Here's an article citing research published this year that disputes the idea that our large brain was directly a result of access to extra protein from hunting meat:
"They concluded that the evidence for increased carnivory in our ancestors is merely an effect of increased sampling of the archaeological record at certain time intervals starting around two million years ago, meaning that there is no strong relationship between eating more meat and the evolution of larger brains in our ancestors."
The way we used arxiv worked well in physics, though this is 15 years ago now so might have changed since.
arxiv was about distribution. It didn't replace peer review - articles were still submitted to journals and published there too.
If an article was posted to arxiv and not a journal, the odds of a citation went down massively. And the journal it was submitted to was a factor in whether or not we read it. When articles were eventually published, most authors also updated the preprint with the post peer review version.
Basically it meant that
(1) it was easy to keep up to date with what everyone was working on, and pick up interesting new stuff
(2) most citations, post 80s, you saw in whatever paper you were reading, you could look up on arxiv and be reading it in seconds.
"They concluded that the evidence for increased carnivory in our ancestors is merely an effect of increased sampling of the archaeological record at certain time intervals starting around two million years ago, meaning that there is no strong relationship between eating more meat and the evolution of larger brains in our ancestors."
https://www.smithsonianmag.com/smithsonian-institution/fourt...