Species differentiation in fossil organisms, usually based on morphologic characteristics, may, from a biologic perspective, be artificial. Molecular paleontology, which utilizes innovations in biochemistry, molecular biology, and genetics, provides an independent means of obtaining genetic information from organic matrix extracted from fossil shells. Sequencing of shell proteins may, if successful, enable reconstructions of certain ancient DNA-sequences and the original alignment and folding of protein molecules which together with polysaccharides constitute the main part of the organic matrix in calcareous fossils. The studies are extended back to the Late Neogene to compare phylogenetic relationships inferred from biochemical data with those based on standard phylogeny.
Amino acids occur mainly in L-conformation in proteins.
Applications in geochronology and molecular taxonomy.