Science require us to be able to explain a process that will bring us to the product.
As I understand it, the presence of chemical compounds in nature do not guarantee that the process will take place. That there are chemicals in nature and all around should not immediately be connected to DNA. DNA and the cell in which it is contained is far too complex and is a long way from the mere presence of chemicals that make it up to become a code set.
So if the raw materials are all around, what and where is the factory that will process these to become components of the finished product we call a living cell? That there are materials for the software, how about the materials for the hardware? As I understand it, the container of a cell is made up of sugar compounds; and there is more than that, the operating system of the cell is an entirely different lot from the DNA.
Which came first, the container, the operating system, or the application? There are a lot of chemical compounds that have to come together before we can begin to connect guanines in nature to DNA.
NASA researchers say they have found evidence that some building blocks of DNA found in meteorites were likely created in space.
The finding offers more support to the theory that the origin of life may have come from elsewhere in the universe, handily delivered by a meteorite long ago.
Components of DNA have been found in meteorites since the Golden Age of space exploration in the 1960s. But researchers were never quite sure whether they came from outer space — or were just evidence of contamination on the trip to Earth.
For the first time, researchers say they’re confident it’s the former, not the latter.
To find out, the researchers ground up samples of twelve carbon-rich meteorites, nine of which were recovered from Antarctica.
Using a solution of formic acid, the researchers extracted samples and ran them through a liquid chromatograph, which separates a mixture of compounds. With a mass spectrometer — which helps determine the chemical structure of compounds — they found the presence of adenine and guanine, two nucleobases (”rungs” of the ladder, if you will) of DNA.
They also found hypoxanthine and xanthine, which aren’t in DNA but used in other biological processes.
In two of the meteorites, the researchers also found trace amounts of purine, 2,6-diaminopurine and 6,8-diaminopurine. While two of the three are almost never used in biology, all three molecules are variants on the same core molecule that makes up the found nucleobases. Because of this relation, they’re called “nucleobase analogs,” and the fact that they’re never present in biology help confirm that the researchers’ findings weren’t the product of terrestrial contamination.
Just to be safe, the researchers analyzed an eight-kilogram (17.64-lb.) sample of ice from Antarctica and found the same two nucleobases, plus hypoxanthine and xanthine, but at much lower concentrations than in the meteorites. Further, none of the nucleobase analogs were detected in the ice sample, helping to prove that contamination wasn’t present.
Which means that asteroids are behaving like “chemical factories cranking out prebiotic material,” said lead author Michael Callahan, a researcher at NASA’s Goddard Space Flight Center, in a statement.
To add to it all, the researchers were able to determine that all the found nucleobases — biological and non-biological — were produced in a completely non-biological reaction.
“In the lab, an identical suite of nucleobases and nucleobase analogs were generated in non-biological chemical reactions containing hydrogen cyanide, ammonia, and water,” Callahan said. “This provides a plausible mechanism for their synthesis in the asteroid parent bodies, and supports the notion that they are extraterrestrial.”
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