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Starsaber
April 18th, 2011, 07:51 PM
With 80-however many people there were on Destiny, did they really have enough people to create a stable gene pool that would last 2000 years? I remember in BSG, Baltar said that the Colonial fleet (with like 45000 people) wouldn't last nearly that long before they started having problems, so the question just kind of popped into my head. Any thoughts?

themeatcleaver
April 18th, 2011, 07:54 PM
with a little bit of thought, i'd have to imagine that they'd be alright but yeah... it seems a little low to me. then again, they didn't have much of a choice so hey, like Scott said, its a crap shoot!

blueray
April 18th, 2011, 08:06 PM
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.

jelgate
April 18th, 2011, 08:10 PM
I don't think it would that much of an issue given the diversity of the original population

D Toccs
April 18th, 2011, 08:30 PM
The minimum requirements for a stable gene pool (at least one that could expand to millions and last for 2000 years) are around 2000 people, ideally with a ratio of 2 or 3 women for every man.


i guess that there would be, seeming as about 100 people on destiny would create 50 families or so.

100 people would only be able to create 50 families if the ratio was 1:1 women to men. However the Destiny crew has been shown to consist of more men then women.

This was all discussed in the pre-airing thread in more detail. But I feel the only way that the Destiny crew could hope to diversify their gene pool would be for all of the women to have multiple children each to multiple partners, in effect becoming baby making machines for the rest of their lives.
Even then, genetic degradation would be a major factor well before 2000 years.

Realistically it's just not feasible, but then again neither was the Serrakin/Human crossbreeding on Hebridan.
It's fiction, just go with it :)

SG-17
April 18th, 2011, 08:40 PM
I remember that someone did the math in the speculation thread and it came out to be that 20 breeding pairs were sufficient to prevent serious genetic defects.

D Toccs
April 18th, 2011, 08:52 PM
I remember that someone did the math in the speculation thread and it came out to be that 20 breeding pairs were sufficient to prevent serious genetic defects.

Each one of those pairs would have to have at least 3 or 4 children. Each one of those children would have to be paired up with someone in an "arranged marriage" in order to keep maximum diversity and avoid the same families crossbreeding more then needed.

In short, the society for at least the first few generations would be centered around the gene pool.
You would be assigned a sexual partner (the only one you'd be allowed to have) and your duty would be to produce as many children with that partner as possible. Your children upon coming of age would then be assigned their own partners and so on.

Given human nature, such a structured society would be difficult to maintain.

escyos
April 18th, 2011, 08:52 PM
Theres only like 60 people aboard. Most of them are male so a fiar portion of genetic material is diverse enough to stave off genetic degradation for at least 3-4 generations.

If it is meticulously planned out and people are only allowed to breed with certain people then it is possible until they have at least 500 people.

tomaso88
April 18th, 2011, 09:53 PM
If their are millions of people at some stage wouldnt they have to be inbreeds and is the chances of that many people even happening even realistic at all I mean seriously their aren't that many people on destiny to start a civilization like some one said it was mentioned on battlestar galactica that 40thousand would be hard enough to start one and on sgu we are talking about like 80 max people. I thought the idea was cool but very very very unrealistic

GoodSmeagol
April 18th, 2011, 09:54 PM
You underestimate the power of the genome.
Having your third cousins children is 100% within acceptable genetic norms.

Populations can spring forth from much fewer specimens then you can think.
The Galapagos Islands have a diverse population of tortoises.
No more then 10 females are the parents to every single one of the 10+ species of tortoises you can find on the different islands. They have been there for millions of years.
Human genome is a little more complicated and would require a slightly more diversified genetic profile. Once you reach thousands tho, genetic diversity would not be an issue ever again.

^500 people would be like 4th or 5th generation, clearing that 3rd cousin stuff too^

Interesting episode!

BadOnion
April 18th, 2011, 09:56 PM
But don't all you good Christians believe we started with just two people?

tomaso88
April 18th, 2011, 09:58 PM
But don't all you good Christians believe we started with just two people?

actually you are wrong about that the catholic church has acknowledged that a lot of the stories such as the creation stories were teaches and not fact.

wolpertinger
April 18th, 2011, 10:12 PM
You underestimate the power of the genome.
Having your third cousins children is 100% within acceptable genetic norms.

