RE: I am a theist, what do you think of my proof for God existing?
November 19, 2016 at 7:23 pm
(This post was last modified: November 19, 2016 at 7:54 pm by Tonus.
Edit Reason: Misunderstood the original comment
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(November 19, 2016 at 4:19 pm)The Joker Wrote: Evolution, Really? While some molecules do combine to form larger structures such as amino acids, it has been shown that this always results in a mixture of left- and right-handed amino acids that is not used in life. Since this is true, is there some other explanation for how the molecules useful for life might have formed?
Meteorites indicate that liquid water may be the key.
Quote:Researchers examined meteorites dating back more than 4.5 billion years, or older than Earth's existence as a planet, and found that meteorites with the longest exposures to water within had a much stronger left-handed bias.
"We don't have records on Earth, so we look to meteorites," said Daniel Glavin, an astrobiologist at NASA's Goddard Space Flight Center in Maryland. "They tell us a very interesting story that there was a left-handed bias prior to the emergence of life."
Researchers have known about a left-handed bias on Earth for years, but it first came to light for space rocks in a 1997 study of the Murchison meteorite found in Australia. Since then, Glavin and another NASA Goddard astrobiologist examined six meteorites that fit into three different classifications. Half of the meteorites showed the left-handed bias.
"The two meteorites where we saw the highest left-handed enrichment had the longest exposure to water," Glavin told SPACE.com. The evidence suggested that the meteorites had been exposed to liquid water over time periods ranging from 1,000 to 10,000 years.
Glavin added that the most pristine meteorites with little water exposure showed no evidence for the left-handed bias, with water exposure being estimated based on the presence of clays and minerals.
Previous lab experiments have shown that liquid water can amplify any inequality in amino acids, whether a small bias exists toward left-handed or right-handed types — but a neutral experiment should turn up a 50:50 ratio for left-handed and right-handed.
So it seems that water may be the answer since it can bias the results to the extent that some meteorites have only left-handed amino acids. There are still questions, such as the cause of the 100% left-handed bias in meteorites and whether or not conditions on Earth at some point would have produced isolated pockets of left-handed amino acids, or whether some other mechanism is involved.