Which of these would be evidence that cyanobacteria evolved the ability to perform photosynthesis on earth over 2 billion years ago? a) a decrease in glucose in cellular fossils more recent than 2 billion years ago b) an increase in oxygen gas in the atmosphere and oceans starting 2 billion years ago c) an increase in carbon dioxide levels in the atmosphere and soils from 2 billion years ago d) the presence of eukaryotic cellular structures trapped in ice from earlier than 2 billion years ago