2008-04-05, 18:12 | Link #121 | |
Paparazzi
Join Date: Mar 2008
Age: 41
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The possibility is 50% as alleles of a parent not carrying a mutated allele are irrelevant as you can't inherit both alleles of a single parent. However each parent carries two alleles not one. And last I checked we were discussing survival of the unexpressed recessive genetic trait of a singular source assuming that the genetic lineage is not crossed with itself thus potentially fortifying it. Even if cousins whom grandparent has the mutated allele would procreate the possibility of both parents carrying the mutated allele are 25%. Second cousins 12,5% and so on. I suck at maths so correct me if I'm wrong. But indeed if both parents are carrying the mutated allele the possibility of child inheriting it is 75%. Last edited by escimo; 2008-04-05 at 20:45. Reason: Screwed up the maths. |
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2008-04-06, 03:57 | Link #122 |
I disagree with you all.
Join Date: Dec 2005
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I'm not sure you're posing the problem in the right term. For that matter, I'm not sure what terms you're posing it in.
Define the question better. If all we know is that a grandfather has one mutated allele, and two of his grandchildren have kids together, the probability of that kid having the allele is 2 x 0.25 x 0.75 x 0.5 + 0.25 x 0.25 * 0.75 ~ 23%. But knowing that is pretty useless to knowing the probability that the allele itself will survive. Too many constraints. If the first mutant has two or three kids who live to have two or three kids and so on... Every generation, the number of carriers increases, thus making it harder to weed that allele out of the genepool. But calculating the exact probabilities is: - a pain, especially since with such small numbers we can't use the laws of averages - impossible without deciding on the distribution for the number of kids, and the probabilities of marrying a close relative. Note, unless that gene decides something important and the mutation is drastic, whether an allele is dominant or recessive has nothing to do with its survivability. |
2008-04-06, 04:36 | Link #123 |
Paparazzi
Join Date: Mar 2008
Age: 41
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True. Just makes it more interesting in terms of evolution as the trait dictated by the mutated gene would have to be expressed in numbers at least eventually. I don't think one popping up somewhere every 50 years or so would fit the definition as even after it's expressed the genetic base would need to remain relatively wide to keep the genome strong. Counting those probabilities is way beyond me.
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2008-04-06, 12:38 | Link #125 |
Gregory House
IT Support
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escimo, I feel you're overcomplicating the problem needlessly. I don't know if it's because you don't have a very clear understanding of how natural selection works, or because you really want to feel adding low-chance numbers somehow proves God's intervention.
Evolution is simple. Mutations occur, and that much has been proven all over the place. Mutations make the cell generate new kinds of proteins, and new kinds of proteins are used for new kinds of purposes. Many of those purposes are completely useless, and will probably only hamper the cell's ability to reproduce itself, but sometimes, useful proteins or ways of combining old proteins appear, like the bacterial flagellum. That improvement, even if it happens on a single being, will become a permanent trait if it's useful enough--Nature measures usefulness in terms of reproduction ability. If the improvement allows the cell to survive and reproduce itself further, then the DNA of its prole will keep that trait. Of course, this is only when talking about single cellular division and not sexual reproduction, but even if the traits are recessive, they stay. If the traits are recessive, though, it means they're not as useful anyways, precisely because they are recessive, and thus the members with those traits have less chance of having a prole which fully shares that trait.
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2008-04-06, 16:19 | Link #126 | |
Paparazzi
Join Date: Mar 2008
Age: 41
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Quote:
I have no urge to prove god's existence nor disprove evolution as a theory. I just personally don't find evolution theory plausible as it is and I believe I'm entitled to do so. I remember someone pointing out that science is not a democracy. So you could call me a member of the opposition. The simile is quite fitting considering that I'm just about as qualified to discuss this as most of the politicians are at politics. I have no hardcore facts to provide to back up any of my views but if the result of expressing them results in a conversation this interesting don't really see the harm in bringing them forth. This is just a subject I find interesting. And I don't feel you need to get dead serious about it. I find little other reason than just for the fun of it, of discussing evolution, genetics or even existence of god on AnimeSuki. Not exactly what I'd call an appropriate place for serious scientific debate. |
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2008-04-06, 18:01 | Link #127 | |
Gregory House
IT Support
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Quote:
If you don't cross the imaginary line between religion and science, everything's all right with the world.
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