Why is there little diversity and large populations in northern Canada and high diversity with small populations in central and south America?

Northern Canada has a harsh climate and challenging living conditions, which limit agricultural development and economic opportunities, leading to sparse populations. In contrast, Central and South America boast a variety of ecosystems and climates that support diverse flora and fauna, along with more favorable conditions for human settlement and agriculture, resulting in higher population densities. Additionally, historical factors such as colonization and migration patterns have shaped the demographic landscapes of these regions, contributing to the differences in diversity and population distribution.