In my last post, I explained how one might find “virtual immortality” by having 99.9% of their genes present within one’s offspring. If these offspring are your children which each hold a random 50% of your genes, we only need 10 kids. But what about achieving virtual immortality if you’ve been dead for half a century?
Wiston Cap has been dead that long, but as of 10 years ago there wasn’t a single Border Collie born in the United Kingdom that didn’t have his genes. In fact, the average ISDS border collie is 13.3% Wiston Cap, making him the equivalent of every dog’s great grandfather.
So how many random BCs would we need to collect to reconstruct old Wiston Cap in bits and pieces? With the 10 dogs we had before, we’d be 72.32% of the way there. We’d get to 90% with 18 dogs, and all the way to 99.91% with only 49 dogs. Any 50 random Border Collies and some well informed cherry picking of their genes and we’d have a complete library of Wiston Cap.
And that’s just looking at the genes that came down from Wiston Cap himself, not taking into account our ability to find genes that ended up in Wiston Cap from his ancestors like Wilson’s Cap ISDS 3036, who had an influence on Wiston Cap of 21.5% and who can be found in all ISDS dogs with an average representation of 17.2%. Now before you ask if most of that 17.2% is mostly from Wiston Cap, it’s not, only 2.9% of Wilson’s Cap’s 17.2% is from Wiston Cap further popularizing his genes.
This is just a thought experiment as there isn’t a means to currently identify which genes would have come from Wiston Cap specifically, even if we could single out individual genes and recombine them if we did know. Interestingly though, we wouldn’t need an actual physical marker for these genes to make a really good educated guess. If we took a wide inventory of alleles from the breed, we could rule out any alleles that fell below Wiston Cap’s 13.3% representation, since he was bred so far and so wide and his genes have now reached a stable 13.3% of the breed.
Testing and pedigree analysis would give us a pretty clear picture of what we would expect to see and then we could simply match which alleles fit the pattern. It won’t be so long before someone can say of Wiston Cap:
We can rebuild him. We have the technology.
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Chris,
Could you give some more information on the math behind your table? Just curious since the math cannot be done in the same way as your virtual immortality post.
Hey Me,
The math is actually the same, we just have to be more careful when the relatedness quotient isn’t 50%, because the 50% case simplifies nicely so we can simply sum (1/2)^n, from n=0 to N. This is actually the same formula for both the level of homozygosity in the “Selfing” form of inbreeding (because if we always mate twins then there’s always a 50% chance that we’ll get that last unpaired gene to pair up alleles), and the expected contribution of an additional first generation offspring in our virtual immortality concept (a child will likely donate 50% of the genes we have not yet captured).
This is so simple because the doubling effect and the percent of the remaining genes we’re dealing with are both 50%
For a population that only contributes 13.3%, I set up a spreadsheet. The first dog contributes 13.3%. The second dog contributes 13.3% of what is left, namely 13.3% x (100%-13.3%) = 13.3% x 86.7% = 11.53%. We add this to 13.3% to get 24.83% captured with two dogs.
.133 x (1-.2483) + .2483 = .3483
.133 x (1-.3483) + .3483 = .4350
etc.