Came here to say that, and it's easily disproven as well.  Considering our ancestors came out of Africa (or Australia depending on the evidence you use), both very hot and very dry continents that are a far cry from "tropical beaches".  Blubber would be fatal in those kinds of climates where you need larger surface area to body mass ratios (hence being taller and leaner) in order to lose heat and keep cool. This is why desert animals are either very small and/or they have large thin surface areas like big ears (elephants and fennec foxes for example) to lose heat from their blood as it circulates. One would also not need blubber in the tropics, at all.  Animals that have blubber typically live in very cold regions such as the Arctic and Antarctic. Really it's not difficult to debunk fat theories with basic logic. 😂