Is the origin of life on Earth the result of a long chemical process? Or does it come from space? It would seem that the second proposition is more probable. Japanese researchers have just discovered for the first time the four main constituent elements of DNA on a meteorite. As a reminder, our DNA is made up of four nucleotides: adenine, thymine, guanine and cytosine. 50 years ago, adenine and guanine had already been observed on a meteorite, but not the other two.
This is now done as scientists from Hokkaido University in Japan have discovered the four nucleotides on three carbon-rich meteorites. These three meteorites had been discovered in Australia, in the State of Oklahoma in the United States, as well as in British Columbia in Canada.
This discovery suggests that the building blocks of life might have arrived on Earth through extraterrestrial objects. This theory has existed since ancient times and is called panspermia. In our case, this means that organisms might have arrived on our planet thanks to meteorites ejected from their home planets because of an impact on them. “This study demonstrates that a variety of nucleotides from meteorites may have served as the building blocks of DNA and RNA on early Earth,” explains Yasuhiro Oba, the researcher behind this study, in an interview for Vice.
