Final answer:
Friedrich Miescher was the first person to isolate what we now call nucleic acids in the 1860s, a fundamental discovery in genetics.
Step-by-step explanation:
The material that came to be known as nucleic acids was first isolated by Friedrich Miescher in the 1860s. Miescher was a physician with a keen interest in biochemistry, and his groundbreaking work laid the foundation for our modern understanding of DNA and RNA. He discovered these phosphate-rich chemicals within the nuclei of white blood cells, which he termed 'nuclein'. This pioneering discovery eventually led to the identification of DNA and RNA, fundamental molecules in genetics.