Aards leven afkomstig van sterren - pan-spermia theorie wint terrein

[C2C]

Public release date: 13-Jun-2008
[ Print Article | E-mail Article | Close Window ]

Contact: Colin Smith
[email protected]
44-020-759-46712
Imperial College London

Scientists confirm that parts of earliest genetic material may have come from the stars
Scientists have confirmed for the first time that an important component of early genetic material which has been found in meteorite fragments is extraterrestrial in origin, in a paper published on June 15, 2008

Scientists have confirmed for the first time that an important component of early genetic material which has been found in meteorite fragments is extraterrestrial in origin, in a paper published on 15 June 2008.

The finding suggests that parts of the raw materials to make the first molecules of DNA and RNA may have come from the stars.

The scientists, from Europe and the USA, say that their research, published in the journal Earth and Planetary Science Letters, provides evidence that life's raw materials came from sources beyond the Earth.

The materials they have found include the molecules uracil and xanthine, which are precursors to the molecules that make up DNA and RNA, and are known as nucleobases.

The team discovered the molecules in rock fragments of the Murchison meteorite, which crashed in Australia in 1969.

They tested the meteorite material to determine whether the molecules came from the solar system or were a result of contamination when the meteorite landed on Earth.

The analysis shows that the nucleobases contain a heavy form of carbon which could only have been formed in space. Materials formed on Earth consist of a lighter variety of carbon.

Lead author Dr Zita Martins, of the Department of Earth Science and Engineering at Imperial College London, says that the research may provide another piece of evidence explaining the evolution of early life. She says:

"We believe early life may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations."

Between 3.8 to 4.5 billion years ago large numbers of rocks similar to the Murchison meteorite rained down on Earth at the time when primitive life was forming. The heavy bombardment would have dropped large amounts of meteorite material to the surface on planets like Earth and Mars.

Co-author Professor Mark Sephton, also of Imperial's Department of Earth Science and Engineering, believes this research is an important step in understanding how early life might have evolved. He added:

"Because meteorites represent left over materials from the formation of the solar system, the key components for life -- including nucleobases -- could be widespread in the cosmos. As more and more of life's raw materials are discovered in objects from space, the possibility of life springing forth wherever the right chemistry is present becomes more likely."

###

For further information please contact:

Colin Smith
Press Officer
Imperial College London
Email: [email protected]
Tel: +44 (0)207 594 6712
Out of hours duty press officer: +44 (0)7803 886 248

Dr Zita Martins
Department of Earth Science and Engineering
South Kensington Campus
Imperial College London
London SW7 2AZ, UK
Tel: +44 (0)20 7594 9982
Fax: +44 (0)20 7594 7444
Email: [email protected]
http://www.imperial.ac.uk/people/z.martins

Notes to editors:

1. "Extraterrestrial nucleobases in the Murchison meteorite", Earth and Planetary Science Letters, Sunday 15 June 2008 (Print publication)

A full copy of the research can be downloaded at: http://dx.doi.org/10.1016/j.epsl.2008.03.026

Zita Martins (1,2), Oliver Botta (3,4,5), Marilyn L. Fogel (6), Mark A. Sephton (2), Daniel P. Glavin (3), Jonathan S. Watson (7), Jason P. Dworkin (3), Alan W. Schwartz (8), Pascale Ehrenfreund (1,3)
(1) Astrobiology Laboratory, Leiden Institute of Chemistry, 2300 RA Leiden, The Netherlands
(2) Department of Earth Science and Engineering, Imperial College, London, SW7 2AZ, UK
(3) NASA Goddard Space Flight Center, Code 699, Greenbelt, MD 20771, USA
(4) Goddard Earth Sciences and Technology Center, University of Maryland Baltimore, County, Baltimore, MD 21228, USA
(5) International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland
(6) GL, Carnegie Institution of Washington, Washington, DC 20015, USA
(7) Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
(8) Radboud University Nijmegen, 6525 ED, Nijmegen,The Netherlands

2. About Imperial College London

Imperial College London - rated the world's fifth best university in the 2007 Times Higher Education Supplement University Rankings - is a science-based institution with a reputation for excellence in teaching and research that attracts 12,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture. Website: www.imperial.ac.uk

http://www.eurekalert.org/pub_releas...-sct061308.php

-------------

Snelle cut & paste want ik moet naar de GB.

[Pieke]

Oorspronkelijk geplaatst door C2C

Snelle cut & paste want ik moet naar de GB.

die is nog open tot 6, waarom de tijd niet nemen om er een mening bij te geven

anyway, ik vraag me af hoe die aminozuren een impact op Aarde kunnen overleven?

tot ik iets anders tegenkom, blijf ik bij de hydrothermale schoorstenen. Zwavel, meer heeft het niet nodig...

[circe]

dubbel

http://forum.politics.be/showthread.php?t=107610

(waarom zet jij dit wetenschappelijk onderzoek in feite bij godsdienst?)

