Never Mind Fingerprints, Here Are Genome-prints

Items that leave a mark as fossils are usually bones or shells, blogs Olivia Judson, but genomes can also leave a trail. The bigger the genome of an organism, she says, the more DNA is packed into the cell, affecting the cell's volume. If the same cell type is compared across species, then the difference in size reflects the difference in genome size, she says. Though genome size says nothing about complexity, it still can provide a bit of information about metabolism and lifestyle of the extinct organism, says Judson.