The origin of nucleobases and amino acids, the building blocks of DNA, and by extension, life, has been one of the most enduring mysteries in scientific history. While various organic molecules -- the precursors to life -- have been found in deep space, the question of how they became complex enough to constitute life has never been solved.
Researchers from three Japanese universities -- the Tohoku University, the National Institute for Materials Science and the Hiroshima University -- led by Tohoku researcher Yoshihiro Furukawa, conducted tests that simulated meteorite impacts on ancient oceans. Upon recovering the chemical products after the impacts, the researchers discovered nucleobases and amino acids that had been formed from inorganic compounds, according to a press release Tuesday.
The results of the research were published in the journal Earth and Planetary Science Letters.
All genetic information in living beings is stored in DNA sequences comprised of nucleobases. However, scientists believe that the odds of these structures being formed naturally on Earth are very low.
In 2009, the same team conducted another experiment that involved simulated meteorite impacts and found evidence for the formation of the simplest amino acid called glycine. However, in the new experiments, the researchers found evidence of even more complex structures, including two kinds of nucleobases and nine kinds of protein-forming amino acids.
Previous research from NASA suggests that these complex organic structures may have been formed on asteroids, which then landed on the planet -- a theory known as panspermia.
However, the results from Furukawa’s team suggest a new route for how genetic molecules may have first formed on the planet.