Guest post with author Susan Kelley - Minimal Viable Population

I'm still enjoying some family vacation time, but I have a special treat for you. Please welcome the wonderful Susan Kelley to my blog!

MVP: Minimal Viable Population

I’m thrilled to be here on Christine’s blog and take it over for a day. Let’s talk some genetics science stuff.

Survivors of the Apocalypse, my three book dystopian romance series, is set three hundred years in the future. A virus has nearly wiped out mankind. Inside a doomed city are thousands of people, surviving by keeping their sterile city completely closed to the outside. But there are people outside the doom who survived the pandemic. They’re living rugged, frontier lives, but they have plenty of resources. The thing they don’t have is a large population.

This forces the frontiersman to reach out to the city, hoping to recruit people so they can maintain a MVP, minimal viable population. What is that number for humans? There are many examples in science of species being brought back from extinction, some with as few as one breeding couple. But what about humans?

There are plenty of opinions on that, ranging from 50 couples to 10,000 or even 50,000. The TV show Salvation put that number at 160, which is a number sometimes quoted in the scientific community. The population would have to careful to prevent inbreeding. Why is inbreeding bad? After all, many of the old noble houses in Europe, and let’s not forget the Tsars of Russian, who married relatives for generations. And that most famous of fictional inbreeding stories, Game of Thrones, showcases how common though not always accepted marrying a close relative was in medieval times. Here’s an interesting debate on those numbers.

Now for the bad:

Any birth defects that are in the family line become more likely to appear.

Genetic issues that are recessive are more likely to come up if related people have offspring.

Successive generations of close inbreeding will decrease the diversity more and increase the rate of bad mutations.

Siblings or parents and kids (super disgusting) marrying are the worst. They share 50% of their DNA. First cousins share 12.5% and until rather recently, wasn’t considered that bad of a thing. Before people became more mobile, most people were born, lived, and died within less than a ten-mile radius. They didn’t have many options. It was also a way to keep wealth within the family. Once people moved around more and women had more say in their futures, first cousin marriage started to be frowned upon. In some parts of the USA, it is against the law though the US is the only western country that has such a prohibition. However, there are groups of people in the world who still practice it. Read more interesting facts about cousins marrying.

On the fictional series like Game of Thrones, we see the Targaryens have many family members who suffer from some mental issues. But what we really want to know is if Jon and Daenerys should have children, being aunt and nephew? Most of today’s societies would consider that an incestual relationship. But then again, it’s in Westeros.

But back to my series, the outsiders are smart enough to understand they need a larger gene pool. But can the city people survive the outside air where the virus still lurks? Can the outsider people possibly convince the city folks that a match with a rugged frontiersman is the best thing for mankind?

The last book in the series, Exile’s Savage Lady, is now available along with the first two books at all major eBook retailers. Robin Linden was saved was saved by the outsiders when he was exiled from the city by a corrupt government. Now he’s determined to return to the city and bring the cure to the starving, oppressed population. Kerry Gibbs was raised with her brothers on the wild frontier and isn’t afraid of anything. Until he realizes she might lose the strong, quiet big man back to the city he feels responsible for saving. Her only choice is to sneak into the city with Robin and make sure he doesn’t get himself killed. Robin is willing to sacrifice himself to save those unfortunates, but Kerry is going to do everything she can to make sure he survives. The city is a dangerous place and neither of them may make it out alive.

Amazon Link

Susan Kelley has been writing for more than ten years and has nineteen published romances. She resides in a large country home in central Pennsylvania where she has raised six children alongside her husband of many years. Deer, turkeys, hawks, and other wildlife cavort outside the window of her office where she writes fulltime. Find her:

On her blog, Susan Says

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What do you think about marrying cousins? How close is too close? How many people would you put on a ship to populate a space colony?