Complex sentence: In the early 20th century, the Polish cultural anthropologist Maria Czaplicka divided Siberia into Paleo-Siberians, representing the most ancient stock, and Neo-Siberians.
Split into simpler sentences: In the early 20th century, the Polish cultural anthropologist Maria. A. Czaplicka divided Siberia into Paleo-Siberians, representing the most ancient stock, and Neo-Siberians.