big step in the study of study of extinct forms of humans. Biologists who specialize in human evolution will be able to use comparisons between the Denisovans and the modern human genome to discover genetic changes in the development of modern humans. Including the development of culture and technology. In terms of the evolution of modern mammals all of this took place in the relatively past. Ancestors to modern humans left Africa and spread around the world just 100,000 years ago.
Space junk to be cleaned up by Swiss ‘janitor satellite’
The year 2011 was full of reports that space debris was re-entering the atmosphere and raining down on Earth. First came a 12,500-pound decommissioned satellite, which fell in the Pacific Ocean, then a mysterious space ball, which dropped on Namibia, and finally pieces of a Russian space probe crashed somewhere off Chile’s coastline. By September of last year, a report from the National Research Council said, ominously, that space debris has reached a “tipping point.”
But the ever-tidy Swiss think they have a solution to all the old satellites, broken rocket ships or other junk humans have left out in space. On Wednesday, Swiss scientists announced plans to launch a “janitor satellite,” designed, as its name implies, to clean up space debris, the Associated Press reports.
An artist’s impression of a CleanSpace One satellite chasing a piece of debris. (AFP/GETTY IMAGES/Swiss Space Center )
There are an estimated 500,000 pieces of debris orbiting Earth, according to NASA. That space junk, rather big or as small as a bolt, travels at about 17,500 mph. The space janitor would grab a piece of junk or two and then guide them into the earth;s atmosphere where they would burn up. It will be a few years before the space janitor is ready for launch. The first two targets are said to old Swiss satellites.
Dead for 32,000 Years, an Arctic Plant Is Revived
A plant has been generated from the fruit of the narrow-leafed campion. It is the oldest plant by far to be grown from ancient tissue.
…Many plants can be propagated from a single adult cell, and this cloning procedure worked with three of the placentas, the Russian researchers report. They grew 36 ancient plants, which appeared identical to the present day narrow-leafed campion until they flowered, when they produced narrower and more splayed-out petals. Seeds from the ancient plants germinated with 100 percent success, compared with 90 percent for seeds from living campions.
The Russian team says it obtained a radiocarbon date of 31,800 years from seeds attached to the same placenta from which the living plants were propagated.
The researchers suggest that special circumstances may have contributed to the remarkable longevity of the campion plant cells. Squirrels construct their larders next to permafrost to keep seeds cool during the arctic summers, so the fruits would have been chilled from the start. The fruit’s placenta contains high levels of sucrose and phenols, which are good antifreeze agents.
The narrow-leafed campion photo by Svetlana Yashina
There is still some doubt about this discovery and thus the plant being from a seed reported as old as 32,000 years. So we’ll have to watch for further reports. previously the oldest plant from an ancient seed was from a date palm grown from a seed some 2,000 years old that was recovered from the ancient fortress of Masada in Israel.
I did not have a science question last week so this is the question and the answer. I’m using this question because of a news report I read that many adults do not know the answer. How long does it take for the earth to orbit the sun? The Earth’s orbit is the motion of the Earth around the Sun, at an average distance of about 150 million kilometers(93,205,678.8 miles), every 365.256363 mean solar days or one year. For those 18% of US citizens who believe the sun revolves around the earth, try to keep up. The fact that the earth revolves around the sun has been an established fact for over 500 years.
Goldman Sachs Admits Record Speculation To Blame For Skyrocketing Gas Prices. It seems that $5 a gallon gas is inevitable.
Rabbit gets a puppy kiss - ick dog slobber.
The Baillon’s Crake (Porzana pusilla) is a very small waterbird of the family Rallidae. Until modern drainage projects the Crake was found in Great Britain. It’s current breeding range includes sedge beds in Europe, mainly in the east, and across Asia.
