1. Chloe Arwood, Ryan Jun and Yue Wen
Oxygenation and Evolution
Chloe Arwood, Ryan Jun and Yue Wen

2. Introduction Early evolution is closely linked to Earth's oxygenation
Fossil records reveal important events in evolutionary history
Concentrations of certain elements in sedimentary rock are indicative of oxygenation levels
The featured study uses this method with the element Mo (Dahl et al. 2010)
Ediacaran( Ma)
1st clearly multicellular life forms
Cambrian( Ma)
“Cambrian Explosion”
Devonian( Ma)
Deversification of vascular plants

3. Data
δ98Mo levels were highest during two episodes (highlighted in blue and green on the graph)
~550 Ma: levels rose from 1.1‰ to 1.6‰
~ Ma: rose to 2.0‰

4. Discussion
The episodes of highest Mo values correlate with time periods associated with significant evolution
The first episode corresponds with the “Cambrian Explosion” which introduced bilaterian animals
The second episode corresponds with the Devonian period, which produced diversification of vascular plants and large predatory fish

5. Conclusion
“Increased Oxygenation is correlated with events of significant evolution.”

6. Literature Cited
Dahla, Tais W. "Devonian Rise in Atmospheric Oxygen Correlated to the." N.p., 17 Aug Web.
Freeman, Scott, and Healy Hamilton. “27.” Biological Science. Upper Saddle River, NJ: Pearson Prentice Hall,
Knoll, Andrew, Karl Niklas, Patricia Gensel, and Bruce Tiffney Paleobiology, Vol. 10, No. 1 (Winter 1984): pp