Philip Dei
Thu, Jul-18-02, 01:04
I just want to make a side point about mtDNA, to micheal and
to John. If you will think way back before Tishkoff, before
ZFY and the other genetic studies very few people took the
mtDNA studies very seriously. And Micheal in and of itself
Vigilante et al does not define human expansion.
Its the other studies The fact that Y chromosome was recently
fixed. The fact that Tishkoff et al shows diversity in africa
for at least one loci is 8 times that outside of africa. The
fact that 1/3rd of autosomals and X-linked loci have fixed
within the last 400 ky.
These give the mtDNA studies the legs it needs to stand on.
Almost all the composite molecular studies agree that humans
went through a constricted population size. Any fool can
compare human variation to chimpazee (at 2 to 3 magnitudes
small pop size) and realize that there must have been a
constriction. The issue in not that it occurred but where.
The power of mtDNA, particularly HV1 is there is alot of
information about population movements in a very compact
segment of DNA, thats why we use it. More or Less it
recombines at a fraction of the rate of autosomals, but [ahem,
Gisele] its not clear what fraction that is. Given there are
now 6000 mtDNA HV1 or HV2 sequences out there, someone other
than myself thinks these are important. If you MREH guys were
so sure of PDAH1 is so important, why haven't we seen more
PDAH1 sequences published [ahem].
mtDNA is useful in tracing the movement of populations and it
is generally (but not always) useful in creating the temporal
qualifiers on those movements. Someday in the near future we
will start getting whole genome studies of the 100s or 1000s
of mtDNA which we can then trace to 1000s of years versus 10s
of 1000s of years human migrations. By that time I sure hope
you guys have figured it out.
Or Mikey, let me put it to you like this, since you HATE mtDNA
so much (chuckle), Why don't you do for PDAH1 what was done
for mtDNA HV1, put the ole money where your mouth is?
Philip <pdeitik at bcm.tmc.edu
to John. If you will think way back before Tishkoff, before
ZFY and the other genetic studies very few people took the
mtDNA studies very seriously. And Micheal in and of itself
Vigilante et al does not define human expansion.
Its the other studies The fact that Y chromosome was recently
fixed. The fact that Tishkoff et al shows diversity in africa
for at least one loci is 8 times that outside of africa. The
fact that 1/3rd of autosomals and X-linked loci have fixed
within the last 400 ky.
These give the mtDNA studies the legs it needs to stand on.
Almost all the composite molecular studies agree that humans
went through a constricted population size. Any fool can
compare human variation to chimpazee (at 2 to 3 magnitudes
small pop size) and realize that there must have been a
constriction. The issue in not that it occurred but where.
The power of mtDNA, particularly HV1 is there is alot of
information about population movements in a very compact
segment of DNA, thats why we use it. More or Less it
recombines at a fraction of the rate of autosomals, but [ahem,
Gisele] its not clear what fraction that is. Given there are
now 6000 mtDNA HV1 or HV2 sequences out there, someone other
than myself thinks these are important. If you MREH guys were
so sure of PDAH1 is so important, why haven't we seen more
PDAH1 sequences published [ahem].
mtDNA is useful in tracing the movement of populations and it
is generally (but not always) useful in creating the temporal
qualifiers on those movements. Someday in the near future we
will start getting whole genome studies of the 100s or 1000s
of mtDNA which we can then trace to 1000s of years versus 10s
of 1000s of years human migrations. By that time I sure hope
you guys have figured it out.
Or Mikey, let me put it to you like this, since you HATE mtDNA
so much (chuckle), Why don't you do for PDAH1 what was done
for mtDNA HV1, put the ole money where your mouth is?
Philip <pdeitik at bcm.tmc.edu