'Ancestral Eve' crystal may explain origin of life's left-handedness

'Ancestral Eve' crystal may explain origin of life's left-handedness
Molecules of aspartic acid with a left-handed orientation, shown in crystal form, could be the "ancestral Eve" of all amino acids -- the building blocks of proteins -- in life on Earth. Credit: American Chemical Society

Scientists are reporting discovery of what may be the "ancestral Eve" crystal that billions of years ago gave life on Earth its curious and exclusive preference for so-called left-handed amino acids. Those building blocks of proteins come in two forms — left- and right-handed — that mirror each other like a pair of hands. Their study, which may help resolve one of the most perplexing mysteries about the origin of life, is in ACS' Crystal Growth & Design.

Tu Lee and Yu Kun Lin point out that conditions on the primordial Earth held an equal chance of forming the same amounts of left-handed and right-handed . Nevertheless, when the first forms of life emerged more than 3 billion years ago, all the amino acids in the proteins had the left-handed configuration. That pattern continued right up to modern plants and animals.

The scientists used mixtures of both left- and right-handed aspartic acid (an amino acid) in laboratory experiments to see how temperature and other conditions affected formation of of the material. They found that under conditions that could have existed on primitive Earth, left-handed aspartic acid crystals could have formed easily and on a large scale. "The aspartic acid crystal would then truly become a single mother crystal: an ancestral Eve for the whole left-handed population," the article notes.

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More information: "The Origin of Life and the Crystallization of Aspartic Acid in Water", Crystal Growth & Design
Citation: 'Ancestral Eve' crystal may explain origin of life's left-handedness (2010, April 21) retrieved 21 September 2019 from https://phys.org/news/2010-04-ancestral-eve-crystal-life-left-handedness.html
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User comments

Apr 21, 2010
Another thought: God placed the left-handed in us to begin with. Much easier to believe, and makes much more sense.

...sure, lol. the process that created life is so much harder to believe and grasp than the origins of some whimsical super-being that created everything. (well its known that it was thought up by man). Diety belief is an irrational extra step.
There is no explaining dieties and therefore they
are the most complete nonsence of all. The very definition of faith is to believe in that which is unexplainable and irrational- quite literally 'anti-sense'.

Apr 22, 2010
Don't feed the trolls (or ignorant for that matter)

Apr 25, 2010
Very interesting article, thanks.

Apr 26, 2010
So why does the left handed acid crystalise more easily than the right handed? This could go either way, the right handed left in solution could be available to organisms. Also this experiment should make sure of absolute cleanliness, they would not want a molecule of left handed amino acid protein from a current organism from seeding these crystals preferentially.

May 01, 2010
This physorg article doesn't explain why left handed aspartic acid crystalize more easily. I hope the authors' article has more detail.

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