GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2006-04 > 1144220458


From: "brian quinn" <>
Subject: RE: [DNA] Fibonacci and Probability in the Library
Date: Wed, 5 Apr 2006 17:00:58 +1000
In-Reply-To: <2ce201c65862$c89efde0$022aa8c0@davros>


Interesting that probabilities of borrowing a book are at the back of this
stuff


I liked this story seems a bit pertinent to the list. I don't understand
Binomial distributions to be able to say anything useful. But

Something to do with the more markers you measure the more likely you are to
find differences in the population. In other words the more you measure the
closer you get to a dna fingerprint of an individual- especially as we are
all different (except for twins of course- and they will still have the post
fertilization somatic differences).

Are these graphs what you mean
http://www.roperld.com/YMarkersProbabilities.htm?

Nice read: http://www.garfield.library.upenn.edu/bensman/jasistprobart.pdf

I liked this story, from the paper above about normal curves dominating
thinking in the 19th century.

"This thinking dominated Quetelet's approach to the definition of
sets. His reasoning in this matter is summed up by Stigler
(1986):
What was true of astronomical observations would also be
true of heights of men, of birth ratios, and of crime rates.
Now, if homogeneity implied that observations would follow
the normal law, then why not use this device for
discerning homogeneity? Simply examine the distribution
of a group of measurements. If they fail to exhibit this form,
then this is surely evidence of lack of homogeneity-or at
least evidence that the primary inhomogeneities are not in
the nature of a large number of accidental (independent,
random, of comparable force and size) causes. If they do
exhibit this normal form, then this is prima facie evidence
that the group is homogeneous and susceptible to statistical
analysis as a group, without distinguishing the members of
the group by identifying labels. (p. 205)
Quetelet used this type of reasoning in analysis of heights of 100,000
French conscripts, coming to the conclusion
of large-scale draft evasion because of the excess of
men in the shortest class exempt from service. In another
study of the heights of French conscripts-this time from
the Department of Doubs in eastern France in the period
1851-1860-Adolphe Bertillon applied the same type of
logic. Finding that the heights did not exhibit the usual
symmetrical shape but rather had two modal values, Bertillon
hypothesized that the population of Doubs consisted of
two human types, one short and one tall. His theory seemed
confirmed when his colleague Lagneau subsequently found
that the inhabitants of Doubs were primarily of two different
races, the Celts and the Burgundians. Bertillon's investigations
bore an uncanny resemblance to the later work by
Weldon that led Pearson to challenge the normal paradigm."

Who needs haplotype testing just use a ruler!


quinny


-----Original Message-----
From: Jason S. Clary [mailto:]
Sent: Wednesday, 5 April 2006 1:41 PM
To:
Subject: Re: [DNA] Fibonacci

Oops.. I think that may have unintentionally come across the wrong way.

It's impressive that you noticed the connection between the situation and
the number. Good job. ;)

Not many people see patterns like that...

I'm still baffled why the slope of percentages of exact marker matches in a
reasonably random database tend to drop off with the addition of new markers

according to the Inverse Square Law. Excactly how does a physics law equate

to genetics.. ;)


----- Original Message -----
From: "Jason S. Clary" <>
To: <>
Sent: Tuesday, April 04, 2006 8:28 PM
Subject: Re: [DNA] Fibonacci


> It's not exactly a new idea... Leonardo of Pisa (a.k.a Fibonacci ~1200)
> used it to describe population growth and claimed it was "encoded in the
> ancestry of a male bee."
>
> The concept is the same in bees although for different reasons. An
> unfertilized egg hatches a male and a fertilized hatches a female so the
> males always have one parent and the females always two.
>
> That's why it's named after him and not the Indian mathematician Pingala
> Chhandahshastra in 500BC who first described it while investigating
> methods of bin packing. ;)
>
>
>
> ----- Original Message -----
> From: "John Lerch" <>
> To: <>
> Sent: Tuesday, April 04, 2006 8:13 PM
> Subject: [DNA] Fibonacci
>
>
>> Apologies for those who were confused about my discovery about the
>> Fibonacci sequence as it applies to the Xchromosome. I was behind in my
>> reading and so when I realized the Fibonacci nature and I recalled that
>> no one had mentioned it earlier when we were discussing the Xchromosome
>> contributions as breaking up more slowly than ordinary autosomal
>> chromosomes, I assumed that no one had noticed the Fibonacci nature. But
>> having gotten thru some more posts I saw AnnT quoting the correct numbers

>> and JohnC even giving the correct name of Fibonacci. Well it's still
>> cool to get to the finish line without any assistance.
>> JAL
>>
>>
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