This DNA—the oldest genomic evidence recovered to date—illuminates the evolutionary history of woolly mammoths and Columbian mammoths. Advances in ancient DNA extraction and sequencing methods eventually brought to light genomes of creatures from deeper time, including cave bears and Neandertals. One tooth, discovered in deposits thought to be around 700,000 years old, looked like that of an early woolly mammoth, Mammuthus primigenius. They got hundreds of millions of base pairs constituting around 25 to 30 percent of the genome of the second oldest mammoth. The oldest human DNA comes from remains dated to 430,000 years ago.