[1][2]  Porter next joined the Department of Organismic and Evolutionary Biology at Harvard University where she studied with Andrew H. Knoll.

From there she joined UCLA in 2002 where she was a National Research Council Post-Doctoral Fellow at the NASA Astrobiology Institute.

[1][3] Porter's research examines the early evolution of eukaryotes during the Proterozoic and Cambrian, 2.5 billion to circa.

Her work has included the description of both early protistan microfossils and Cambrian animals, in particular the small shelly fossils, as well as studies of their preservation, and their utility in telling geologic time or biostratigraphy.

Porter's work on vase-shaped microfossils from the late Tonian Chuar Group of the Grand Canyon, Arizona, showed that these globally widespread protistan fossils are shells of testate amoebae, in particular, members of the Arcellinida, in the Amoebozoa clade.

[4][5][6] Porter and her student Leigh Anne Riedman also described diverse organic-walled microfossils from Chuar Group shales and mudstones some of which included evidence of predation.

[14] Their goal is to reconstruct the redox habitats of  early (>1 billion-year-old) fossil eukaryotes to determine when aerobic metabolism evolved and, possibly, when mitochondria were acquired.