The utility of nondestructive laser Raman for testing the biogenicity of microfossil-like structures in ancient rocks is promising, yet results from deposits like the ∼3.46 Ga Apex chert remain contentious. The essence of the debate is that associated microstructures, which are not purported to be microfossils, also contain reduced carbon that displays Raman D- and G-band peaks similar to those...

Circular graphite discs, among abundant irregular graphite particles, have been extracted from ArcheanPaleoproterozoic amphibolite grade metamorphic rocks in the Wutaishan area of North China. Raman spectroscopic analysis indicates that these graphite discs experienced maximum metamorphic temperature of 513 ± 50 °C. The discs bear morphological features related to metamorphism, but they are als...

Introduction: For over a decade, the oldest evidence for life on this planet has been microfossils in the 3.5 Ga Apex Chert in Western Australia [1]. Recently, the biogenicity of these carbon-rich structures has been called into question through reanalysis of the local geology and reinterpretation of the original thin sections. Although initially described as a stratiform, bedded chert of silic...

Homochirality of the biomolecules (D-sugars of DNA and RNA and L-amino acids of proteins) is a fundamental property of all life on Earth. Abiotic mechanisms yield racemic mixtures (D/L=1) of chiral molecules and after the death of an organism, the enantiopure chiral biomolecules slowly racemize. Several independent investigators have now established that the amino acids present in CI1 and CM2 c...

Large (>100 microm), profusely ornamented microfossils comprise a distinctive paleontological component of sedimentary rocks deposited during the Ediacaran Period (635-542 million years ago). Smaller spinose fossils in Paleozoic rocks have commonly been interpreted as algal cysts or phycomata, but the Ediacaran populations differ from modern algal analogs in size, shape, ultrastructure, and int...

Oat (Avena sativa L.) traditionally has been a major crop for feed and forage in Turkey. Theobjective of this research was to study hay yield and quality of oat genotypes harvested at thelate milk stage. One hundred oat varieties of worldwide origin were compared in fieldexperiments in Samsun (northern Turkey) over two growing seasons (2007-2008 and 2008-2009).Significant differences between th...

(1) For every macro instruction I and for every integer location a holds card(if a = 0 then I; Goto(insloc(0)) else (StopSCMFSA)) = card I +6. (2) For every macro instruction I and for every integer location a holds card(if a > 0 then I; Goto(insloc(0)) else (StopSCMFSA)) = card I +6. Let a be an integer location and let I be a macro instruction. The functor while a = 0 do I yields a macro inst...

Evidence of Archean life: Stromatolites and microfossils J. William Schopf a,∗, Anatoliy B. Kudryavtsev b, Andrew D. Czaja c, Abhishek B. Tripathi c a Department of Earth and Space Sciences, Center for the Study of Evolution and the Origin of Life (Institute of Geophysics and Planetary Physics), Molecular Biology Institute, and NASA Astrobiology Institute, University of California, Los Angeles,...