3 ms·

You're attacking a strawman. mtDNA can be used to track lineages. It's the dating of when branches occurred that is off because it assumes all differences are

You're attacking a strawman. mtDNA can be used to track lineages. It's the dating of when branches occurred that is off because it assumes all differences are due to mutations and not paternal contributions.

whatshisface 8y ago
That's a good insight - it's not whether or not the rate of paternal inheritance is high, it's whether or not the rate of paternal inheritance is high relative to the rate of mutation. What are those rates for mDNA?
samatman 8y ago
I am not. The rate of mutation is already not a constant, and so such dating is always approximate, there is a margin of error. If you wish to demonstrate that it is now "completely off" and "invalid", try harder. I call shenanigans.
gus_massa 8y ago
I'd have to take a look at the details, but I'm 99% sure that the important part is that the mitochondrial DNA has no crossover, so all the differences are due to mutations and it is a real tree. With normal DNA the crossover add some changes and in particular it mix the changes in one branch of the tree with the changes in the other branch of the tree, so it's not longer a tree. So my guess is that it will not change the dates too much, specially since he dates are calibrated by historical events. With made up numbers, something like "we know that this population reach here 10000 years ago and has 37 changes and that population reach there 20000 years ago and has 69 changes. This other population has 53 changes so after some complicated math, we estimate that they split 15000-1600 years ago. I guess that the size of the population at the bottlenecks will be slightly reduced, because IIUC they are not calibrated using historical data but using some mathematical models about how the size of the population affect the diversity. I don't expect a big change nevertheless.

3 ms·

You're attacking a strawman. mtDNA can be used to track lineages. It's the dating of when branches occurred that is off because it assumes all differences are

by droithomme 8y ago

whatshisface 8y ago
That's a good insight - it's not whether or not the rate of paternal inheritance is high, it's whether or not the rate of paternal inheritance is high relative to the rate of mutation. What are those rates for mDNA?
samatman 8y ago
I am not. The rate of mutation is already not a constant, and so such dating is always approximate, there is a margin of error. If you wish to demonstrate that it is now "completely off" and "invalid", try harder. I call shenanigans.
gus_massa 8y ago
I'd have to take a look at the details, but I'm 99% sure that the important part is that the mitochondrial DNA has no crossover, so all the differences are due to mutations and it is a real tree. With normal DNA the crossover add some changes and in particular it mix the changes in one branch of the tree with the changes in the other branch of the tree, so it's not longer a tree. So my guess is that it will not change the dates too much, specially since he dates are calibrated by historical events. With made up numbers, something like "we know that this population reach here 10000 years ago and has 37 changes and that population reach there 20000 years ago and has 69 changes. This other population has 53 changes so after some complicated math, we estimate that they split 15000-1600 years ago. I guess that the size of the population at the bottlenecks will be slightly reduced, because IIUC they are not calibrated using historical data but using some mathematical models about how the size of the population affect the diversity. I don't expect a big change nevertheless.