Between 3.7 to 4.5 billion years ago, life on Earth began. Now, researchers argue meteorites splashed down and leaked essential elements into warm ponds.
Scientists at McMaster University and the Max Planck Institute in Germany report wet and dry cycles bonded basic molecular chemicals int he pounds producing a nutrient-rich solution, which in turn created self-replicating RNA molecules that formed the first genetic code of life on Earth.
The researchers reached this conclusion after researching geology, chemistry, biology, astrophysics and other fields of science. While the “warm little ponds” theory is not new, researchers have proven its plausibility with evidence-based calculations.
The study’s lead authors, Ben K.D. Pearce and Ralph Pudritz say evidence suggests that life began when the Earth was still being formed, which continents emerging from the ocean and meteorites hammering down into the planet.
“No one’s actually run the calculation before,” says Pearce. “This is a pretty big beginning. It’s pretty exciting.”
“Because there are so many inputs from so many different fields, it’s kind of amazing that it all hangs together,” Pudritz says. “Each step led very naturally to the next. To have them all lead to a clear picture, in the end, is saying there’s something right about this.”
The study was published today in the Proceedings of the National Academy of Science.
“In order to understand the origin of life, we need to understand Earth as it was billions of years ago. As our study shows, astronomy provides a vital part of the answer. The details of how our solar system formed have direct consequences for the origin of life on Earth,” says Thomas Henning explained.
Researchers say the combination of wet and dry conditions allowed for RNA to be produced and form chemical bonds.
“That’s the Holy Grail of experimental origins-of-life chemistry,” says Pearce.
The basic form of life, RNA, would eventually give rise to DNA, the blueprint of higher forms of life. But, it will take time for this to take place. Essentially, the world only existed with RNA-based life forms until DNA was created.
“DNA is too complex to have been the first aspect of life to emerge,” Pudritz says. “It had to start with something else, and that is RNA.”