Final answer:
Migration of people is a likely effect in the regions with the darkest shading, as economic, environmental, and demographic pressures drive individuals to seek better living conditions and job opportunities, leading to rural-to-urban shifts and changes in population composition.
Step-by-step explanation:
If the regions with the darkest shading represent areas with pressures due to economic development, climate change, or human population increase, a likely effect if the trend continues would be Migration of people from these regions. This migration could occur due to the changes in the carrying capacity of these regions, affecting human living conditions and economic opportunities. Faced with these challenges, people often migrate in search of better living conditions and job prospects, which can lead to a shift from rural to urban areas—especially in regions transitioning to stage 3 of the demographic transition model where there is an increased rate of rural-to-urban migration driven by industrialization and job opportunities in urban areas.
Factors such as climate change could also force migration, as certain species decline while others move in, altering the sustainability of local ecosystems. This could impact food supply and living conditions, prompting human migration. As people look for culturally or linguistically compatible countries, migration patterns can shift, which means that the regions with the darkest shading may experience significant demographic changes in terms of population composition.