[Right: Bloodstain on the Shroud of Turin, "The Bloodstain on the Shroud of Turin are from Real Blood," Daniel R. Porter, 2 September 2008]
in this case my The Shroud of Turin blog, after removing the questioner's personal identifying information.
I will here give a quick public answer to you, `off the top of my head' and later add more details to flesh out my answers, including quotes. But this may take weeks rather than days, given other demands on my time. Your words are bold to distinguish them from mine.
----- Original Message -----
To: Stephen E. Jones
Sent: Tuesday, November 16, 2010 2:20 AM
>I have read a number of articles online regarding the Shroud and the science behind it. To be quite honest most of it confusing more than enlightening.
There are Internet pages about the blood on the Shroud of Turin, e.g.:
"Real Blood on the Shroud of Turin-DNA-Porphyrins," Daniel R. Porter, 6 November 2005.
"The Blood on the Shroud of Turin is Real: 2005 Facts," Daniel R. Porter, 4 December 2005.
"The Bloodstain on the Shroud of Turin are from Real Blood," Daniel R. Porter, 2 September 2008.
But if you really want to study the Shroud of Turin, you will need to read books on it. I recommend Ian Wilson's latest, "The Shroud : The 2,000 Year Old Mystery Solved" (2010). Or more popularly, John C. Iannone's "The Mystery of the Shroud of Turin: New Scientific Evidence" (2004). I hope to do a multi-part book review of Wilson's book. I have started a series, "Shroud of Turin: Burial Sheet of Jesus!" which will be the equivalent of an online book, but it will take me years to complete.
>I have reason to believe the Shroud is authentic. These reasons are more spiritual in nature than scientific. However I do believe the science for proof is right around the corner. My belief more comes out of the book. I believe we are in a time where God is revealing more and more spiritual truths from the book.
What is already known about the Shroud complements the Gospels' account of the suffering, death and resurrection of Jesus. But I doubt if there will be any more evidence from the Bible that will support the authenticity of the Shroud and vice-versa. What we already have is more than enough.
>I had a quick question regarding blood evidence.
Real human blood was found the bloodstain areas of the Shroud. The blood was type AB, which is consistent with the Man on the Shroud being Jewish ("Blood type: ABO and Rh distribution by country," Wikipedia, 13 November 2010), but it is not conclusive, because all blood tends to denature over time to become type AB.
>I read that DNA specifics were limited and if fact it was doubtful if enough DNA material existed to map.
Human male DNA was also found in the bloodstain areas of the Shroud. But it was fragmentary and degraded and so there is not enough DNA to construct a map of a single gene, let alone of a whole human genome.
>I believe I read there was some but that contamination was highly likely.
The Shroud has been handled by countless thousands of people in its at least 660-year history, any or all of whom could have left part of their DNA on its surface; so it is not possible to completely exclude that the DNA isolated from the bloodstained areas is a later contamination.
But the Shroud DNA isolation and identification was done by experts in that field, so it is more likely than not that that DNA was from the blood of the Man on the Shroud, whom all the other evidence points overwhelmingly to being Jesus.
However, we do not have any other copies of Jesus' DNA, nor of any of His relatives (Mt 13:55; Mark 6:3; Lk 1:34-36; Gal 1:19; Jude 1:1) to compare their DNA with that from the bloodstained areas of the Shroud. So the DNA evidence is necessarily inconclusive, apart from adding to the evidence that the blood on the Shroud is real, human blood.
> I was curious as to whether the samples available or if additional samples could yield enough information to determine a direct descendant of the man's who's image appears on the cloth?
No. Apart from the DNA from the bloodstained areas of the Shroud being fragmentary and degraded, we do not have any other independent sample of Jesus' DNA, DNA mutates over time, and the effects of genetic drift, it would be impossible to determine from DNA the "direct descendant" of anyone who lived ~2,000 years ago, or even ~660 years ago.
Furthermore, every human child receives half its nuclear DNA from each parent, one-quarter from each grandparent, one-eighth from each great-grandparent, and so on. Assuming an average of one generation every 20 years, there would be 100 generations in the last 2,000 years. Therefore, even if Jesus did have descendants (which the Bible - Isa 53:8; Acts 8:33; 1Cor 9:5 - indicates He didn't) his specific DNA configuration would have been so attenuated over ~2,000 years as to be effectively non-existent.
Granted that each child, male and female, receives 100% of its mitochondrial DNA (mtDNA) from its mother, and she 100% from her mother, and so on, mitochondrial DNA has only 37 genes, so it is too non-specific, and besides it also has mutated over time.
>A burning question I have been led to ask. I appreciate any clarity you may be able to bring on the topic for me.
I hope this has helped, albeit `off the top of my head' without supporting backup quotes, which I plan to add later.
>Gratefully your brother in Christ
It is good to hear from a fellow Christian who accepts the authenticity of the Shroud. Most Christians in my experience are either indifferent to the Shroud, or even hostile to it (as I was before 1995). But now the Shroud for me is, in addition to my salvation 43 years ago and my dear wife of 38 years, proof that God is both willing and "able to do immeasurably more than all we ask or imagine" (Eph 3:20)!