Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Earliest life or rare dirt?

07.03.2002


Life forms: Schopf thinks these marks are fossils of ancient bacteria.
© Nature


Dishing the dirt: Brasier’s team reckons geological processes made the squiggles.
© Nature


Gloves are coming off in ancient bacteria bust-up.

A claim to have found evidence of the oldest living things on Earth is being fiercely contested. The argument looks set to run and run, and no one may win, but it may lead to a better understanding of the origins of life on our planet.

The debate is academic, but its implications are not. The ’fossil bacteria’ in question are around 3.5 billion years old. That’s roughly one billion years older than the only confirmed fossil bacteria.



This would mean that complex biochemistry - including photosynthesis - originated around one billion years after the Earth formed. Photosynthesis released oxygen into the atmosphere, which has supported the majority of life ever since.

Dark microscopic squiggles in rocks called ’Apex chert’ from Western Australia, are the fossils of various species of cyanobacteria, according to William Schopf of the University of California, Los Angeles1.

A team led by Martin Brasier at the University of Oxford, UK, believes that Schopf’s ’fossils’, although unusual, are simply tiny clumps of impurities in the rock2.

Fellow researchers are loath to be named for fear of "exacerbating what looks like becoming an acrimonious debate", according to one. They are nonetheless following the details closely. "This is a fascinating debate," says another.

Most agree that the age of the Apex chert rocks may preclude either side ever being proved right.

Technical point

Schopf’s team studied the structure and chemical composition of the squiggles with a technique called laser-Raman imagery. The group argues that the marks are made up of carbon molecules, which are the decay products of living bacterial cells. "They are tiny little fossils," says Schopf.

Brasier’s team repeated some of Schopf’s analyses recently and disagrees. "Schopf’s hypothesis is deeply flawed," Brasier says.

Brasier’s team agrees that the marks’ chemical composition appears biological in origin. But the group thinks that they actually arose through unusual geological processes around ancient hydrothermal vents, where hot volcanic gases rise to the surface.

What’s more, the group says, the squiggles look nothing like other ancient microbes. "The shapes are far too complicated to be bacteria," says Brasier, who feels Schopf should drop his claim.

Brasier’s group asserts that biological-seeming molecules can result from reactions between the carbon dioxide and monoxide released by hot, metal-rich hydrothermal vents. These molecules could then have been sculpted into bacteria-esque filaments as the hot rocks they were born in cooled.

If this was the case, argues Schopf, such material would be found everywhere. So far it hasn’t been. "The facts are going to win and I’ve got the data," he says.

Win-win?

The one thing both parties agree on is that only time will tell. Schopf is continuing to analyse his putative fossils. A nanoscale examination of their ’cell membranes’ will, he claims, prove beyond doubt that the Apex chert does contain the oldest known remains of life on Earth.

Brasier and his team are now investigating the kind of chemical reactions that they believe produced the squiggles. The researchers suspect the reactions could themselves have created complex molecules such as amino acids and be the source of life on Earth. "Schopf may have stumbled on a site that may explain how life got started," says Brasier.

References

  1. Schopf, J. W., Kudryavtsev, A. B., Agresti, D. G., Wdowiak, T. J. & Czaja, A. D. Laser-Raman imagery of Earth’s earliest fossils. Nature, 416, 73 - 76, (2002).
  2. Brasier, D. M. et al. Questioning the evidence for Earth’s oldest fossils. Nature, 416, 76 - 81, (2002).

TOM CLARKE | © Nature News Service

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>