This journal provides immediate access to some articles. Volume 361(1474); October 29, 2006 Research Articles Self-assembly processes in the prebiotic environment PMCID: PMC1664680 Implications of a 3.472–3.333Gyr-old subaerial microbial mat from the Barberton greenstone belt, South Africa for the UV environmental conditions on the early Earth PMCID: PMC1664690 | ||