Taxonomy is the science of finding, understanding, and naming species of organisms.

I love biology.

Phonetics is a part of linguistics that studies the physical, physiological, and psychological aspects of sounds.

He is a world-renowned scholar.

He is majoring in mineralogy at university.

I am majoring in machine learning.

He is known as an expert in pedagogy.

He is an expert in pedagogy and is deeply involved in the educational activities of children.

He is very excellent in the field of arts and sciences.

That theory is unscientific and has no evidence at all.