One day, either out of idle curiosity, or out of necessity, or for both reasons at once, but the human species will have to leave planet Earth and begin a journey to the stars. There are many factors to consider before embarking on this historic journey.
For example, how quickly can we get to the planet we want to colonize, or how many people will need to be put on a spaceship for this opportunity to actually succeed?
And while previous research on this topic, one of which was, for example, in 2002, argued that it would take only 150 people to start a new human race, new research by John Moore of the University of Florida claims that the number of people needed to settle another planet will have to be at least 10,000, and best of all - 40,000.
So why are there so many people? The first thing to draw our attention to is the fact that even the closest star system to us, Proxima Centauri, is located more than four light-years from Earth. The current level of technology development will take us thousands of years to get there.
This also means that we will need to build such a spaceship, on board which several generations will be born and die, who will not even see the planet that humanity wants to colonize, let alone the planet where they come from. 150 people may indeed be able to cope with this task, but an excessively low genetic diversity will greatly increase the risk of various genetic diseases and abnormalities, which will jeopardize the entire colonization mission.
In his study, Moore points out that a higher number of people, at least 10,000, could increase the overall level of viable diversity in the traveler's gene pool.
The second reason why space colonization will require many people is the risk of various disasters. There will definitely be diseases, man-made disasters, maybe aliens will come for new slaves, in general, we must take into account each of these risks, because each of them can significantly reduce the population of space colonists. The more people go to colonize, the less disastrous the consequences of their loss will be.
How did Moore arrive at these numbers? As part of his research, he used a computer model invented by William Gardner-O'Kearney, an archaeologist from Portland, Oregon, USA. The algorithm of this computer model allows for a selection of various events that may occur during space travel.
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Having determined the initial population size and scheduling it, for example, for an interval of 300 years (30 generations), the algorithm runs each number (size) 10 times and displays the average result of the residual number of people for one or another simulation model of the development of events.
It should be noted that, first of all, this calculation model allows us to consider the consequences of those unexpected events that may occur in space. Now, the results show that with an initial 40,000 colonists, the genetic diversity would be 100 percent. However, even with only 10,000 people, this genetic diversity remains at an acceptable level.
The model shows that in the event of events that can affect population size, both of these numbers can keep enough colonists to maintain genetic diversity. If the initial number of colonists is less than 10,000, then this will significantly reduce the chances of people for survival and development on another planet.