Notices
Results 1 to 12 of 12

Thread: So technically all life is inbreeds according to abiogenesis

  1. #1 So technically all life is inbreeds according to abiogenesis 
    Forum Ph.D. Raziell's Avatar
    Join Date
    Sep 2008
    Posts
    928
    Right?

    Because if all life came from one primordial soup that means all life on this planet is related from one source? So the tree in my garden and myself are both decendants from grandpa buildingblock the 1st?

    Im more posting this in a "joking" manner than seriousy, but still curious


    A lie is a lie even if everyone believes it. The truth is the truth even if nobody believes it. - David Stevens
    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Bachelors Degree
    Join Date
    Apr 2009
    Posts
    416
    yes, it's true to an extent. great*10^1000000 grandpa single-cell also grandfathered other species, other genuses, even other classes of organisms. and even in more recent times, we can trace the whole human race back to a few groups from africa. the propability that you and your sexual partner don't share at least one of these anscestors is incredibly low. essentially all sexual reproduction is incest to some extent.

    of course great grandpa single-cell and many generations of his descendants weren't practicing sexual reproduction. they were practicing reproduction via mitosis.


    physics: accurate, objective, boring
    chemistry: accurate if physics is accurate, slightly subjective, you can blow stuff up
    biology: accurate if chemistry is accurate, somewhat subjective, fascinating
    religion: accurate if people are always right, highly subjective, bewildering
    Reply With Quote  
     

  4. #3  
    Forum Ph.D. Raziell's Avatar
    Join Date
    Sep 2008
    Posts
    928
    Quote Originally Posted by saul
    yes, it's true to an extent. great*10^1000000 grandpa single-cell also grandfathered other species, other genuses, even other classes of organisms. and even in more recent times, we can trace the whole human race back to a few groups from africa. the propability that you and your sexual partner don't share at least one of these anscestors is incredibly low. essentially all sexual reproduction is incest to some extent.

    of course great grandpa single-cell and many generations of his descendants weren't practicing sexual reproduction. they were practicing reproduction via mitosis.
    Thanks! good answer.

    Mitosis is self replication i assume.

    Also one more thing if you dont mind. If we saw a planet in its early stages that would later support life... could we send a small space ship there with random life forms (Example sake: Bacteria, seeds etc) and "drop it" there and it could survive to further develop life?

    Or would the basic building blocks on this new planet need to be created naturally by this planets environment to survive and replicate under its conditions?
    A lie is a lie even if everyone believes it. The truth is the truth even if nobody believes it. - David Stevens
    Reply With Quote  
     

  5. #4  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    Of course we cannot be sure of any of this. We have no way of knowing what went on in the early days following abiogenesis.

    Bacteria swap DNA in a very promiscuous fashion, including between different species. It is quite possible that such swapping also happened among the first life forms. We may be descended from any number of separately formed organisms from original abiogenesis.

    I am not saying that is likely. Just that we cannot exclude it.
    Reply With Quote  
     

  6. #5  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,046
    Probably the first life forms reproduced asexually. There's no way to say that for sure, of course, but even today there are some life forms that don't need mates to reproduce.
    Reply With Quote  
     

  7. #6  
    Forum Bachelors Degree
    Join Date
    Apr 2009
    Posts
    416
    raziell: you question is too vague for a yes or a no, but i'll give you a more verbose answer.

    seeds need only a few things in order to grow into a full plant and reproduce. they need carbon dioxide in the air, light energy that they can use for photosynthesis, and many need nitrogen fixing bacteria in the soil, although some plants can fix their own nitrogen. so if the planet has these things then the plant has a good chance of surviving.

    the term "would later support life" probably means you've got some complex organic chemistry going on somewhere. however it isn't specific as to what the physical conditions are like. if you meant "earth-like" then the Ph would be in the right range for most detrivores, autotrophs, and heterotrophs we have on earth. the temperature would also be somewhere between 0C and 100C, between 10 and 50 is usually best for life on earth, although it certainly can survive in much higher and lower temperatures.

    the planet certainly wouldn't have to develop its own life. if the planet was one we deemed could later support lifeforms and was currently developing its own, we could (relatively) easily biologically engineer a species that was ideal to survive, multiply, and quickly evolve on that planet. this does not mean that any old earth-born lifeform could survive there. it is theoretically possible to engineer species which can thrive in conditions that we consider harsh(nature produces many such organisms, chemoautotrophs that live near hydrothermal vents in the ocean for example).
    physics: accurate, objective, boring
    chemistry: accurate if physics is accurate, slightly subjective, you can blow stuff up
    biology: accurate if chemistry is accurate, somewhat subjective, fascinating
    religion: accurate if people are always right, highly subjective, bewildering
    Reply With Quote  
     

  8. #7  
    Forum Freshman
    Join Date
    Oct 2010
    Location
    The Netherlands
    Posts
    24
    That means we're incest machines!
    The only thing that saves us from the bureaucracy is inefficiency. Eugene McCarthy
    Reply With Quote  
     

  9. #8  
    Forum Bachelors Degree
    Join Date
    Apr 2009
    Posts
    416
    on the topic of incest:

    doesn't incest actually lead to a more pure gene pool? think about it.

