Have Astronomers Found Life’s Building Blocks?

For at least five decades, proponents of a naturalistic origin of life have been searching for evidence of the RNA world hypothesis. The RNA world is a proposed step in the evolution of life on Earth in which self-replicating RNA molecules preceded genetic material and proteins. Life on Earth appeared suddenly about 3.8 billion years ago. However, evidence for organic molecules that could possibly give rise to RNA is lacking on Earth; thus, astrobiologists believe the building blocks of life must reside in interstellar space.

Precursor Molecules
In 1969, a team of four astronomers led by Lewis Snyder discovered formaldehyde (H₂CO) in an interstellar molecular cloud.¹ In their discovery paper the four astronomers wrote, “H₂CO is the first organic polyatomic molecule ever detected in the interstellar medium and its widespread distribution indicates that processes of interstellar chemical evolution may be much more complex than previously assumed.”² Two months ago, the list of discovered distinct carbonaceous organic polyatomic molecules found in interstellar molecular clouds stood at 152.³

Now, astronomers have added four nitriles to the list.⁴ Nitriles are a class of organic molecules with a cyano group. A cyano group is a carbon atom bound with a triple unsaturated bond to a nitrogen atom. Cyanos are typically very toxic. Sodium cyanide and potassium cyanide are well-known examples.

One of chemistry’s great enigmas is that nitriles are key precursor molecules of the nucleobases, which when joined to a ribose and a phosphate molecule comprise the fundamental building blocks of RNA and DNA molecules. RNA molecules together with DNA molecules, proteins, and lipids are the molecules every organism possesses and without which no life-form can possibly survive.

Discovered Nitriles
A team of thirteen astrobiologists led by Victor Rivilla used the world’s most sensitive millimeter-wave radio telescopes, the IRAM 30-meter and the Yebes 40-meter telescopes in Spain, to search in the giant molecular cloud, G+0.693-0.027, near the center of our galaxy 26,673 light-years away for the spectral signatures of seven nitriles.⁵ The seven nitriles were cyanic acid (HOCN), cyanoformaldehyde (HCOCN), glycolonitrile (HOCH₂CN), cyanoacetaldehyde (HCOCH₂CN), cyanoallene (CH₂CCHCN), propargyl cyanide (HCCCH₂CN), and cyanopropyne (CH₃CCCN). Of the seven, Rivilla’s team detected the following four nitriles: cyanic acid, cyanoallene, propargyl cyanide, and cyanopropyne. They achieved tentative detections of cyanoformaldehyde and glycolonitrile. They did not detect cyanoacetaldehyde. Cyanoallene and propargyl cyanide had been previously detected in the TMC-1 dark molecular cloud, which, at a distance of only 140 light-years is the nearest large molecular interstellar cloud.⁶ The simplest oxygen-bearing nitrile, cyanic acid, was also previously detected in another giant molecular cloud at the galactic center.⁷

The measured abundance levels for the detected nitriles were very low. Even the simplest one, cyanic acid (HOCN), measured rare. Rivilla’s team determined that in G+0.693-0.027 there is only one molecule of cyanic acid for every 6 billion molecules of molecular hydrogen (H₂).⁸ The three non-oxygen-bearing nitriles detected by Rivilla and his colleagues were measured, in each case, at one molecule for every 6–10 billion H₂ molecules.⁹

Origin of Life Implications
The British newspaper, The Telegraph, in the headline of their report on the Rivilla team’s discoveries stated that the “building blocks of life” found by the team “suggests we are not alone.”¹⁰ One of Rivilla’s coauthors, Miguel Requena-Torres, was quoted as saying to Sarah Knapton, science editor for The Telegraph, “We now know that nitriles are among the most abundant chemical families in the universe.”¹¹ By “chemical families,” Requena-Torres had to be referring to precursor molecules for nucleobases and amino acids. Another coauthor, Izaskun Jiménez-Serra, referring to such precursor molecules, said “There are still key missing molecules.”¹²

In the conclusion to their paper, Rivilla’s team noted that nitriles are not a direct precursor to either nucleobases or amino acids. The early Earth’s atmosphere would need to have been chemically reducing and must have contained high amounts of ammonia for amidines to possibly form from nitriles. Several amidines are direct precursors for nucleobases and amino acids. However, as we explained and documented in our book Origins of Life, Earth’s early atmosphere was neither reducing nor did it contain more than a trace amount of ammonia.¹³

What Ravilla’s team found were a few of the hundred-plus molecules that are the “building blocks of the building blocks of the building blocks” of life molecules. They found them at abundance levels far below what is needed for any conceivable naturalistic model for life’s origin. And they found them in an interstellar molecular cloud where the chemical reactions that produce them are counterbalanced by chemical reactions that destroy them.

Thus, Ravilla’s team’s detections do not, as they claim, provide support for the RNA world hypothesis for the origin of life. Rather, their detections provide additional confirmation for what Fazale Rana and I heard Leslie Orgel, the father of the RNA world hypothesis, say in the opening plenary session message at the 2002 International Society for the Study of the Origin of Life conference, “It would be a miracle if a strand of RNA ever appeared on the primitive Earth.”

What seems miraculous from a naturalistic perspective can be explained from a creation perspective as the work of a supernatural Creator. As proclaimed in Psalm 104:24, “How many are your works, Lord! In wisdom you made them all; the earth is full of your creatures.”

Endnotes

1. Lewis E. Synder et al., “Microwave Detection of Interstellar Formaldehyde,” Physical Review Letters 22, no. 13 (March 31, 1969): id. 679, doi:10.1103/PhysRevLett.22.679.
2. Synder et al., “Microwave Detection,” p. 1.
3. Wikipedia, s.v. “List of Interstellar and Circumstellar Molecules,” last edited June 28, 2022, 18:12 (UTC), https://en.wikipedia.org/wiki/List_of_interstellar_and_circumstellar_molecules#.
4. Victor M. Rivilla et al., “Molecular Precursors of the RNA-World in Space: New Nitriles in the G+0.693-0.027 Molecular Cloud,” Frontiers in Astronomy and Space Sciences: Section Astrochemistry (July 8, 2022), doi:10.3389/fspas.2022.876870.
5. Rivilla et al., “Molecular Precursors of the RNA-World.”
6. Brett A. McGuire et al., “Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH₂CN) in TMC-1,” Astrophysical Journal Letters 900, no. 1 (2020): id. L10, doi:10.3847/2041-8213/aba632; N. Marcelino et al., “A Study of C₄H₃N Isomers in TMC-1: Line by Line Detection of HCCCH₂CN,” Astronomy & Astrophysics 646 (February 12, 2021): id. L9, doi:10.1051/0004-6361/202040177.
7. S. Brünken et al., “Interstellar HOCN in the Galactic Center Region,” Astronomy & Astrophysics 516 (June-July 2010): id. A109, doi:10.1051/0004-6361/200912456.
8. Rivilla et al., “Molecular Precursors of the RNA-World.”
9. Rivilla et al., “Molecular Precursors of the RNA-World.”
10. Sarah Knapton, “Building Blocks of Life Found Floating in Milky Way in Discovery that Suggests We Are Not Alone,” The Telegraph (July 10, 2022), https://www.telegraph.co.uk/news/2022/07/10/building-blocks-life-found-floating-milky-way-discovery-suggests/.
11. Knapton, “Building Blocks of Life Found.”
12. Knapton, “Building Blocks of Life Found.”
13. Fazale Rana and Hugh Ross, Origins of Life (Covina, CA: RTB Press, 2014), 101–104, 106–107.