He is a world-renowned biologist.

He is traveling around the world as an ecologist.

He is a world-famous archaeologist.

He is a renowned criminologist who has contributed to many crime analyses.

The seismologist is studying earthquake prediction and disaster prevention.

He is a world-renowned zoologist.

My father is an ichthyologist and has a deep knowledge about marine life.

He always likes to be pedantic, explaining things down to the smallest detail.

He is a renowned anthropologist, traveling around the world to study human cultures.

He is a renowned economist who has written many important papers.