Answer:
The population in South America tends to be heavily concentrated along the coastlines while the deeper we go in the interior the less population there is.
Step-by-step explanation:
South America is a continent that has a very uneven distribution of its population. The vast majority of the population lives along the coastline or close to the coastline. The interior of the continent is sparsely populated, so much so that some parts of the interior are among the least populated areas in the world.
The reasons for why this is the case are geography, climate, and distance from the other larger cities. The interior of the continent is dominated by the Amazon rainforest, huge wetlands like the Pantanal, and very high and steep mountains. The Amazon and Pantanal are simply not suitable for human existence on a large scale because the temperatures are high, rainfall intense, hunidity very high, flooding of enormous areas and they are extremely difficult to have proper infrastructure built through them. The very high and steep mountains have very harsh conditions, with a lack of soil, strong winds, unstable and unpredictable weather conditions.
The people of course tend to choose the places that offer the best living conditions, and in South America, those places are along the coastline and near it. The climate is milder, there is access to the ocean, infrastructure is easy to construct and maintain, trade and transportation are also very easy.