Invasive species can have a major impact on the natural environment.

He is deeply studying the teachings of Prajnaparamita.

He started a new business, but as the proverb 'the road to happiness is strewn with setbacks' suggests, he is facing many difficulties.

I am majoring in microbiology at university.

Astrobiology is a very interesting field of study.

I am majoring in microbiology at university.

He is an expert in paleontology.

He is an expert in aerobiology, engaged in the study of microorganisms in the atmosphere.

He is very interested in paleontology.

I am majoring in Biochemistry at university.