Sentences with phrase «kept oxygen concentrations»
By tunneling through the sea floor, these creatures altered our planet's chemistry and kept oxygen concentrations at just the right level to allow animals and other complex life to evolve.
http://www.sciencemag.org/
By tunneling through the sea floor, scientists say, these creatures kept oxygen concentrations at just the right level to allow animals and other complex life to evolve.
Not exact matches
Analyzing sensor data and field measurements, Cohen and his students have found new clues for the algal abundance, such as declining concentrations of dissolved oxygen and the role of snails in keeping springs clear.