Populations can spring forth from much fewer specimens then you can think.
The Galapagos Islands have a diverse population of tortoises.
Interesting episode!

It is more a problem of humans in particular: we are genetically rather uniform due to some bottlenecking roughly 70k years ago (it is often being said that any two humans are genetically more similar to each other than two chimps from the same forest)

That being said, the founding population here also included some LA members so there should be enough genetic diversity

darkthunder84
April 18th, 2011, 10:19 PM
Alot of people believe in the stories written in the Bible (new and old testament). According to the Bible, we're all descendant from Adam and Eve (2 people). If 2 people are enough to eventually create a civilization of BILLIONS, why can't a group of 60-80 people form a civilization of MILLIONS (which is less) ?

Browncoat1984
April 18th, 2011, 10:20 PM
My problem is that 2000 years did not make an advanced society like that quite believable. Maybe they went back farther, like 20,000 years or something.

BadOnion
April 18th, 2011, 10:22 PM
Why? We went that far in much less than 2000 years, and without the head start in knowledge these people began with. If anything they should be quite a bit more advanced than us.

knowles2
April 19th, 2011, 12:46 AM
I agree they should be more advance than us.

An from what I have read on here, it seem the first Destiny crew made saw to record all there knowledge as best as they could, Kinos were use. The Nova technology would have evolve pretty fast on the planet.

Especially if they were organise and maintain there focus on building a stable civilisation for there children.

Even Wray did her duty.
I fine it quite believable that us Humans have that kind of focus and effort and willingness.


Why 80 people may be a tad to low, I fine it believable that with the right dedication and forsight and knowledge and lots of family planning they would be able to keep there genetic pool stable.

An also a bit of luck of having no major genetic defects amongst the crew would also help keep the gene pool stable. An diversity of the gene is also important having a good mixed of difference races and having the Lucian alliance there to would have helped.

Mr Evil 37
April 19th, 2011, 12:59 AM
Point of interest: comparing the scientific realism of one sci-fi show with another is never a very good idea.

If every couple had three or four children, then the population would quadruple in roughly half a decade, and would continue to grow exponentially since they had setting up a colony as their goal. I don't think there would have been any problems at all.

Plus, with the way Scott gets through women he could probably sustain the colony all by himself. :P

Gatefan1976
April 19th, 2011, 02:22 AM
While I cannot remember the actual Ep, TNG had a similar issue where the "backward" Irish folk became one with a Technologically advanced human colony that were using cloning to sustain thier population. In that instance there were some 160 individuals but Dr Pulaski said as long as each female had children by 3-5 different males for 3? generations they would create enough genetic diversity to rebuild both societies.

Now I don't know the math behind it, or even if it was accurate but the Destiny crew seems to have roughly 20 odd females onboard, so *assuming* the math used in Trek is correct, I think each woman would have to have more like 10+ kids to different fathers to re-seed a viable population base. :eek:

KEK
April 19th, 2011, 02:26 AM
Someone did the maths in the other thread. It would work if it was control, but some of the men would have to wait a generation to get theirs, so to speak...

Trinary
April 19th, 2011, 03:22 AM
Consider this. Every continent on Earth has similar ancient story about human ancestors coming from people on a ship after the big flood. When is that? Presumably, it was between 4 to 6 thousand years ago. Now the human population was around 7 billions. How many people on that ship survived after the big flood? Probably less than a dozen. Even the animals they brought over was just a couple of each.

For a 2000 year to reach a few millions is very possible. With language and knowledge that already developed, it will not very hard to reach millions. It's not something you could controlled once a civilization started to replicates, Lol! We're a replicator too... :D

thekillman
April 19th, 2011, 03:47 AM
Each one of those children would have to be paired up with someone in an "arranged marriage" in order to keep maximum diversity and avoid the same families crossbreeding more then needed.

no.


there is no need for forced breeding. even with incest, people tend to fall in love with those who have the most different genes. a friend of mine studies medicine and he told me.

morrismike
April 19th, 2011, 04:07 AM
As long as the society had rules to keep blood relatives (closer than uncles/aunts/2nd cousins/etc) from pairing it would be fine. I'm afraid after 2000 years any trace of race would be gone though. From a practical standpoint they'd want to encourage those couples with healthy (good eyesight and stuff like that) children to start pumping out kids.

senilegreen
April 19th, 2011, 04:12 AM
Consider this. Every continent on Earth has similar ancient story about human ancestors coming from people on a ship after the big flood.

