Did life really begin on Earth?

By Casey Frye, CCNN Writer

A meteorite falls from the sky.

As I think about all the different lifeforms on our planet, I often find myself wondering… how did life on Earth begin? Well, according to chemist Steven Benner from Westheimer Institute for Science and Technology, there is evidence to suggest it all began on Mars!

Even though our bodies are complex machines, they are made up of some pretty basic elements. In fact, Harvard biology professor Andrew Knoll – author of Life on a Young Planet: The First Three Billion Years of Life – points out that we are simply “a bag” of simple elements like hydrogen, carbon, and nitrogen. Is it a coincidence, then, that billions of years ago, Earth’s oceans and atmosphere were basically “a bag” of the same elements? Researchers thought not.

In fact, in the 1950s, a graduate student at the University of Chicago, Stanley Miller, conducted a famous experiment to show how life could have started. He mixed some basic elements and gas in a container filled with water, then shocked them using the same kind of electricity that existed on Earth billions of years ago. He left them there for a couple of days, and when he came back, he found the contents of the container combined to make amino acids! If that sounds familiar, it’s because amino acids are the building blocks of proteins, one of the most basic components that make an organism!

Mars planet
Chemists conclude the first molecules necessary for life came from Mars, not Earth.

The experiment excited scientists – heck it even excited me in my biology class – because it was a possible explanation for how life on Earth began. Well, another molecule needed for life is called RNA, which the body needs to build proteins. As chemist Steven Benner explains, a special form of the molecule molybdenum needed is necessary to build RNA, and it needs a lot of oxygen to do so. However, it couldn’t have happened on Earth because the planet  didn’t have enough oxygen for it to happen billions of years ago!

“This form of molybdenum couldn’t have been available on Earth at the time life first began, because three billion years ago the surface of the Earth had very little oxygen, but Mars did,” said Benner. “It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet.”

The dry environment on the Red Planet would have been a perfect environment for molybdenum to build RNA the right way. “The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock,” he stated.

It’s lucky that we ended up on Earth, because mother nature grew into a nourishing source of life! Mars, on the other hand, began to deteriorate and turn into a planet of rocks. Benner said, “If our hypothetical Martian ancestors had remained on Mars, there may not have been a story to tell.” Hear, hear!

Featured image and meteorite image courtesy of NASA. Mars planet image courtesy of J.Gabás Esteban on Flickr.