avoidance of inbreeding in small huntr gatherer tribes

For reasons I’ve discussed many times (for example, “Cultural impedance, demographic growth, effective population size”), the effective population size of humans does not mean that the actual number of people in the ancestral human population was very small. And a starting population of 40,000 would be even better, in case a large percentage of the population died during during the journey.Ī number as large as 40,000 people would enable the mission to approximate the effective population size of the entire human population of earth before 100,000 years ago or so. According to Portland State University anthropologist Cameron Smith, any such starship would have to carry a minimum of 10,000 people to secure the success of the endeavor.

And a new study sets the bar much higher than Moore's 150 people. This brings up the question of how many people you need to send on a hypothetical interstellar mission to sustain sufficient genetic diversity. Moore concluded that the social structure necessary to prevent inbreeding was essentially that of clans or extended tribes of hunter-gatherers – strong kin avoidance rules to prevent inbreeding and a population size of 150-300 people.Ī new paper by Cameron Smith focuses instead on the worst case scenarios, concluding that the “safe” population size would be much higher: Entire generations of people would be born, live, and die before the ship reached its destination. The article starts by noting the work of anthropologist John Moore on the question. Too few people, and the colonists will rapidly lose genetic diversity by genetic drift.

The basic problem is that a multigenerational star voyage requires the trekkers to mate and reproduce many times while maintaining a limited population size. Popular Mechanics asks, “How Many People Does It Take to Colonize Another Star System?”.

Avoidance of inbreeding in small huntr gatherer tribes