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Project Progress

Origin and Early Evolution of Photosynthesis (dm)

Work on the origin and early evolution of photosynthesis is carried out by a highly interdisciplinary team of scientists from several different institutions. The overall theme is understanding the origin and early evolution of photosynthesis and its effect on the biosphere. This year four main aspects have been emphasized: (1) molecular evolution analysis of photosynthesis genes from a wide range of organisms, (2) whole genome comparative analyses, (3) field and laboratory studies of photosynthetic organisms in iron-rich environments and (4) the search for phototrophs in non-solar environments around hydrothermal vents (living things that derive their photo-energy from non-solar sources). Each of these projects has seen significant progress, as described below.

Molecular evolution analysis of photosynthesis genes. We have carried out and published sequencing and molecular evolution analysis of photosynthesis genes from all known major groups of photosynthetic organisms.

Whole genome comparative analyses. We developed methods for doing whole genome comparisons. The results, as yet unpublished, strongly support the mosaic nature of bacterial genomes, in which different genes in an organism have distinct evolutionary histories.

Field and laboratory studies of photosynthetic organisms in iron-rich environments. Our field and laboratory studies indicate that some photosynthetic organisms can utilize reduced iron as an electron donor, which may have importance for understanding the origin of the banded iron formations and the rise of oxygen on Earth.

The search for phototrophs in non-solar environments around hydrothermal vents. In July 2000 a team of nine scientists made several dives in the Alvin submersible vehicle to hydrothermal vents of the Endeavor field on the Juan de Fuca Ridge. Samples were collected and are in the process of being analyzed. Analysis of pigments and cultures indicate that chlorophyll-like pigments are ubiquitous in the ocean and that small numbers of photosynthetic organisms are present both near vents and throughout the water column.