False.

senilegreen
April 19th, 2011, 04:18 AM
I've watched every episode of SGU and some more than once. From what I remember of this season (the post LA invasion), looking at the 17 episodes, and then remembering how many different people there are - minus the loss of those few LA (leaving a few onboard)... I get that there would be damn few people in the founding population.

How many fertile females are there? I don't think it even adds up to 30. And many of them are not especially young.

It's not genetic diversity that is a problem, but the lack of bodies to do work.

morrismike
April 19th, 2011, 04:27 AM
I've watched every episode of SGU and some more than once. From what I remember of this season (the post LA invasion), looking at the 17 episodes, and then remembering how many different people there are - minus the loss of those few LA (leaving a few onboard)... I get that there would be damn few people in the founding population.

How many fertile females are there? I don't think it even adds up to 30. And many of them are not especially young.

It's not genetic diversity that is a problem, but the lack of bodies to do work.

If the first wave of women pump out 10 kids per with several men it wouldn't be an issue. Star Trek did a show on this very topic. Ironically enough on the startrek episode, an extended liberty would have injected (quite literally) a whole lot of Enterprise genetic material into the cloner gene pool.

MechaThor
April 19th, 2011, 04:33 AM
I don't think genes would be a problem, its not like anyone on the Destiny is currently related so no interbreeding from the start. Plus 80+ seems like enough, surly all these remote tribes and island populations have similar size groups? Also is it not true that most Europeans share a common ancestor anyways? Formed from a small group of people that came from Africa through Turkey or something?

aquaman
April 19th, 2011, 04:57 AM
It would take 'genetically' 300 people, 150 men and 150 women with each woman having between 3 to 5 children by different men for 10 generations to have a viable gene pool that is not highly prone to genetic flaws

sholva1
April 19th, 2011, 05:27 AM
yes, each woman would have to have at least 3 kids by a different father

Egle01
April 19th, 2011, 05:37 AM
I've watched every episode of SGU and some more than once. From what I remember of this season (the post LA invasion), looking at the 17 episodes, and then remembering how many different people there are - minus the loss of those few LA (leaving a few onboard)... I get that there would be damn few people in the founding population.Not that it helps much, but those LA members who died in "The Hunt" were still alive in "Twin Destinies".

Mr Evil 37
April 19th, 2011, 05:40 AM
It would take 'genetically' 300 people, 150 men and 150 women with each woman having between 3 to 5 children by different men for 10 generations to have a viable gene pool that is not highly prone to genetic flaws

And you know this how...?

Girlbot
April 19th, 2011, 05:47 AM
This is assuming that all the females would be capable of reproducing the number of offspring needed, then there would be the mortality rate among the population due to the circumstances they were living under, the lack of medical facilities, etc. You can't just do math of figures alone, without factoring in other probablilites, that might decrease the gene pool IMO

spaceship
April 19th, 2011, 06:52 AM
With 80-however many people there were on Destiny, did they really have enough people to create a stable gene pool that would last 2000 years? I remember in BSG, Baltar said that the Colonial fleet (with like 45000 people) wouldn't last nearly that long before they started having problems, so the question just kind of popped into my head. Any thoughts?

The problem in BSG wasn't genetic diversity. It was a cultural thing. People weren't having enough children. The birth rate was too low compared to the death rate. That is why they started encouraging child bearing.

Perelandra
April 19th, 2011, 06:55 AM
I don't think it would that much of an issue given the diversity of the original population

I don't know about genetics, but I agree with this.

ETA: I didn't find a large civilization stemming from 80 or so original people to be a stretch at all.
And there is already genetic diversity on the Destiny, no one is related, so no first cousins, marrying, ect.
(What I found more of a stretch was people still speaking the same English that the founders, spoke, but a minor quibble.)

Quetzocoetl
April 19th, 2011, 07:20 AM
I don't know about genetics, but I agree with this.

