AUG 14, 2020 8:34 AM PDT

Cosmic Rays Might Have Played a Role in Shaping Our Genetic Materials

WRITTEN BY: Daniel Duan

(Pixabay/Qimono)

DNA, whose signature double helix structure scored Watson and Crick (and Frankland presumably according to many) a Nobel prize, lies the center of the genetic coding system of life on Earth. Its handedness, or chirality in chemistry term, is the result of eons-worth evolutionary processes, which according to a recent study, could have involved a "heavenly" factor - the cosmic rays that is.

Noemie Globus and Roger Blandford, astrophysicists from New York University and Stanford University, reported their simulation-backed hypothesis on why we end up having mostly right-handed DNAs. 

Louis Pasteur, the 19th-century pioneer of bacteriology, was among the first to notice the innate connections between organic life forms and the universe, thanks to his meticulous exploration of the structural asymmetry in organic compounds.

The right-handed helix (also known as the "B-form") is the most common structure of DNA. Z-form DNA, on the other hand, represents an alternative conformation to its popular sibling. The left-handed double-helical structure winds to the left in a zigzag pattern.

Nucleotide and their polymers aren't the only biomolecules that are chiral. Amino acids, the building blocks for peptides and proteins, also have one or more chiral centers. Like DNA, their polymeric structure is also chiral due to the chirality of the individual monomers.

The astrophysics duo hypothesized that the bombardment of polarized cosmic rays on the surface of Earth over the course of billions of years propagates a subtle yet highly accumulative trend, which leads to chiral bias in the biological molecules. 

How Space Might Have Shaped Our DNA (SciShow)

Take muon for example, the elementary particle makes up a large portion of cosmic radiation. Like a "chunkier" cousin to electron, a muon has "-1" electric charge and a spin of 1/2, but over two hundred times more massive. The decay of muons produces at least an electron or a positron, with angular momentum. These charged particles pass on their kinetic energy to molecules they encounter at a biased angle of attack.

The two researchers theorized that the DNA ancestors must have existed in both left- and right-handed conformations with equivalent odds. But the polarized particles can ionize and break apart the right-handed helix slightly more frequently. The breakage of the double-strand structure leads to mutation, and mutation creates more variants. Based on their modeling, having higher odds of mutation help organisms with right-handed DNAs evolve and adapt better to the ever-changing environment of our planet. Over billions of years worth evolution, the B-form DNA becomes the dominant chirality as compared alternative formats.

To better prove that this cosmic rays-induced bias can lead to the emergence of a dominant chirality in DNA (as well other biomolecules), the two scientists also proposed experimental methodologies that can be used in future studies to assess the efficacy of this process.

This latest research is published in the Astrophysical Journal Letters.

Source: Quanta Magazine

About the Author
  • Graduated with a bachelor degree in Pharmaceutical Science and a master degree in neuropharmacology, Daniel is a radiopharmaceutical and radiobiology expert based in Ottawa, Canada. With years of experience in biomedical R&D, Daniel is very into writing. He is constantly fascinated by what's happening in the world of science. He hopes to capture the public's interest and promote scientific literacy with his trending news articles. The recurring topics in his Chemistry & Physics trending news section include alternative energy, material science, theoretical physics, medical imaging, and green chemistry.
You May Also Like
JUN 30, 2020
Space & Astronomy
How it Rain Diamonds on Neptune
JUN 30, 2020
How it Rain Diamonds on Neptune
For some time, scientists have hypothesized that it may be raining diamonds deep inside Neptune and Uranus. They have no ...
JUL 02, 2020
Chemistry & Physics
Carbon Nanolattices: Lighter Than (Atomic) Feathers, Tougher Than Diamonds
JUL 02, 2020
Carbon Nanolattices: Lighter Than (Atomic) Feathers, Tougher Than Diamonds
Carbon is known for its plentiful allotropes, such as the naturally existing graphite and diamond, as well as synthetic ...
AUG 19, 2020
Chemistry & Physics
What about a COVID-19 breathalyzer test?
AUG 19, 2020
What about a COVID-19 breathalyzer test?
New research from a collaboration of researchers share the development of a prototype breathalyzer for detecting COVID-1 ...
AUG 28, 2020
Chemistry & Physics
Interacting Time Crystals and the Future of Time Keeping
AUG 28, 2020
Interacting Time Crystals and the Future of Time Keeping
Time crystals, also known as the space-time crystals, is a newly discovered state of matter that demonstrates distinct s ...
SEP 01, 2020
Chemistry & Physics
New printing process turns paper into a keyboard interface
SEP 01, 2020
New printing process turns paper into a keyboard interface
Imagine taking a piece of paper from your notebook and turning it into a keyboard. Can’t visualize it? Well, now y ...
SEP 10, 2020
Chemistry & Physics
Major advance demonstrated in X-ray crystallographic sample techniques
SEP 10, 2020
Major advance demonstrated in X-ray crystallographic sample techniques
New research published in Nature Communications has corroborated a technique using a microfluidic droplet generator that ...
Loading Comments...