[Johan Bollen]

Scientists confirm that parts of earliest genetic material may have come from the stars

Daarmee wordt dus niets gezegd eigenlijk. Dit soort van dingen krijg je als wetenschap en entertainement elkaar ontmoeten.

[C2C]

Oorspronkelijk geplaatst door Johan Bollen

Daarmee wordt dus niets gezegd eigenlijk. Dit soort van dingen krijg je als wetenschap en entertainement elkaar ontmoeten.

Dat er uracil en xanthine in een meteorietfragment wordt ontdekt is misschien voor u entertainment, maar voor de wetenschap is dit toch vrij belangrijk, omdat het de hypothese sterkt die zegt dat meteorieten aan de basis van de verspreiding van het leven liggen.

Of wist u misschien al dat er uracil en xanthine in aardse meteorieten zat?

En zo ja, waarom heeft u dat dan niet eerder aan de wetenschappelijke wereld bekendgemaakt?

[C2C]

Oorspronkelijk geplaatst door circe

waarom zet jij dit wetenschappelijk onderzoek in feite bij godsdienst?

Omdat scheppingsverhalen toch vrij centraal staan in de meeste religies.

[exodus]

Weeral propaganda om buitenaards leven aannemelijker te maken. Ze zijn bezig met het "molden" van de publieke opinie in die richting.

[straddle]

Oorspronkelijk geplaatst door circe

dubbel

http://forum.politics.be/showthread.php?t=107610

(waarom zet jij dit wetenschappelijk onderzoek in feite bij godsdienst?)

En ik had er elders ( bij evolutietheorie is een geloof) ook al melding van gemaakt (dacht ook dat het daar thuishoorde eerst), met een linkje naar een beeldverslag van channel 4 nieuws...

http://forum.politics.be/showpost.ph...postcount=5084

[shaddy]

geef mij maar het boek : geometrie van de schepping.

[kiko]

Oorspronkelijk geplaatst door exodus

Weeral propaganda om buitenaards leven aannemelijker te maken. Ze zijn bezig met het "molden" van de publieke opinie in die richting.

Bijlange niet.

Het is gewoon een theorie als een ander, en als het verspreiden van deze theorie al een bepaald doel heeft, is het enkel het losweken van budgetten.

[Wautd]

Space

Study: Life's Raw Material Came from Space
By Clara Moskowitz
Staff Writer
posted: 13 June 2008
03:55 pm ET

Editor's Note: This story was updated at 3:45 p.m. EDT.

We may all be aliens, it seems.

Some of the building blocks of life on Earth came from space, according to a new study of molecules in meteorite fragments.

The study confirmed that some of the raw material for DNA and RNA found in a meteorite did not contaminate the rock after it landed on Earth, but actually originated in space.

The materials in question are the molecules uracil and xanthine, which are precursors to the compounds that make up DNA and RNA, and are known as nucleobases.

"We believe early life may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations," said the study's lead author, Zita Martins, a researcher in the Department of Earth Science and Engineering at Imperial College London.

Martins and her colleagues detailed their findings in the June 15 issue of the journal Earth and Planetary Science Letters.

The team discovered the molecules in rock fragments of the Murchison meteorite, which crashed in Australia in 1969. The scientists analyzed the genetic building blocks and found that they contain a heavy form of carbon which could only have been formed in space. Materials formed on Earth are made of a lighter type of carbon.

The two molecules in this study are only a few of the organic molecules that have been detected in the famous Murchison meteorite, said David Deamer, a chemist at the University of California, Santa Cruz.

"There are about 70 different amino acids in the Murchison meteorite," Deamer told SPACE.com. "About six or so are the same kinds of amino acids associated with life on Earth."

Uracil is one of the four base molecules of RNA, so is vital for life.

Just because the molecules found on this meteorite and others came from space, doesn't mean the same compounds weren't also independently synthesized on Earth, Deamer pointed out. Scientists are unsure how many of the building blocks of life on Earth originated on this planet, and how many came from beyond.

"We don't know the answer yet," he said. "Most people would say that both contributed to the organic compounds available on Earth, but we don't know with certainty how much of one compared to the other."

Many space rocks similar to the Murchison meteorite rained down on Earth between 3.8 and 4.5 billion years ago, when primitive life was forming. The heavy bombardment would have dropped large amounts of meteorite material to the surface on planets such as Earth and Mars.

Martins and her colleagues say their discovery may help shed light on how life first evolved in our solar system.

"Because meteorites represent leftover materials from the formation of the solar system, the key components for life - including nucleobases - could be widespread in the cosmos," said co-author Mark Sephton, a professor of Earth science and engineering at Imperial College London. "As more and more of life's raw materials are discovered in objects from space, the possibility of life springing forth wherever the right chemistry is present becomes more likely."