ETA: I didn't find a large civilization stemming from 80 or so original people to be a stretch at all.
And there is already genetic diversity on the Destiny, no one is related, so no first cousins, marrying, ect.
(What I found more of a stretch was people still speaking the same English that the founders, spoke, but a minor quibble.)

Agreed.
Though...I figured the whole English thing was because they had easy access to spoken English via the Kinos.

Trinary
April 19th, 2011, 07:33 AM
Ancestor with Kino. This alone could explode into similar flying devices and vehicles. It's strange what they had only Kino's memory storage technology with them after 2000 years?

The colony should at least has cubical camp site that they could carry through gate travel. Off course, could be loaded on top of flying SUV. An equivalent to small convertible puddle jumper.

Perelandra
April 19th, 2011, 07:43 AM
Agreed.
Though...I figured the whole English thing was because they had easy access to spoken English via the Kinos.

yes, I think you're right, now that I think about it.

knowles2
April 19th, 2011, 08:21 AM
Ancestor with Kino. This alone could explode into similar flying devices and vehicles. It's strange what they had only Kino's memory storage technology with them after 2000 years?

The colony should at least has cubical camp site that they could carry through gate travel. Off course, could be loaded on top of flying SUV. An equivalent to small convertible puddle jumper.

May be they did. We do not know how long they spent on the planet before they cut off.

An it might be that they cannibalise there most advance pieces of technology to keep the power generators and radio communication equipment going.

zainea13
April 19th, 2011, 09:04 AM
It would be possible, but the show made it seem like it was 'whoever can have kids with whoever' ... But it would have to be strict. One man for instance might have to seed 3 generations. So yes like a 80 year old man have sex with a 16 or 18 year old woman for the sake of genetic diversity.

Once they get to everyone being a second cousin or beyond, genetic disease should be limited if not eradicated.

Geral
April 19th, 2011, 09:23 AM
You underestimate the power of the genome.
Having your third cousins children is 100% within acceptable genetic norms.

Populations can spring forth from much fewer specimens then you can think.
The Galapagos Islands have a diverse population of tortoises.
No more then 10 females are the parents to every single one of the 10+ species of tortoises you can find on the different islands. They have been there for millions of years.
Human genome is a little more complicated and would require a slightly more diversified genetic profile. Once you reach thousands tho, genetic diversity would not be an issue ever again.

^500 people would be like 4th or 5th generation, clearing that 3rd cousin stuff too^

Interesting episode!

Exactly. I think people underestimate 'stable gene pools'. They could breed with first, second, third cousins and as long as they keep some knowledge of genetic abnormalities I see no reason why they couldn't do it. With 60-100 or so people, I think it would be plenty of diversity to do it (though they'd still suffer from our genetic ailments). The problem occurs with far less than that, a dozen or so, that dangerous conditions become more statistically likely.

carmencatalina
April 19th, 2011, 10:10 AM
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.

knowles2
April 19th, 2011, 11:47 AM
Rhinos are one species that have been bought back from very low numbers, some species as low as fifty I believe. An they are accepting to do the same with the last 7 remaining Northern White Rhino.
But some mammals have got a natural resistance to inbreeding, cats for instant.
carmencatalina may be you should give the SGU scenario as an assignment for your students to answer whether the population on destiny is viable or not.

g.o.d
April 19th, 2011, 11:53 AM
actually you don't need more than 60 people to start a civilisation. Of course, there must be more females than males, but it's fine to begin with less than 60 (56 to be more accurate). Some of descendants would be "slower" but you don't high numbers.

carmencatalina
April 19th, 2011, 12:14 PM
carmencatalina may be you should give the SGU scenario as an assignment for your students to answer whether the population on destiny is viable or not.

I would need to make some assumption on the frequency of deleterious mutations in the initial Destiny population, and on how genetically related they are. If you throw in that information (that we don't have), you could do some fun calculations.

Excellent idea for a homework problem!

Trinary
April 19th, 2011, 12:19 PM
I believe in a single gene could mutated into different races if they spread into different geographical area in a planet or the variation how they live their life. The surrounding area most likely contribute how they evolve and adapt to the place they live in. It will resulting into a different skin color, shape of the eyes, their height and various other changes.

