Genetic Diversity

[Puddle-Jumper]

i never watched bsg so i don't know about that.

as for sgu: i guess that there would be, seeming as about 100 people on destiny would create 50 families or so, then the kids (who aren't related to eachother) would have more kids, who will have kids and ect. so with each generation the amount of families increase, meaning that there are more distant relatives. and by a 1000 years there was a population of a million people.

BSG isn't really a good source for information on genetics.

The short answer is no its not enough, though the crew did come from various ethnic backgrounds so theres an outside chance that they could selectively mate for a few generations to give the maximum potential..

Or its science fiction and FTL and what not isn't possible either..

[Perelandra]

Finally, a topic on which I can speak intelligently!

I'm a population geneticist, this is what I'm actually teaching this semester.

As several people have pointed out, one of the questions is the relative proportions of males and females. Biologists use a term called "effective population size" to measure how much genetic diversity a population will likely maintain over time.

For a population that has Nm males and Nf females (where Nm and Nf are integers representing the actual number of males and females), the effective population size is:

Ne = 4*Nm*Nf/(Nm + Nf)

So let's say that there are 20 women and 40 men aboard the Destiny.

The effective population size is only: 4(20)(40)/(20+40) = 3200/60 = 53.33

This is less than the actual population size of 60, because each new person receives 1/2 of his/her genes from a female and half from a male - the smaller number of females forms its own "bottleneck".

This assumes everyone is equally likely to reproduce - the effective population size will be smaller if there are some individuals that reproduce more than others.

But let's take an effective population size of about 50 as our estimate. Is that big enough to found a human population for the long term?

It is if the founding population is genetically diverse enough, so that it is unlikely that any two people are carrying the same recessive deleterious mutations. We all have some recessive deleterious mutations - most of the time, the person with whom we reproduce has different ones, and then our offspring don't get 2 copies of a deleterious gene at the same locus (gene). That's why many (but not all) organisms avoid close inbreeding.

The current theory of human population expansion out of Africa poses multiple small groups founding population in Europe and Asia. It is certainly likely that some of these groups had less than 100 breeding individuals. Could they have persisted without later influxes of people and genes from other groups?

I think the answer is "maybe". Certainly, we have seen populations of other mammals survive bottlenecks much more severe than 50 breeding individuals.

Wow,very interesting-thank you!

[Icarus]

This makes no sense. So how are humans into their billions then?

[Trinary]

This makes no sense. So how are humans into their billions then?

Pornography. Lolz.

[jelgate]

This makes no sense. So how are humans into their billions then?

Genetic mutations

[SaberBlade]

This makes no sense. So how are humans into their billions then?

10,000 years ago, Ancients started to have children with native humans (no idea how that works as I can't really see an Ancient picking up a primitive Human at a singles bar). They would have added fresh and superior DNA into the mix and started the Neolithic Revolution.

[carmencatalina]

This makes no sense. So how are humans into their billions then?

All you have to do to understand this is to understand the beauty of the exponential function!

Humans are currently undergoing exponential growth (it is all a bit terrifying actually). For much of human evolution, we probably numbered in the thousands - tens of thousands (that's what my anthropology friends tell me, anyway. Then, after beginning of agricultural, we started really increasing in numbers (with a few minor set backs - see Black Plague).

Here's a nice graph:



So how does this exponential growth work, anyway?

Here's the equation:

N(t) = N(0)*exp(r*t)

N(t) = population size at time t
N(0) = initial population size
t = amount of time (in generations)
r = rate of growth

Let's say we are at 10,000 humans, and the growth rate is 0.014 (that's the estimate of our current growth rate, by the way), then, in 500 generations (about 1,000 years), you get, approximately:

1.1 x 10^7 humans

That's a huge increase. It doesn't take long to reach a billion (10^9). In reality, the human population grew at rates lower than 0.014 for a long time, only recently did we get to 0.014.

But anyway - exponential growth. Scary, but that's how we roll.

[erotavlas]

So does this all mean that Eli got busy with all the females on Destiny? Including Wray?

Too bad Rush and Telfod missed out lol ,
Although that brings up an interesting question, was it good or bad that the civilization is missing out on Rush's DNA?

[Ben 'Teal'c would WIN!!' Noble]

All you have to do to understand this is to understand the beauty of the exponential function!

Humans are currently undergoing exponential growth (it is all a bit terrifying actually). For much of human evolution, we probably numbered in the thousands - tens of thousands (that's what my anthropology friends tell me, anyway. Then, after beginning of agricultural, we started really increasing in numbers (with a few minor set backs - see Black Plague).

Here's a nice graph:

[IMG]http://wps.prenhall.com/wps/media/objects/489/501216/CDA48_2.jpg[MG]

So how does this exponential growth work, anyway?

Here's the equation:

N(t) = N(0)*exp(r*t)

N(t) = population size at time t
N(0) = initial population size
t = amount of time (in generations)
r = rate of growth

Let's say we are at 10,000 humans, and the growth rate is 0.014 (that's the estimate of our current growth rate, by the way), then, in 500 generations (about 1,000 years), you get, approximately:

1.1 x 10^7 humans

That's a huge increase. It doesn't take long to reach a billion (10^9). In reality, the human population grew at rates lower than 0.014 for a long time, only recently did we get to 0.014.

But anyway - exponential growth. Scary, but that's how we roll.

What do you make of what this guy says?

http://en.wikipedia.org/wiki/Steve_Olson_(writer)

[Nth Chevron]

A fresh and unique adaptation of something that can never be proven in our lifetime.

N.C

[Girlbot]

So does this all mean that Eli got busy with all the females on Destiny? Including Wray?

Too bad Rush and Telfod missed out lol ,
Although that brings up an interesting question, was it good or bad that the civilization is missing out on Rush's DNA?

Good, no one needs to pass along a psychopath.

[thekillman]

is it possible the Novans have advanced sufficiently to enact genetic alteration (safely) to cancel out certain mutations?


for that matter, wouldn't it be wise, far far wiser in fact to actively enforce IVF to ensure the offspring has the most optimum genes?

[D Toccs]

is it possible the Novans have advanced sufficiently to enact genetic alteration (safely) to cancel out certain mutations?

There's no doubt that given a population of millions and the level of technology they seem to possess, that they would be capable of that now.

The issue at hand is whether the gene pool would be strong enough to make it that far in the first place.

[thekillman]

doesn't that basically make this entire question based upon the genetic strength of the people we have ?

[D Toccs]

doesn't that basically make this entire question based upon the genetic strength of the people we have ?

No, the entire question is based on whether or not there are enough people to create a stable gene pool.

The answer seems to be . . . maybe.