- #1
- 383
- 5
There are only a finite number of combinations of DNA that one can have while still being human so my question is what are the chances of two people having the same DNA?
But dna fingerprintting is done only at a few loci (edit-13 it seems for CODIS http://en.wikipedia.org/wiki/DNA_profiling )UltrafastPED said:Here they say 1 in 10^9, excluding identical (monozygotic) twins:
http://dnafingerprinting19.tripod.com/
This article goes into the details: http://en.wikipedia.org/wiki/DNA_profiling
Which is what it said in the references provided above ... though if the 13 loci are treated as independent, larger values are obtained. The Wikipedia article provides details as to why these larger numbers are not reliable....but probability should be somewhere around 1 by more than 1 billion*...
I am white, mostly of northern and western European descent, but with some Lakota blood; I also have black and oriental relatives of various shades ... just because two people look different does not mean that they are not related!mmm...interesting article...
http://articles.latimes.com/2008/jul/20/local/me-dna20
-slightly biased arguments but seems worth scrutiny...
Enough for what? Having known several sets of identical twins, I would say that neither DNA or fingerprints would have been enough for them. Having known them fairly well, I could also conclude that if one was involved, so was they other ... so in that case either _might_ be enough, but the circumstances also need to be considered: method, motive, opportunity.Are fingerprints enough?
Actually many cases are such that where only a partial match is possible due to degradation.UltrafastPED said:.Besides, identity requires 13 matches, not 9.with regard to said:The men matched at nine of the 13 locations on chromosomes, or loci, commonly used to distinguish people.
The FBI estimated the odds of unrelated people sharing those genetic markers to be as remote as 1 in 113 billion. But the mug shots of the two felons suggested that they were not related: One was black, the other white
Actually fingerprints are different for identical twins (http://en.wikipedia.org/wiki/Twin#Genetic_and_epigenetic_similarity) and DNA might be different too (http://www.scientificamerican.com/article.cfm?id=identical-twins-genes-are-not-identical)Enough for what? Having known several sets of identical twins, I would say that neither DNA or fingerprints would have been enough for them.
Er...sorryHaving known them fairly well, I could also conclude that if one was involved, so was they other ... so in that case either _might_ be enough,
Read only Doyle's; others are pure rubbish...Eg. http://www.youngsherlock.com/Read any Sherlock Holmes story ...
A case illustrating the opposite: conviction based only on DNA evidence presented (fallaciously according to http://plus.maths.org/content/os/issue55/features/dnacourt/index but I don't think the 'correct' interpretation would have affected much.) and all other evidence supporting innocence:Here is a conviction with no fingerprints or DNA, but only one person's eye witness testimony:
http://www.latimes.com/local/la-me-innocence-hearing-20131108,0,5797031.story#axzz2kAA8kk7Q
When the police and prosecutors want to close a case, they may go too far ... who is watching the watchers?