Actual Importance of Haplogroups

[Longbowman]

Some people seem to have some misinformed views on haplogroups - namely, a seeming belief that they are hugely important on an individual's genetic makeup, perhaps even phenotype and race. This is just a brief thread to explain the actual value of haplogroups:

1) mtDNA constitutes the smallest chromosome in humans

mtDNA consists of only 16,600 base pairs, which might sound a lot but humans have around 3.2 billion, which means it's only about 0.0005% of your genome. In terms of direct impact on the physical form, mtDNA only constitutes 37 genes, of which according to wikipedia, 13 are for proteins (polypeptides), 22 are for transfer RNA (tRNA) and two are for the small and large subunits of ribosomal RNA (rRNA). It has very little effect on the individual. Remember, your eye colour alone is determined by c. ~15 genes, so 37 is a very small amount.

2) YDNA is larger than mtDNA, at about 50 million base pairs, but that's still only around 1% of the male genome (females do not have a Y-chromosome, which should tell you how important it is vis-a-vis phenotype and race). Unsurprisingly, it's mainly involved in proteins that exist in males but not females. It is a fascinating chromosome, especially with regards to the differences between humans and other mammals.

3) So why are they so often cited in human genetics?

Because they're the only genes automatically handed down father-to-son, and mother-to-child, excluding mutations, which makes them useful for identifying racial groupings. So if 80% of Britons are R1b, then R1b becomes associated with Britons. But, even assuming YDNA chomosome X is exclusively Finnish in origin, if someone has YDNA clade X, all it means is 1 great great great great great etc. grandparent was Finnish - and thus YDNA isn't hugely relevant in determine the race of an individual. Similarly, not being clade X doesn't mean you aren't Finnish, it just means your great great etc. grandparent wasn't Finnish. The remaining 99%+ of your makeup could easily be Finnish.

http://en.wikipedia.org/wiki/Y_chromosome
http://en.wikipedia.org/wiki/Mitochondrial_DNA

1000th post!

[Stanley]

Yep. Haplogroups are useful for population history and can be interesting trivia, but they carry way too much clout on these boards. A lot of people make them out to be some huge determiner of their genetic makeup. Just take a look at the 23andMe community threads.

I think here at TA we had a thread a while ago polling people with I1 Y-DNA on their heights. Yeah...

[Baluarte]

Marginal use to determine prehistoric origin of certain populations, in order to improve our knowledge of history of ancient settling and migrations.

Out of niche science importance? Absolutely none

[Oneeye]

Yep. Haplogroups are useful for population history and can be interesting trivia, but they carry way too much clout on these boards. A lot of people make them out to be some huge determiner of their genetic makeup. Just take a look at the 23andMe community threads.

I think here at TA we had a thread a while ago polling people with I1 Y-DNA on their heights. Yeah...

+1

Haplogroups are much more useful in a collective point of view, rather than individual.

[Smeagol]

Haplogroups are absolutely meaningless. They don't say anything about a person.

[Damião de Góis]

Haplogroups are absolutely meaningless. They don't say anything about a person.

But there's a good chance you will guess where this person is from just by looking at the person's haplogroups.

[Atlantic Islander]

H1 is as boring as chalk.

[Longbowman]

But there's a good chance you will guess where this person is from just by looking at the person's haplogroups.

Unlikely. There's a good chance you can tell where that person's male line ancestry isn't from but most haplogroups are found over a very wide area.

[Gaita]

I mean, the haplogroups are helpful to a certain extent, they simply tell us the origins of our first male and female ancestor. Ofc they also play part in our total autosomal DNA as well.

[Styrian Mujo]

I calculated how much hg R,I and N each european country has and I got some pretty interesting results.