For example, a number of a fat human race are now increasing around the world based on what and how they eat such as similar food menu and frequency. They're basically a new human race that evolve drive by the food they had consumed. They used to be abnormal, but now it was seem common a new born overweight baby taken these new evolved gene.

Starsaber
April 19th, 2011, 12:28 PM
...
{Good stuff}
...


Thanks for the very informed answer. I'm a software engineer, not a biologist or statistician, so it was mostly idle speculation on my part.

Another thing. Do the close matches for kidney transplants play into the genetic diversity much, or is that something different. Wouldn't have an impact on the first generation, since Brody and both potential donors were male, but I'm curious.

Oh, and time to update your signature. Down to 3 new episodes left :(

carmencatalina
April 19th, 2011, 12:30 PM
I believe in a single gene could mutated into different races if they spread into different geographical area in a planet or the variation how they live their life. The surrounding area most likely contribute how they evolve and adapt to the place they live in. It will resulting into a different skin color, shape of the eyes, their height and various other changes.

For example, a number of a fat human race are now increasing around the world based on what and how they eat such as similar food menu and frequency. They're basically a new human race that evolve drive by the food they had consumed. They used to be abnormal, but now it was seem common a new born overweight baby taken these new evolved gene.

Most of the traits you've mentioned here (skin color, weight, shape of eyes, height) are most definitely NOT caused by a single gene. They are all examples of what we call "quantitative" or "complex" traits - that are due to the actions of multiple genes AND environmental components.

While you can definitely have mutations of single genes that affect these traits, the variation you see in our human population in these traits is NOT due to the action of a single gene.

Starsaber
April 19th, 2011, 12:30 PM
...
{Good stuff}
...


Thanks for the very informed answer. I'm a software engineer, not a biologist or statistician, so it was mostly idle speculation on my part.

Another thing. Do the close matches for kidney transplants play into the genetic diversity much, or is that something different. Wouldn't have an impact on the first generation, since Brody and both potential donors were male, but I'm curious.

Oh, and time to update your signature. Down to 3 new episodes left :(

carmencatalina
April 19th, 2011, 12:32 PM
Oh, and time to update your signature. Down to 3 new episodes left :(

Thanks! Updated (sadly).

Trinary
April 19th, 2011, 12:40 PM
I noticed there was 2 different height of human race in overall. Most of the south origins were shorter while the north origins were taller.

What make of it? Atmospherics pressure? Gravity? or Magnetic poles configurations?

wingsabre
April 19th, 2011, 12:40 PM
Smaller tribes of people in other cultures have lasted fairly long with a small gene pool. Plus, most of the military personals have been selectively picked in a way that does eliminate certain genetic defects, so in terms of genetic problems, they may have little. If the south can survive for a greater part of 2 centuries, I'm not surprised the Destiny crew can survive longer.

carmencatalina
April 19th, 2011, 01:02 PM
I noticed there was 2 different height of human race in overall. Most of the south origins were shorter while the north origins were taller.

What make of it? Atmospherics pressure? Gravity? or Magnetic poles configurations?

I don't think this is correct, there are certainly groups of humans that are overall shorter or taller, but there isn't a clear longitudinal gradient. You can look at the Inuit, who certainly live far towards the north pole, and see a people that are not very tall.

garhkal
April 19th, 2011, 04:34 PM
Each one of those pairs would have to have at least 3 or 4 children. Each one of those children would have to be paired up with someone in an "arranged marriage" in order to keep maximum diversity and avoid the same families crossbreeding more then needed.

In short, the society for at least the first few generations would be centered around the gene pool.
You would be assigned a sexual partner (the only one you'd be allowed to have) and your duty would be to produce as many children with that partner as possible. Your children upon coming of age would then be assigned their own partners and so on.

Given human nature, such a structured society would be difficult to maintain.

Which to me, might not be too far off what might have happened.. Especially since most were US and therefore were raise with the history of the pilgrms, who in some parts did just that.




My problem is that 2000 years did not make an advanced society like that quite believable. Maybe they went back farther, like 20,000 years or something.




They were raised with the knowledge the crew had.. which is pretty important. The only 2 limiters would be what resources they had, and what was passed on.


