Why does invading a planet need 40,000 people?

A new study by Portland State University in Oregon, USA, suggests that humanity, if it wants to invade an extraterrestrial planet, requires a really large amount of manpower besides a spacecraft. about 20,000 to 40,000 people.

According to an explanation by anthropologist Cameron Smith of Portland State University, a large population is needed to conquer a new planet because that amount will create genetic diversity and demographics . The best opportunity for survival in the process of moving to space is both long and far away.

Previously, researchers had suggested that just a few hundred people could be enough to settle on an alien planet. But according to Smith, this issue needs reconsideration.'I want to review this issue. Now we have a better understanding of population genetics from genes , 'Smith said.

In addition to the need for a large spacecraft, the number of people brought to conquer the planet also requires tens of thousands of people to ensure long-term quality of human resources.

In a study published in Acta Astronautica, Smith said, a interstellar trip lasts about 150 years. This is also the time that coincides with the forecast of researchers at the organization that tracks the stars of Icarus Instellar.

Based on this time, Smith created a computer model of the combination of dynamic population genetics with numbers from 14,000 to 40,000 people. The results show that the safe number falls to about 40,000 people, including about 23,000 people including men and women of childbearing age.

Smith admits, this number can cause a "big surprise" , but he says it has a great meaning in the journey to conquer a planet of mankind. For reasons that number of employees will maintain better health for the population for 5 generations in a row, because it avoids the inbreeding phenomenon increases , reduces genetic diversity and changes demographics through time due to small population. At the same time a large population also enhances survival to prevent extinction.

To reinforce the conclusion, Smith summarizes the data of other vertebrate populations in the world.'Almost no natural population of vertebrates is reduced to less than 5,000 to 7,000 individuals. There are many genetic reasons in this regard. Because when they are below this threshold, they can survive but will go into a disaster of extinction , 'Smith said.

In addition to the plan to bring such a huge population, Smith also noted the plan to send frozen sperm and eggs in the journey to conquer the new planet. However, Smith did not uphold this option because according to him, it could not be as good as the people who had life experiences on earth.