'Study of human societies and cultures from the oldest times to the present' is the work of

Anthropology is the holistic study of humanity, focusing on human behavior, biology, societies, and cultures in both the past and the present. It seeks to understand the full sweep of human history from our earliest ancestors to modern-day globalized societies.

• Archaeologists are scientists who study human history and prehistory through the excavation of sites and the analysis of artifacts and other physical remains. While a sub-field of anthropology, it focuses primarily on material evidence.
• Palaeontologists study the history of life on Earth through fossils, which includes plants, animals, and other organisms, not exclusively humans.
• Geologists study the Earth's physical structure, the rocks of which it is composed, and the processes by which they change over time.

Because the definition covers the broad study of societies and cultures across the entire human timeline, it specifically describes the work of anthropologists.