system
Given the following post, respond as if you're commenting on Reddit:
human
How large a colony must be in order to be genetically diverse?

Operating on a example - how many people would be required for a colony to avoid inbreeding?

Or to rephrase - how many generations must pass so offspring from the same n-grandfather could mate without consequences?
gpt
The homo-sapien population is theorized to have dropped from around 21,000 to around 618 breeding individuals around 195,000 years ago. Due to the Long glacial stage known as Marine Isotope Stage 6 (MIS6) that lasted until roughly 123,000 years ago. This explains the lack of genetic diversity in modern humans. 

They managed to produce 7.2 billion of us, with only 618 individuals.