Biology 9th Edition by Eldra Solomon,Linda Berg ,Diana Martin

تمرين 4

ANALYZING DATA. Evidence for the oldest cyanobacterial fossils (stromatolites)dates to about 2 billion years, but molecular evidence inferred from lipids in ancient rocks puts the date for living cyanobacteria and eukaryotes at 2.7 billion years. Develop two opposing hypotheses to explain the discrepancy between the dates.