+ not having enough food for everyone
+ how many people migrate
+ birth/death rates
+ how much water there is
+ how much nutrients/minerals are available
+ how much trees/oxygen is available
The answer is tunicates. Tunicates are commonly known as sea squirts and are in the Chordata phylum, even though they don't have a back bone. Which is really weird. But they just got put into the same category as humans. This is because they have a notocord and a back bone when they are larvae. But they lose all these when they become adults.
