Can a couple create the world after a disaster of extinction?

Sci-fi films often present a situation where a disaster strikes and the Earth has only one (or a few) surviving couples. Then they gradually rebuild their lives and make the world population grow again. Is that really possible?

After the disaster of destruction, the world was rebuilt thanks to a couple?

According to geneticist Professor Nolan Kane at Colorado Boulder University: That is possible, but surviving couples will have to be very, very . busy and have to be extremely lucky.

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People are always afraid of natural disasters such as tsunamis, meteorite collisions, climate change, . will suddenly come to the death of most humans.

This may not be too big a threat to other organisms because as long as only a few individuals exist, the species is maintained and has the opportunity to regenerate into a population. Professor Kane gives an example of dandelion, a model of proliferation from a few original seeds. " A dandelion seed can produce thousands of other seeds that carry identical genetic code and spread with exponentiality. But unfortunately people are not dandelions, we need one of the opposite sex and more than 9 months to reproduce. "

In a situation where human populations are in serious decline, Professor Kane said that would lead to a serious problem he called "founding effect ". When a small group is isolated from a large population, the common and often harmful genetic traits will become common.

The reason is that the small number of " founders" makes the diversity of genetic combinations limited. Currently, we have seen isolated, typical populations such as the Amish in Pennsylvania who have a very high rate of polydactyly (polydactyly - malformations with extra fingers and toes). Similarly, on the island of Pingelap isolated on the Pacific Ocean , up to 5% of the population is color blind.

Therefore, if there is only one single man who survives but suffers from Celiac disease (digestive disease that damages the small intestine and hinders the absorption of nutrients from food), is it not just him? It is possible to absorb gluten but certainly, the whole "humanity" that has been formed is likewise. And Celiac is just a good example of many genetic diseases (such as sickle cell anemia) that can destroy the lives of new residents.

Jeff Wall, associate professor of epidemiology and biological statistics at the University of California, said: "There is a reason why the law prohibits inbreeding marriage. Every time we create a child, the mechanism Genetics has a chance of getting a defect and this rate will increase significantly if poorly diverse individuals mate with each other. luckily in the "genetic lottery" game, and as you know, the lottery hit rate has never been higher. Moreover, a sudden change in the environment can make 2 people die. Before the child is born Even when they avoid the dangers from the outside environment, the combination of internal genes can create a child. "In the absence of medical care, it may be the last individual of humanity."

Because of human genetic mechanisms, many scientists suspect that if a real disaster strikes, then humans will not be able to survive through several generations. However, all of these are just hypotheses and be optimistic, people always find a way to defend and prevent catastrophic destruction before it happens. And yes, if Earth's apocalypse comes, it will be the same as when it first started.