Nav: Home

USF geologists focus on mineral for clues to beginning of biological life on earth

December 16, 2015

On the early Earth, light came not only from the sun but also from the incessant bombardment of fireball meteorites continually striking the planet. Now, the recent work of University of South Florida (USF) associate professor of geology Matthew Pasek, USF researcher Maheen Gull, and colleagues at Georgia Institute of Technology, has demonstrated that these meteorites may have carried within them an extraterrestrial mineral that, as it corroded in water on Earth, could have provided the essential chemical spark leading to the birth of biological life on the planet.

In previous work, Pasek and colleagues suggested that the ancient meteorites contained the iron-nickel phosphide mineral "schreibersite," and that when schreibersite came into contact with Earth's watery environment a phosphate, a salt, was released that scientists believe could have played a role in the development of "prebiotic" molecules.

In a recent study appearing in Nature Publishing Group's Scientific Reports, the researchers focused on the properties of schreibersite and conducted experiments with the mineral to better understand how - in a chemical reaction with the corrosive effects of water called "phosphorylation" - schreibersite could have provided the phosphate important to the emergence of early biological life.

"Up to ten percent of the Earth's crustal phosphate may have originated from schreibersite, so the mineral was abundant and readily available to engage in early chemical reactions," said Pasek. "This ready and abundant source of reactive phosphorous may have been an important part of the prebiotic Earth and possibly the planet Mars," said Pasek.

What needed to be determined, however, was just how schreibersite reacted chemically with the early Earth's watery environment and what resulted from the chemical reaction.

To test their hypothesis, they built an early Earth model environment, an organic-rich aqueous solution in which schreibersite might react and corrode in a way similar to how events may have unfolded in prebiotic chemistry. The model they constructed provided an opportunity to observe the thermodynamics of phosphorylation reactions of a phosphorus-containing synthetic schreibersite, which they created to be structurally identical to its meteorite counterpart.

"A thorough exploration of the extent of phosphorylation of nucleosides (made of a base and a five carbon sugar) by schreibersite was necessary to evaluate its potential prebiotic importance," explained Gull, a post-doctoral fellow and visiting researcher at USF. "All of our experiments indicated that a basic pH, rather than acidic pH, was required for the production of phosphorylated products. Although phosphorylation can take place using a variety of phosphate minerals in non-aqueous solution, prebiotic oxidation in water is more likely given the dominance of water across the solar system."

The prebiotic reaction they duplicated in the laboratory may have been similar to the reactions that ultimately led to the emergence of metabolic molecules, such as adenosine triphosphate (ATP), which is called the 'molecule of life' because it is central to energy metabolism in all life.

Pasek and Gull also explained that even life today builds from activated nucleotides and that phosphates are still an important part of metabolic processes in biological life, so it is likely that a phosphorylated biomolecule played an important part in creating the prebiotic chemical context from which biological life emerged. Prior work on nucleoside phosphorylation has shown that inorganic phosphate can serve as both a catalyst and a reactant in nucleoside synthesis, they said.

"The reactions we observed in our experiments have shown that the necessary prebiotic molecules were likely present on the early Earth and that the Earth was predisposed to phosphorylated biomolecules," the researchers concluded. "Our results suggest a potential role for meteoritic phosphorus in the development and origin of early life."

The researchers also concluded that the mechanism of phosphorylation was still unknown and actively being investigated. "It is possible that the process occurs in solution or on the surface of the schreibersite," they explained.
-end-


University of South Florida (USF Innovation)

Related Meteorites Articles:

UH research finds evidence of 2 billion years of volcanic activity on Mars
Analysis of a Martian meteorite found in Africa in 2012 has uncovered evidence of at least 2 billion years of volcanic activity on Mars.
Cosmic dust that formed our planets traced to giant stars
Scientists have identified the origin of key stardust grains present in the dust cloud from which the planets in our solar system formed, a study suggests.
Myth busted: No link between gigantic asteroid break-up and rise in biodiversity
Some 470 million years ago, during the middle part of the geological period known as the Ordovician, an asteroid collision took place somewhere between Mars and Jupiter.
Today's rare meteorites were once common
Four-hundred and sixty-six million years ago, there was a giant asteroid collision in outer space, and the debris from that collision has been falling to Earth ever since.
Rare meteorites challenge our understanding of the solar system
Researchers have discovered minerals from 43 meteorites that landed on Earth 470 million years ago.
New evidence on the formation of the solar system
International research involving a Monash University scientist is using new computer models and evidence from meteorites to show that a low-mass supernova triggered the formation of our solar system.
Researchers propose low-mass supernova triggered formation of solar system
A research team led by University of Minnesota School of Physics and Astronomy Professor Yong-Zhong Qian uses new models and evidence from meteorites to show that a low-mass supernova triggered the formation of our solar system.
Meteorites reveal lasting drought on Mars
The lack of liquid water on the surface of Mars today has been demonstrated by new evidence in the form of meteorites on the Red Planet examined by an international team of planetary scientists led by the University of Stirling.
New type of meteorite linked to ancient asteroid collision
An ancient space rock discovered in a Swedish quarry is a type of meteorite never before found on Earth, and likely a remnant of a massive asteroid collision 470 million years ago that sent debris raining to Earth.
SwRI's Bottke named Fellow of Meteoritical Society
Dr. William Bottke, a planetary scientist from Southwest Research Institute, was recently named a Fellow of the Meteoritical Society, recognizing his contributions to meteoritics and related endeavors.

Related Meteorites Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Moving Forward
When the life you've built slips out of your grasp, you're often told it's best to move on. But is that true? Instead of forgetting the past, TED speakers describe how we can move forward with it. Guests include writers Nora McInerny and Suleika Jaouad, and human rights advocate Lindy Lou Isonhood.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...