How did life on Earth begin?

How did life on Earth begin? It’s one of the biggest unanswered questions in science. Nicholas Hud and the Center for Chemical Evolution are breaking apart RNA and DNA to determine how the chains of chemicals that make life came together.

DNA is the blueprint for building life, but RNA carries out the DNA’s instructions. RNA helps build the proteins and other materials necessary for life. Their hypothesis is that chains of chemicals called polymers assembled to form RNA and DNA 3.5 billion to 4 billion years ago.

“We’re thinking that on early Earth the molecules that gave rise to the first polymers of life RNA and DNA would have actually started with small molecules interacting with each other and forming very ordered structures,” Hud said.

Hud’s team has been experimenting with chemicals that were present on Earth 3.5 billion years ago. So far, no one in the lab has been able to coax these molecules to self-assemble into RNA. But they’ve gotten something that looks pretty close, Hud says. And that may be our chemical ancestor.

Miles O’Brien has more on the chemical genealogy of life in this special report from the National Science Foundation series “Science Nation.”*

*For the record, the National Science Foundation is also an underwriter of the NewsHour.