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 Cells migrate collectively by intermittent bursts of activity
30.09.2016 | Aalto University

nachricht The structure of the BinAB toxin revealed: one small step for Man, a major problem for mosquitoes!
30.09.2016 | CNRS (Délégation Paris Michel-Ange)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>