system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why we have body odour, generally only in the armpit area, and why it would have been useful, in evolutionary terms. Thank you.
gpt
Body odor comes from the bacteria that feed on our sweat and grease (yuck!) not the sweat itself. The smell itself isn't useful in evolutionary terms, but the bacteria are. They are mostly harmless and out-compete bacteria that could be harmful...A symbiotic relationship because the bacteria get free food and we get protected too!