If the first wave of women pump out 10 kids per with several men it wouldn't be an issue. Star Trek did a show on this very topic. Ironically enough on the startrek episode, an extended liberty would have injected (quite literally) a whole lot of Enterprise genetic material into the cloner gene pool.

There was also a film on the Scifi channel, iirc where a virus (man made) was released by baddies trying to steal it, and the only way to stay safe against it was be in the polar cap. So the US antartic site was good.. Each woman there had to do a 'lottery' for the men to see whom would be their birther for that 'season'...


May be they did. We do not know how long they spent on the planet before they cut off.

An it might be that they cannibalise there most advance pieces of technology to keep the power generators and radio communication equipment going.

Plus maybe they didn't have the natural resources to do some of that..

D Toccs
April 19th, 2011, 04:45 PM
Another problem, is that the group that split away to become the Futurans did so in The original Destiny crew's lifetimes. I can't imagine after such a schism that there would be much interbreeding between the two rival groups.

So while there is a chance that the original group could form a stable population. That original group was split in half very early on, effectively halving the gene pool for both factions.

I just can't see how it could work given that situation.

garhkal
April 19th, 2011, 06:49 PM
Well, if i have 2 kids a year, every 3 yrs, i can have a lot of kids in 40 years..

BadOnion
April 19th, 2011, 11:10 PM
Another problem, is that the group that split away to become the Futurans did so in The original Destiny crew's lifetimes. I can't imagine after such a schism that there would be much interbreeding between the two rival groups.

So while there is a chance that the original group could form a stable population. That original group was split in half very early on, effectively halving the gene pool for both factions.

I just can't see how it could work given that situation.

From Young's apparent age it was 30 or 40 years. Long enough to have two more generations of people.

D Toccs
April 19th, 2011, 11:29 PM
From Young's apparent age it was 30 or 40 years. Long enough to have two more generations of people.

It would still reduce the gene pool of each side down to smaller then the original crew.

thekillman
April 19th, 2011, 11:53 PM
i believe the Futurans only really founded a nation much, much later.


it isn't really clear and that kino footage doesn't actually show them leaving, just considering leaving

D Toccs
April 20th, 2011, 01:03 AM
i believe the Futurans only really founded a nation much, much later.

We know that Brody named Futura so the original crew must have still been alive.

knowles2
April 20th, 2011, 01:53 AM
We still do not know how bad relations were between the two groups. I guesting this will be explored sooner or latter or may be that was a season 3 episode.
For all we know they may have spent centuries being friendly to each other, yes a rivalry in interpretation of history but still friendly.
An still trading and interbreeding for generations together.

I guest we will fine out more next episode.

Puddle-Jumper
April 20th, 2011, 04:48 AM
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
April 20th, 2011, 06:42 AM
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
April 20th, 2011, 11:53 AM
This makes no sense. So how are humans into their billions then?

Trinary
April 20th, 2011, 12:16 PM
This makes no sense. So how are humans into their billions then?

Pornography. Lolz.

jelgate
April 20th, 2011, 01:53 PM
This makes no sense. So how are humans into their billions then?

Genetic mutations

SaberBlade
April 20th, 2011, 02:00 PM
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
April 20th, 2011, 02:34 PM
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:

http://wps.prenhall.com/wps/media/objects/489/501216/CDA48_2.jpg

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
April 20th, 2011, 03:57 PM
So does this all mean that Eli got busy with all the females on Destiny? Including Wray? :eek:

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
April 20th, 2011, 04:41 PM
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
April 20th, 2011, 06:31 PM
A fresh and unique adaptation of something that can never be proven in our lifetime.

N.C

Girlbot
April 20th, 2011, 06:42 PM
So does this all mean that Eli got busy with all the females on Destiny? Including Wray? :eek:

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
April 20th, 2011, 11:22 PM
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
April 20th, 2011, 11:25 PM
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
April 20th, 2011, 11:59 PM
doesn't that basically make this entire question based upon the genetic strength of the people we have ?

D Toccs
April 21st, 2011, 12:07 AM
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.

Shak53
April 21st, 2011, 04:44 AM
"With 80-however many people there were on Destiny, did they really have enough people to create a stable gene pool that would last 2000 years?"

