Prior to her work, it was unclear whether choanoflagellates or fungi were the closest outgroup to multicellular animals (also called "metazoans").
King's comparative genomics work in collaboration with Sean Carroll helped to elucidate the evolutionary "tree of life."
More recent work by King demonstrates that molecules thought to underpin the transition to multicellarity also exist in choanoflagellates and therefore were present in the single-celled and colonial ancestors of animals.
In addition, King found that choanoflagellates possess genes that animal cells use to "talk" or signal to one another, such as Receptor tyrosine kinase.
from Indiana University Bloomington in 1992, in the lab of Thom Kaufman, working on the genetic workhorse, the fruitfly, also known as Drosophila melanogaster.