[barbs]

> Seem to be forgetting fire. Campfires were surely used by our ancestors, for hundreds of thousands of years, and it is plausible that we evolved to adapt to them.

He does lightly touch on the subject of fire:

> The blue wavelengths of light suppress melatonin production so daylight triggers the body to stop producing it (interestingly red, orange, and yellow wavelengths don’t suppress melatonin production and are the same wavelengths produced by fire)