Not always, usually it’s an evolutionary arms race though. Recent paper I thought was really cool suggests the initial jump from single to multicellular happened because of a snowball Earth which changed the water temperature and therefore viscosity, making larger size equate to more efficient swimming.
Isn’t it almost universal that as long as resources are plentiful, organisms drift toward larger sizes?
Not always, usually it’s an evolutionary arms race though. Recent paper I thought was really cool suggests the initial jump from single to multicellular happened because of a snowball Earth which changed the water temperature and therefore viscosity, making larger size equate to more efficient swimming.
https://www.journals.uchicago.edu/doi/10.1086/716634