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    #76
    "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.

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      #77
      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.

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        #78
        Originally posted by erotavlas View Post
        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?
        I don't believe that sociopathy is genetic but his genes for bad eyes have no place in a society without optomitrists.

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          #79
          Originally posted by jsonitsac View Post
          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?

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            #80
            Originally posted by morrismike View Post
            so Novas is full of aussie chicks?
            Are you being sarcastic? .

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              #81
              Originally posted by Ben 'Teal'c would WIN!!' Noble View Post
              Are you being sarcastic? .
              ever been to OZ? you don't know what you're missing

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                #82
                Originally posted by morrismike View Post
                ever been to OZ? you don't know what you're missing
                Miranda Kerr...

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                  #83
                  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.

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                    #84
                    Originally posted by carmencatalina View Post
                    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?

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                      #85
                      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.

                      Comment


                        #86
                        Originally posted by Net effects unknown View Post
                        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...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.

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