    take for example sibling 1a(male) and sibling 2a(female) who share a common mother and father. if sibling 1a were to mate with sibling 2b(female, second parental group) and sibling 2a mated with sibling 1b(male, with the same mother and father as 2b) then we would have a non-inbreeding situation(assuming the parents aren't related in some way).

    let us also assume that siblings 1a and 2a are both carriers for recessive detrimental gene C, and sibling 1b and two b are carriers of recessive detrimental gene D.

    assuming each mating pair creates four offspring then we would expect to see two non-carriers, two C carriers, two D carriers, and two carriers of both C and D. (i used 4 rather than two because of the next part, so the data can be compared easily)

    the gene pool is just as muddied by detrimental recessive genes as it was before, there is a total of four recessive genes that will be passed to the next generation if these offspring go on to mate.

    now let us look at an inbreeding situation:

    rather than 1a mating with 2b, he mates with 2a. and 1b doesn't mate with with 2a, instead mating with 2b.

    if each of these groups mates and produces 4 offspring then it is expected that we will see:

    group 1:
    one non-carrier, two C carriers, and one double C

    group 2:
    one non-carrier, two D carriers, and one double D

    now here's the interesting part. if C and D are detrimental genes then double C and double D are less likely to mate than their non-carrier and carrier siblings. so for a good percentage of the time we can consider them non-existant in the gene pool.

    thus our produced gene pool with the inbreeding contains two non-carriers and four carriers of various detrimental genes.

    our pool with no inbreeding however produced two non-carriers, four carriers, and two double carriers.

    now in the beginning i mentioned how inbreeding made the gene pool more "pure" what did i mean by that? what i meant is that if we randomly select one individual to mate with a newly introduced individual, what are the chances that the next generation will recieve detrimental genes?

    in order to calculate this we must simply take the number of carriers over the total population. in the inbreeding group this is 4/6 = 2/3 = about .6667 = about 66.67% propability. in the non inbreeding group the number is either(if we don't count the double carriers twice) 6/8 = 3/4 = .75 = 75% propability or (if we do count them twice) 8/8 = 1 = 100% propability.

    clearly we can see from this simple thought expirement that although i'd hate to mate with any of my cousins, it is a service to the species if i do.

    that raises the question, if inbreeding is benificial to the species then why did the human race develop to consider it a taboo?
    physics: accurate, objective, boring
    chemistry: accurate if physics is accurate, slightly subjective, you can blow stuff up
    biology: accurate if chemistry is accurate, somewhat subjective, fascinating
    religion: accurate if people are always right, highly subjective, bewildering
    Reply With Quote  
     

  10. #9  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    Saul

    It has been done experimentally. If a small population interbreeds over many generations, there is a very high mortality for a few generations. In some experiments, that has been sufficient to render that population extinct. In other experiments, the population eventually weeded out the harmful genes and ended up genetically healthy.

    And, no. I do not want to see this happen to humans. The price is too high.
    Reply With Quote  
     

  11. #10  
    Forum Masters Degree Golkarian's Avatar
    Join Date
    Nov 2008
    Posts
    510
    One of the major reasons it is unhealthy concerns genetic diseases. Most genetic diseases that involve a broken gene are recessive, since if you have one allele that produces and one that is broken the working allele will pick up the slack.

    But say your grandparent had a recessive gene for a genetic disease, then it is more likely for your children to have the disease if you procreate with a cousin. But if you procreate with someone else it is less likely that they have the exact same recessive allele. So it is much more unlikely that your kids get a genetic disease.
    Reply With Quote  
     

  12. #11  
    Forum Bachelors Degree
    Join Date
    Apr 2009
    Posts
    416
    thank you for that skeptic. do you know the name of the study? or perhaps who did it? a link would help.

    and golkarian i never said anything that disagrees with that. i showed that inbreeding does actually make your kids more succeptible to inbreeding. but under the assumption that the kids with the genetic disease will often not reproduce, we can see that this practice in fact purifies the gene pool.

    skeptic, i can understand your hesitation about doing that with the human population but we have over six billion people. our species will obviously not go extinct from a few generations of inbreeding. and the positive effects on our collective genome are immense.

    obviously you can't say "well everyone has to inbreed for x years" because it's morally wrong. but just making it legal will make a small percentage of people voluntarily inbreed and purify their own genome.
    physics: accurate, objective, boring
    chemistry: accurate if physics is accurate, slightly subjective, you can blow stuff up
    biology: accurate if chemistry is accurate, somewhat subjective, fascinating
    religion: accurate if people are always right, highly subjective, bewildering
    Reply With Quote  
     

  13. #12  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,843
    Saul

    My information came from a Scientific American article on inbreeding some years back. They combined the data from a range of experiments.

    And no. We do not need to permit inbreeding in human populations. There would be a great deal of human misery resulting and no benefit. Some time in the next 100 years, it is predictable that human genetic modification will begin. As this new technology improves, it will become cheaper (hence available to more of the population), and eventually everyone will be descended from those who applied this technology.

    A parent who cares for his/her kids (and who does not?) will ensure that those kids get the best opportunities genetically as well as in other ways. This means that inbreeding as a tool for eliminating harmful genes will be totally unnecessary.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •