Aupporting cells of the nervous system are collectively called:

Supporting cells of the nervous system are collectively called neuroglia.

They are called neuroglia or glial cells.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.