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Plant Sciences, Zoology & Evolution / A word for non-human animal?
« on: 19/02/2011 15:01:29 »
Is there a technical word (probably latin), for non-human animal (or just non human)?
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Even so, you still have 4 possible alleles of each gene to consider, and SNPs.
Not particularly because you are concentrating on making the numbers crunch whereas I am basing it on what actually happens and what is feasible.Sorry if i appeared patronising
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I'm not sure about where you get the half.
I have always wondered why China's population is still increasing with a 1 child policy.
True... except there will be 1 sperm, and 1 egg that has the exact opposite genes.
The likelihood of the second egg getting fertilized either at the same time (fraternal twins), or during successive pregnancies is non-zero. So, if fertilization is "random", with fraternal twins, it would depend on the number of sperm per ejaculate, and would be around 1 in 280 Million (assuming both sperm are viable in the same ejaculate).
For successive pregnancies, it depends on the chance of that second egg getting fertilized times the probability of the "anti-twin" sperm, which as mentioned, with no crossovers, it is actually a smaller number 1 in 223 for the men (1 in 8,388,608), but in reality is a more rare case due to the crossovers.
Without getting that second egg... the obviously the number is the same as the one calculated above... 1 in 70 trillion.
With you now.No,
Even so, you still have 4 possible alleles of each gene to consider, and SNPs.
You could make a mathematical model for most things, but that does not mean you can exclude factors that change the numbers that you crunch.
Hmm, interesting.PS Im not sure how you would do it, but your calculation doesn't give a 0 probability if the average number of children per family was 1 (which it should be). Im not sure where you would incorporate this.Cousins marrying Cousins?
Oedipus?
A stable (or healthy slowly declining) population is 1 kid per parent, or 2 kids per couple (excluding Oedipus, of course which would change your averages).
Anyway, the diffusion of genes in the population is so rapid that the probability of "twins" in the general population drops to virtually zero. The problem is that in the general population, you don't have 23 or 46 chromosomes... but virtually every chromosome is unique due to random variations and cross-overs. The only way to do the calculation would be in a very tight tribal society... and still you'd need to enforce no mutations or crossovers. Did we talk about spontaneous mutations? I think the spontaneous mutation rate is on the order of a few hundred base pairs per generation.
I'm still thinking the chances are 1:246, rather than 1:223. (perhaps dividing by a factor of 2).
As I believe it would be the same to line up 23 maternal and 23 paternal chromosomes and dividing them... vs lining up all 46 chromosomes (keeping maternal and paternal pairs separate)... and dividing them.
Or, as I discussed earlier, giving each maternal chromosome a 0/1 bit, and each paternal chromosome a 0/1 bit, thus 46 bits total.
Now...
An interesting calculation would be the probability of getting an "anti-twin" (without scientifically creating it).
During telophase, every egg and every sperm has a pair with all the opposite chromosomes. The male sperm, without fertilization treatment, of course, would die within 9 months. But, perhaps it could happen with fraternal twins.
Keep in mind that through fertilization treatment, it is relatively easy to create identical twins, either both born at the same time, or later dates.
Ok...
I think your numbers are off. Here is how I'm calculating it.
If you have 23 pairs of chromosomes... from the father... of which you have to select half of the chromosomes... you can think of it as binary numbers. You get either chromosome 0 or 1. So, there are 223 combinations.
Errr not entirely no. If you are calculating the odds of identical genomes occurring then alleles feature heavily into that. They are not just simply an essence.
And then you have to consider SNPs...... I am no maths guru, but I would guess the calculations are impossible to do.
thats the rough number of combinations any two parents can have - ie you get half as a selection from your fathers and half as a selection from your mothers. But my mother and your mother have different selections to choose from - although they did both call their sons Matthew!
Have you factored in alleles into it?Alleles are just an essences of the genetic code. What it codes for. Its all contained on the chromosomes, so yes.