Probably, but it depends on what interesting mating situations occur in the third or fourth generation. As long as it's a possibility, I don't have a problem with it. There was enough genetic diversity, although I expect that there would be an increase in birth defects for the first 75-200 years, maybe even a little earlier.

"But don't all you good Christians believe we started with just two people?"

Yes

"According to the Bible, we're all descendant from Adam and Eve (2 people). If 2 people are enough to eventually create a civilization of BILLIONS, why can't a group of 60-80 people form a civilization of MILLIONS (which is less) ?"

Our culture is stunningly biblically illiterate, which is why most people shouldn't even be discussing the Bible or Christian theology. The fallen state of nature and mankind with the corruption that went along with it also involved the degradation of the human genome. True, the Bible doesn't talk about the mechanism of inheritance as such, but it does talk in general terms about how when God first created Man, He created Him perfect and good. Since He is not a god of the dead but of the living, he did not create the human body initially to be subject to death, disease, suffering, or any form of corruption. It happened later when sin was introduced. Death was the consequence of sin.

That means Adam, Eve, and their children were free to "inbreed" without risk of passing on genetic mutations. The idea of corruption does not necessarily entail something that happens all of a sudden, but something that happens insidiously over time. At first, Adam, Eve, and their children and grandchildren were "safe," but over time as recessive mutations began to develop and thrive, inbreeding became more and more of a risk until at the the Pentateuch when the law specifically stated that close familial sexual relations were *now* forbidden.

As well, Adam and Eve probably had more genetic diversity than we do (esp. considering the bottleneck element of the Flood). If we go back to basic high school genetics, we understand for instance that there is a dominant gene for one eye colour and a weaker gene for another - the genotype and phenotype. While it's possible that a single person may have two genes that are essentially the same (the BB), Adam and Eve could have both had (Bb), although, I suppose there could have been four possibilities (say Bb and Aa).

So, yes, there is a case to be made that the Destiny crew may not have been able to sustain their population genetically, even if you believe that the human race came from two people.

"2000 years did not make an advanced society like that quite believable. Maybe they went back farther, like 20,000 years or something."

Yes and no.

Necessity is often the mother of invention. Human beings don't have long memories. After the second or third generation, they wouldn't have retained the knowledge if it wasn't immediately usable, esp. if they lived in too harsh or too pleasant conditions. I expect what would have happened is that some Novan populations were more advanced than others, but I don't expect SGU to discuss that. I had a hard time suspending disbelief throughout most of the episode.

jsonitsac
April 21st, 2011, 10:23 AM
Folks we all have a little bit of inbreeding in every one of us. The term is called pedigree collapse. If you traced your family tree back 30 generations you would find that you don't have over 1 billion ancestors. Chances are that you have a pair of cousins, typically second, third, or "removed" cousins. It will minimize chances of genetic flaws from being passed on, but obviously won't prevent it.

Clearly humans can develop large, sustainable numbers, from small groups of people. From what I've heard there may have only been less than 100 people who first colonized Australia thousands of years ago.

morrismike
April 23rd, 2011, 06:26 AM
So does this all mean that Eli got busy with all the females on Destiny? Including Wray? :eek:

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?

I don't believe that sociopathy is genetic but his genes for bad eyes have no place in a society without optomitrists.

morrismike
April 23rd, 2011, 06:27 AM
Folks we all have a little bit of inbreeding in every one of us. The term is called pedigree collapse. If you traced your family tree back 30 generations you would find that you don't have over 1 billion ancestors. Chances are that you have a pair of cousins, typically second, third, or "removed" cousins. It will minimize chances of genetic flaws from being passed on, but obviously won't prevent it.

Clearly humans can develop large, sustainable numbers, from small groups of people. From what I've heard there may have only been less than 100 people who first colonized Australia thousands of years ago.
so Novas is full of aussie chicks?

Ben 'Teal'c would WIN!!' Noble
April 24th, 2011, 06:28 PM
so Novas is full of aussie chicks?

