Paleontology. Earliest signs of life just oddly shaped crud?
Kerr
Richard A
RA
D001315:Australia; D001419:Bacteria / Q000166:cytology; D000458:Cyanobacteria / Q000166:cytology; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D019369:Life; D010163:Paleontology; D010788:Photosynthesis