0
   

Why organic molecules in meteorites are remains of life

 
 
Reply Sat 3 Sep, 2011 05:57 am
Amino acid molecules produced in the lab are 50% left handed and 50% right handed. However, amino acids in fossils can be uneven-handed (over 50% left-handed, for example). This unevenness or excess of left-handed amino acids is a sure sign of past life (note 1). This sign of past life is found in organic molecules in meteorites (notes 2, 3). So, organic molecules in meteorites are post-biotic fossils.

Note 1: “Homochirality probably constitutes the most reliable indicator of the biological vs. abiotic origin of organic molecules.” http://www.esa.int/SPECIALS/ExoMars/SEMK39JJX7F_0.html

Note 2:"Fragments of the Tagish Lake meteorite contain amino acids that are predominantly left-handed, as in life." http://www.panspermia.org/whatsnew65.htm#110613

Note 3: “In the new research, the team reports finding excess left-handed isovaline (L-isovaline) in a much wider variety of carbon-rich meteorites.” http://www.nasa.gov/topics/solarsystem/features/left_hand_aminoacids.html

Added on Sept. 3, 2011:
Explanation on fossils’ amino acids

When organisms die and form fossils, the percentage of their left-handed amino acids decrease gradually from 100%, then fluctuates around 50 % until the percentage finally becomes stable at 50%. Abiotic amino acids always are 50% left handed. So, small variations from 50% of left-handed standard (protein) amino acids indicate past life of the sample material.

Even-handed amino acids do not prove past life as they are found both in non-life, and in not-well-preserved fossils, and very ancient fossils. Uneven-handed standard amino acids prove origin in life as they are found only in well-preserved fossils.

Ref.: http://en.wikipedia.org/wiki/Amino_acid_dating#Principle
  • Topic Stats
  • Top Replies
  • Link to this Topic
Type: Discussion • Score: 0 • Views: 1,356 • Replies: 1
No top replies

 
rosborne979
 
  1  
Reply Sat 3 Sep, 2011 11:19 am
@bewildered,
The article in note 3 explains that life should have been able to use right handed molecules just as well as left handed. So there is an effort under way to try to figure out why life (on earth) uses left handed molecules.

The article notes that there is evidence that left handedness is a dominant condition in meteorites which form amino acids naturally. So there is a possibility that the left-handedness of amino acids in earth organisms is simply because life arose from predominantly left handed raw materials (from these meteorites).

The assumption seems to be that the left-handed mollecular bias is coming about naturally and chemically (not through biology), and not the other way around (remnants of biology on the asteroids resulting in left-handed molecular dominance).

None of these links/documents indicates that organic molecules in meteorites are the remains of life. They simply make note of the left-handedness of molecules and the dominance of that feature on some meteorites. You are still making an assumption that those dominant percentages are the RESULT of life and not the FOUNDATION of life.

(good links by the way, a step up from your previous lunacy)
0 Replies
 
 

Related Topics

T'Pring is Dead - Discussion by Brandon9000
Another Calif. shooting spree: 4 dead - Discussion by Lustig Andrei
Before you criticize the media - Discussion by Robert Gentel
Fatal Baloon Accident - Discussion by 33export
The Day Ferguson Cops Were Caught in a Bloody Lie - Discussion by bobsal u1553115
Robin Williams is dead - Discussion by Butrflynet
Amanda Knox - Discussion by JTT
 
  1. Forums
  2. » Why organic molecules in meteorites are remains of life
Copyright © 2024 MadLab, LLC :: Terms of Service :: Privacy Policy :: Page generated in 0.04 seconds on 04/25/2024 at 04:30:03