UCL Earth Sciences


Hojung Kim

“Nannoplankton, representing a basic step towards the living things from the inorganic stage of being, might show the fundamental feature of evolution, supposedly exclusive of perplexing details.”

PhD project title:

Quantifying rates of evolution in Paleogene coccolithophores.

Hojung Kim
Project description:

The Cretaceous/Paleogene (K/Pg) mass extinction event is the most significant geological event to have affected calcareous nannoplankton, causing over 90% species extinction and followed by the rapid diversification of new groups, which form the core of the modern coccolithophore diversity. As a part of my research, we aim to quantify the rates of evolution in calcareous nannoplankton, immediately following the mass extinction event (Danian). Our initial data come from a recently recovered K/Pg section (IODP Site U1403) drilled on the J-Anomaly Ridge in the northeast Atlantic Ocean during IODP Expedition 342. We focus on a variety of morphometric traits, including coccolith length and width, and cellular traits, including cell geometry (cell size and number of coccoliths per cell). My research will provide information on the evolution rates in the newly evolved lineages, such as (Prinsius, Coccolithus, Cruciplacolithus) and also survivor lineages, such as Cyclagelosphaera and Markalius, as a comparison. These data will provide us with a better insight into the post-mass-extinction recovery of the marine ecosystem.