The bacteria family tree may be facing some changes due to the recent work of an evolutionary biologist at Washington University in St. Louis. And that may change our understanding of when bacteria and oxygen first appeared on earth. Carrine Blank, Ph.D. , assistant professor of earth and planetary sciences in Arts & Sciences, has found that the currently accepted dates for the appearance of oxygen-producing bacteria and sulfur-producing bacteria on the early earth are not correct. She believes that these bacteria appeared on earth much later than is now believed. “It sets up a new framework of new hypotheses to be tested,” she says of the new findings. Blank’s findings appear in the February 2004 issue of Geobiology.
