What does biogeography study?

Biogeography is the branch of biology that specifically focuses on the distribution of species and ecosystems in geographic space and through geological time. It seeks to understand how and why certain species are found in specific locations, looking at factors such as climate, geography, and evolutionary history. By studying these distributions, biogeographers can trace the historical events, environmental factors, and ecological interactions that have influenced where species live and how they interact with each other and their environments.

This study is crucial for understanding biodiversity, ecosystem dynamics, and the effects of climate change on species distribution. It encompasses both the current geopolitical boundaries that define habitats and the historical factors that have shaped the movement and evolution of organisms across the planet through time.

While other fields within biology, such as systematics and ecology, also examine important concepts, they do not primarily focus on the geographic distribution aspect that characterizes biogeography. Hence, the correct option highlights that biogeography is fundamentally concerned with the "distribution of species and ecosystems."