The Naked Scientists
Toggle navigation
Login
Register
Podcasts
The Naked Scientists
eLife
Naked Genetics
Naked Astronomy
In short
Naked Neuroscience
Ask! The Naked Scientists
Question of the Week
Archive
Video
SUBSCRIBE to our Podcasts
Articles
Science News
Features
Interviews
Answers to Science Questions
Get Naked
Donate
Do an Experiment
Science Forum
Ask a Question
About
Meet the team
Our Sponsors
Site Map
Contact us
User menu
Login
Register
Search
Home
Help
Search
Tags
Member Map
Recent Topics
Login
Register
Naked Science Forum
General Discussion & Feedback
Radio Show & Podcast Feedback
QotW - 15.08.11 - How many people are needed to avoid inbreeding?
« previous
next »
Print
Pages: [
1
]
Go Down
QotW - 15.08.11 - How many people are needed to avoid inbreeding?
1 Replies
2213 Views
0 Tags
0 Members and 1 Guest are viewing this topic.
thedoc
(OP)
Forum Admin
Moderator
Hero Member
510
Activity:
0%
Thanked: 21 times
QotW - 15.08.11 - How many people are needed to avoid inbreeding?
«
on:
12/08/2015 11:15:14 »
How many people are needed to avoid inbreeding in a population?
Asked by Louise
Find out more on our podcast page
[chapter podcast=1001133 track=15.08.11/Naked_Scientists_Show_15.08.11_1003984.mp3]
...or Listen to the Answer[/chapter] or
[download as MP3]
«
Last Edit: 12/08/2015 11:15:14 by _system
»
Logged
thedoc
(OP)
Forum Admin
Moderator
Hero Member
510
Activity:
0%
Thanked: 21 times
QotW - 15.08.11 - How many people are needed to avoid inbreeding?
«
Reply #1 on:
12/08/2015 11:15:14 »
We answered this question on the show...
Connie
- Well, Louise. That question all sounds a little Adam and Eve. And it’s also something the naked scientists have been wondering. You see, we recently bought a desert island in the Pacific, and we want to avoid any sticky situations in the future. So, how many people do we need to start with to keep our island healthy? When I asked you on Facebook and Twitter, Glenn Fisher thought that only one was a safe bet, whilst Jay Michael Antovics II thought that it might depend on what definition we use. Maybe Professor Mike Weale, a statistical geneticist from King’s College London can help us.
Mike
- So, inbreeding means different things to different people. So, there no one single answer to this question. Everyone is related to their partner somehow, it’s just a question of how far one needs to go back in time before a common ancestor is found.
Connie
- Oh wow! So wait a minute! Does that mean I’m technically related to my boyfriend?
Mike
- Technically, yes! I mean, to stop all relatedness between all mating partners, you would need, in fact, an infinite number of people.
Connie
- Okay. I see. But our island isn’t going to be infinitely big, and more importantly, I’m not sure I can stomach the idea of being related to my boyfriend. And that must also mean that absolutely everybody is inbred, which just doesn’t feel quite right. Surely, there’s another way?
Mike
- Well. Yes. There is. To a population geneticist, the definition of inbreeding is simply a situation where mating partners are more closely related than what’s expected by chance. So, using this definition all one needs to do to avoid inbreeding is to select mating partners purely by chance, as though you were in the lottery. And then, the population can be as small as you want. Well, you need to have at least two. But in a small population, even one that was enjoying some hedonistic version of the national lottery, mating partners will unavoidably tend to be more closely related to each other.
Connie
- And I suppose that can’t be good for the future?
Mike
- Yep. In the short term, this increases the chances of people suffering from certain types of genetic diseases, diseases such as cystic fibrosis or Tay-Sachs disease, for example. This is because these diseases are caused by inheriting a bad genetic variant both from one’s mother and from one’s father. And the chances of them both having the same bad genetic variant are increased if they are closely related to each other.
Connie
- Okay. So, where does that leave us then?
Mike
- Ultimately, there’s no magic population threshold that will make this problem go away. But a study in 2002 suggests that a population of 160 onboard a so called generation spaceship travelling to the stars should be able to keep itself genetically healthy. So, this would be a reasonable guideline for your desert island. In fact, real human populations on islands in the Pacific have survived population crashes down to as few as 20 people, but I wouldn’t recommend this as a way to keep your desert island either healthy or happy.
Connie
- Well. There we have it. It all depends on your definition. I think to be on the safe side, I’m going with at least a few hundred. Who wants to come?
«
Last Edit: 12/08/2015 11:15:14 by _system
»
Logged
Print
Pages: [
1
]
Go Up
« previous
next »
Tags:
There was an error while thanking
Thanking...