http://www.nature.com/nsu/030804/030804-4.html

 

Tiny geological features thought by some to be the fossil remains of primitive bacteria are probably nothing more than fossilized lumps of lifeless protein, say two US scientists.

 

The structures, dubbed nanobacteria, are typically 50-200 millionths of a millimetre across. They have been found in some sedimentary rocks, and even in the martian meteorite ALH84001, leading to claims of evidence for life on Mars. Debate has raged for eight years over whether or not they are the fossilized remains of single-celled organisms ten times smaller than today's.

 

Now Jürgen Schieber, of Indiana University in Bloomington, and Howard Arnott, of the University of Texas at Arlington, report that spherical balls of protein about 40-120 nanometres across are produced when organic material decays in an environment like that in which sedimentary rocks form1.

 

That would certainly fit the conclusions of a panel of scientists convened in 1998 by the US National Academy of Sciences to study the nanobacteria controversy. The committee decided that organisms smaller than about 200 nanometres in diameter would not be viable. That did not end the discussion, however. Some researchers claim to have grown nanobacteria in the laboratory.

hrm

test