Later he studied at the Harvard University and reached Ph.D. Degree in the 1977 with his dissertation work "Studies in Archean and Early Proterozoic Paleontology”. Afterwards, he worked as a teacher at Oberlin College for the five years.

In the 1982 he comes back to the Harvard by working as a professor. Since then he has done a lot of work in paleontology. The one of the major his contributions is a discovering of microfossil records of early life in Siberia, China, South and middle regions of Africa as well as in Australia.

Being a paleontologist, he also was interested in bio-mineralization, paleobotany as well as in plankton evolution. He also had some interests in mass extinction. Andrew Knoll was one of the first scientists, who made a hypothesis that more than 250 million years ago in the end-Permian mass extinction the rapid build-up of carbon dioxide played the main role.

Beside working as a professor in Harward, Andrew is a member of a science team for mission to Mars by NASA. He is a member of the United States National Academy of Sciences, the American Academy of Arts and Sciences as well as of the American Academy of Microbiology.

Currently, he is working as a Professor of Natural History and a Professor of Earth and Planetary Sciences at famous Harvard University. Additionally, he is known by working with such departments like Organismic and Evolutionary Biology and Earth and Planetary Sciences.

In the 1987 he was awarded with both Walcott Medal and Charles Schuchert Award for his useful contributions to understanding the Precambrian life. In the 1996 he was awarded an honorary doctorate from Uppsala University in Sweden. He reached a lot of awards in the 2000s. He got a Paleontological Society Medal in the 2005. Two years later, Andrew was honored with Wollaston Medal for his major contribution in Geology.

In addition to his work in the Harvard, he also is an author of numerous scientific works like “Life on a Young Planet: The First Three Billion Years of Evolution on Earth” and “The Evolution of Primary Producers in the Sea”, which was published in the 2004 and 2007. In the 2012 along with his colleagues, he published other work “Fundamentals of Geobiology”. The next year appeared his book, which was titled “Biology: How Life Works”.

He is married, but there is no any information about his wife. He likes to keep his personal life to himself and stays away from the media as far as possible. He earns a good salary from his job, but his net worth is unknown.