Are you being sarcastic? :p.

morrismike
April 24th, 2011, 07:25 PM
Are you being sarcastic? :p.
ever been to OZ? you don't know what you're missing

tinerin
April 24th, 2011, 07:29 PM
ever been to OZ? you don't know what you're missing

Miranda Kerr...

thekillman
April 25th, 2011, 02:07 AM
No, the entire question is based on whether or not there are enough people to create a stable gene pool.


but that question is predecessed by the question "do the individuals have a sufficient genetic diversity"


given that they succeeded, it's likely that the Destiny crew has sufficient genetic diversity among themselves to get to a point where they can dampen the effects. like in IVF. which given their technological background, shouldn't take THAT long to develop.


i'd estimate about 4 generations to get their resource technology up to speed and after that, they can get to refining.


the most crucial things are setting up mines (not that hard, on an uninhabited planet it would lie on the surface), and setting up proper furnaces. 2000 years ago they couldn't even smelt iron on earth, Bronze was the standard. iron is superior to that.


the principle of advanced ore smelting isn't that advanced either, it just took damn long for humans to figure it out. the Destiny crew holds a massive repository of immensely valuable information that would speed up advancement in many ways.



and it has NOTHING to do with how shields work or how they repair the FTL drive. simply the concepts themselves are enough. tell them how hygiene works and disease will never get as bad as things like the plague. if we had vaccination 2000 years ago, things would look different.



there are so many aspects that they never knew or even could fathom back then that the Destiny crew can pass on to their children and create advancement. at the very least, Eli would've released some math on the subject and told their children to figure out the solution, while the Crew ensured they would quickly develop such tech.

slimjim
December 9th, 2011, 02:27 PM
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.

but I thought the entire human population was descended from only a few tens of thousands of Africans, according to your calculation (assuming I've understood it) there shouldn't even be 100,000 people on earth today
also does that mean that their can only be 53 people on the planet forever if they don't want genetic defects, even in like 10,000 years say?

Net effects unknown
April 9th, 2015, 09:55 PM
There seems to be the point of where the switch is made from stagnation to "rolling" exponentially.

The question remains then for me how destiny made is to exponentially without "going hungry" along the stagnation line of the curve.

Can that be done with apparently the wrong male to female ratio. And even if it could have been done, would they have had to make Wrey the Chief Breeding Officer (CBO); who assign pairs? lol

Franky, I, not having done the math, have a feeling that there is a minimum number x of people required to jump start a planet with people in the millions. and 60-80 doesn't quite do it.

I know from a documentary that sociopathy is mostly genetic, so someone should have been taking it slow. lol

Rush is the full blown psycho. Probably he would have been able to get the people from Ikarus to Earth but he wouldn't miss his last train to Destiny.

He would without hesitation come up with a number of "acceptable losses" of people he would sacrifice for what he believes is "the mission". Excluding himself of course. That number would be 100% no doubt. A bit like Locke's 'the Island demanded a sacrifice'.

Moreover, tried to frame the Col with murder. Did not report that he was implanted with alien tracking device. Did not report the discovery of the main bridge. Was talking to imaginary or Desitny created people. Whacko mad scientist.

I wonder what'd happen, if there is was a mission and Dr Rush gets all knowing or all powerful because of what he finds. Scary.

thekillman
April 10th, 2015, 03:09 AM
Franky, I, not having done the math, have a feeling that there is a minimum number x of people required to jump start a planet with people in the millions. and 60-80 doesn't quite do it.

Actually i believe 50-100 can do the trick. The numbers vary because it's not something you can do an actual experiment with. However, it does strongly depend on how diverse the gene pool is. Since none of them are relatives, this is already a good sign for genetic diversity. It also depends on other factors like genetic diseases and such. However, 80 can be done:


For example, the elephant seal was hunted down to around 20 seals by the late 1890's. Today there are around 30,000 and they are all pretty much the same genetically. (Because of the way elephant seals mate, all of the elephant seals around today could have come from a single father.)
http://genetics.thetech.org/ask/ask113


The estimated effective size of the founding population for the New World is about 70 individuals," said Jody Hey, a professor of genetics at Rutgers University.
http://www.livescience.com/289-north-america-settled-70-people-study-concludes.html


It's not perfect or risk free (safer numbers would be 160+) but it can be done, and in case of the seals (not humans but still....), has been done.